Mindfulness for adult ADHD
Effectiveness of Adapted Mindfulness Training
and
Protocol Development for Stand-alone Mindfulness
Alicia de Vries
Supervisor UvA: Prof. dr. M.E.J Raijmakers
Supervisor Radboud Centre for Mindfulness: L. Janssen & Prof. dr. A. Speckens Second assessor: dr. B.R.J Jansen
Abstract
Attention Deficit Hyperactivity Disorder (ADHD) places a substantial burden on adult patients. First-line treatment of ADHD is pharmacological therapy, however not all patients benefit from it. A plausible psychosocial intervention is mindfulness training, which involves the self-regulation of attention that can be cultivated through
meditation. Nevertheless, it is unclear whether a mindfulness protocol should be adapted to an ADHD population or can be delivered in its original form. Therefore, this research consisted of two studies. First, we investigated the effect of mindfulness with a psychoeducation module (MBCT+) on ADHD symptoms. Second, we evaluated the feasibility and acceptability of a stand-alone mindfulness protocol (MBCT) for adult ADHD by conducting a pilot study. Quantitative and qualitative analyses were performed.
Since attention regulation is a core feature of mindfulness, we expected both types of mindfulness to be effective in the treatment of ADHD. Moreover, self-compassion as possible working mechanism of mindfulness for ADHD was investigated.
Introduction
Attention Deficit Hyperactivity Disorder (ADHD) is a neurobiological developmental disorder with a high persistence into adulthood characterized by inattention and/or hyperactivity-impulsivity (American Psychiatric Association, 2000). It affects approximately 2.5% of the adult population worldwide (Simon, Czobor, Bálint, Mészáros, & Bitter, 2009). In line with this finding, the prevalence of ADHD among adults in a Dutch population is 2.1% (Tuithof, Ten Have, van Dorsselaer, & de Graaf, 2014).
Although different categories of ADHD are recognized (inattentive subtype, hyperactive-impulsive subtype and a combined subtype), certain characteristics are frequently identified. Adults with ADHD experience persisting symptoms, such as attentional problems, disorganized behavior, and problems in self-regulation (Newark, & Stieglitz, 2010). ADHD has often been associated with weaknesses in executive functions (Willcut, Doyle, Nigg, Faraone, & Pennington, 2005), defined as the capacity of ‘monitoring and regulating thought and action, to plan behaviour, and the inhibition of inappropriate responses’ (Goswami, 2008, p. 295).
ADHD can be disruptive to various areas of functioning. For instance, adult ADHD is associated with poor work performance (de Graaf et al., 2008), relationship difficulties (Harpin, 2005), and higher susceptibility to substance abuse (Biederman, Wilens, Mick, Faraone, & Spencer, 1998). Adult ADHD also places a substantial economic burden on patients and their families (Matza, Paramore, & Prasad, 2005). As such, treatments for ADHD that may effectively alleviate symptoms and reduce
problem aggravation in adulthood are highly relevant.
Although first-line treatment for adult ADHD generally consists of
pharmacotherapy (Bitter, Angyalosi, & Czobor, 2012; Vaughan, March, & Kratochvil, 2012), not all patients benefit from it. First, some individuals may respond partially whereas others may not respond at all (Wilens, Biederman, & Spencer, 2001). Second, patients may experience such severe side effects (emotional outbursts, sleep
difficulties, and appetite decrease) that the medical therapy requires discontinuation (Wigal et al., 2006). Lastly, the long-term effects of medications for ADHD are unknown (Vitiello, 2004). Therefore, there is a need for effective psychosocial interventions for adults with ADHD that can be offered complementary or instead of pharmacotherapy (Solanto, Marks, Mitchell, Wasserstein, & Kofman, 2008).
A plausible psychosocial approach for treating adult ADHD is mindfulness (Mitchell et al., 2013). Mindfulness involves the self-regulation of attention by curiosity, openness and acceptance that can be cultivated through meditation (Bishop et al., 2004). It is defined as ‘the awareness that emerges through paying attention on purpose, in the present moment, and nonjudgmentally to the unfolding of experience moment by moment’ (Kabat-Zinn, 2003, p. 145). Mindfulness has been related to reductions in impulsive behaviour (Peters, Erisman, Upton, Baer, & Roemer, 2011) and increased emotion regulation in healthy adults (Robins, Keng, Ekblad, & Brantley, 2012), both constituting aspects of ADHD (Reimherr et al., 2005, Barkley & Fischer, 2010).
Several studies have indeed provided preliminary evidence for the efficacy of mindfulness in adult ADHD. These studies found significant improvements in ADHD self-reported symptoms and executive functioning after mindfulness training in an adult sample (Zylowska et al., 2008; Mitchell et al., 2013). Zylowska et al. (2008) and Mitchell et al. (2013) both adapted the clinical model of mindfulness training to meet the needs of adults with ADHD, including psychoeducation for ADHD and shorter meditation periods. Hepark, Kan and Speckens (in press) assessed the feasibility and effectiveness of a mindfulness program in a Dutch population (N = 11). The results indicated an improvement in self-reported ADHD symptoms and executive
functioning. They also found a tendency towards an improvement in anxiety and acting with awareness, which refers to ‘attending to one’s activities of the present moment opposed to behaving automatically while attention is focused elsewhere’ (Baer, 2009, p. 16). However, a limitation of the studies was the small sample size. As such, a larger comparative study is required to increase precision of the treatment efficacy.
Schoenberg et al. (2013) initiated a randomized controlled trial to assess the effect of an extensive mindfulness protocol in ADHD patients as compared to a
waitlist control group. In this study, a regular mindfulness protocol was combined with a psychoeducation module (MBCT+). Inclusion was completed at 96 patients, but only part of the data (50 patients) have been analysed to address a different research
question pertaining to the association between ADHD symptoms and neurophysiological changes after Mindfulness.
In this study, our first aim is to address the initially proposed study question: the effect of mindfulness training with a psychoeducation module on ADHD symptoms (MBCT+). We used the complete data provided by Schoenberg et al. (study 1) to
answer this research question. However, due to the emphasis on psychoeducation in their treatment protocol, inferences on the “pure” effect of Mindfulness on ADHD symptoms cannot be made. Therefore, our second aim is to determine the acceptability of a stand-alone mindfulness protocol (MBCT) for an ADHD population, in order to examine if it is feasible to develop a clinical trial comparing a stand-alone Mindfulness program with treatment as usual in improving ADHD symptoms. With this goal, a pilot study was conducted (study 2), consisting of a regular mindfulness course including approximately 12 participants. The pilot study was based on the established protocol Mindfulness Based Cognitive Therapy (MBCT), originally developed for patients suffering from depression (Segal, Williams, & Teasdale, 2002). Given that MBCT included cognitive components targeting depression symptoms, the protocol was adapted for an adult ADHD population.
We conducted both quantitative and qualitative explorative analyses in study 2. Qualitative analyses are especially convenient for studying specific treatment
components, allowing revisions of the Mindfulness treatment manual (Hertenstein et al., 2012). Specifically, a focus group was organised: a group discussion to explore people’s subjective views and experiences with MBCT (Kitzinger, 1994). We did not take into account quantitative results in our decision to proceed with the actual RCT, given that lack of power due to the small sample size would increase the chance of falsely reporting nonsignificant results (Bates, Dufek, & Davis, 1992), and in turn lead to erroneously decide not to continue with the RCT.
Our third aim is to study the possible mechanisms through which mindfulness training might exert characteristic effects. One of the fundamental features of
mindfulness is self-compassion (Kuyken et al., 2010). That is, mindful awareness can only enable a fundamental shift in awareness or attention when friendliness and compassion are integrated in the present-moment experience we are attending to (Segal, Williams, & Teasdale, 2013). Self-compassion is developed through the emphasis on kindness and self-care in all mindfulness practices. The cultivation of self-compassion might be especially important for individuals with ADHD, since ADHD has been associated with less self-acceptance compared to individuals without ADHD (Newark & Stieglitz, 2010). An increase in mindfulness is associated with an increase in self-compassion (Birnie, Speca, & Carlson, 2010). We therefore suggested that the practice in mindfulness might increase self-compassion, and consequently improve ADHD symptoms.
Given the research providing evidence for the efficacy of an adapted mindfulness protocol for ADHD (Zylowska et al, 2008; Mitchell et al, 2013), the first hypothesis was that MBCT+ is effective in decreasing self-, and investigator-reported ADHD symptoms compared to a waitlist control group. Given the association between ADHD symptoms and EF (Willcut et al., 2005), we also expected a decrease in impairments of EF. Since a core component of “pure” mindfulness is the regulation of attention, and stand-alone mindfulness is effective in reducing impulsive behavior (Bishop et al., 2004; Peters, Erisman, Upton, Baer, & Roemer, 2011), the second hypothesis was that MBCT is an acceptable, and feasible treatment for adult ADHD. Lastly, we
hypothesized that self-compassion may play an essential role in mediating the relationship between Mindfulness and ADHD.
Study 1: effect of MBCT+ on adult ADHD
MethodParticipants
The sample was composed of 103 adult ADHD patients aged 18-65 receiving
treatment for ADHD via Radboud University Nijmegen Medical Centre outpatient unit of the department of Psychiatry (see table 1 for a summary). 55 patients were randomly allocated to the treatment condition (MBCT+) and 48 to the waitlist control condition. Not all patients completed the pre- or post questionnaires. Patients who completed the intervention did also complete the outcome questionnaires. Patients who did not complete the intervention (attended to 6 sessions or less) did not complete the post questionnaires either. Depending on the outcome questionnaires, there was a response rate varying between 24.1 % and 68.5 % in the MBCT+ group, and between 31.3 % and 77.1 % in the Waitlist group. Since the ADHD observer questionnaire (CAARS-Ob) had a particularly low response rate (24.1 % and 31.3 % in the MBCT and Waitlist group respectively), we did not include this questionnaire in the further analyses. Further measures showed response rates above 50%. Given the overall low response rate, our resulting sample size is too small to achieve an appropriate power of .80. The results should therefore be interpreted with caution.
Inclusion criteria were a primary diagnosis of ADHD according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV, American Psychiatric
Association, 2000). All types of ADHD were included in the study (inattentive subtype, hyperactive-impulsive subtype and a combined subtype). Exclusion criteria were substance abuse/dependence within the last 6 months, co-morbid psychotic-, borderline-, antisocial-, and behavioral disorders, and learning difficulties. Stimulant medication dosage was stabilized two weeks and non-stimulant medication 4 weeks prior to participation. Of the 103 participants, 59 [33 (55.9%) MBCT+; 26 (44.1%) Waitlist] received ADHD medication, leaving 44 [22 (50.0%) MBCT+; 22 (50.0%) Waitlist] participants not receiving medication. From the 59 participants receiving ADHD medication, 42 took methylphenidate-based medication [25 (59.5%) MBCT+; 17 (40.5%) Waitlist], 12 dextroamphetamine-based medication [5 (41.7%) MBCT+; 7 (58.3%) Waitlist], 4 participants were taking bupropion (an antidepressant sometimes prescribed off-label for ADHD) [3 (75%) MBCT+, 1 (25%) Waitlist)] and 1
participant in the Waitlist group was taking atomoxetine. We did not take into account the use of other psychopharmaca and medications since we did not expect a substantial effect of other medications on the effectiveness of MBCT+.
Measures
Screening and diagnostic measures. The Dutch instrument Diagnostisch Interview voor ADHD bij volwassenen (DIVA 2.0; Kooij & Francken, 2010) was used as
screening measure. The DIVA is a semi-structured interview based on the DSM-IV criteria of ADHD. The interview consists of 23 items assessing the presence of attention deficit, hyperactive-impulsive symptoms, and overall dysfunction due to ADHD symptoms in both childhood and adulthood (Kooij & francken, 2010). There is no information available concerning its validity and reliability.
Treatment outcome
ADHD measures
ADHD symptoms were assessed with the self-report and investigator rating versions of the Conners Adult ADHD Rating Scale (CAARS-S, CAARS-IN Adler et al., 2007). The CAARS-S consists of 30 items, which are rated on a 4-point Likert scale. It has shown good internal consistency (Cronbach’s alpha) for both the investigator and self-ratings (.88 and .90 respectively). The interrater reliability (Cohen’s alpha) between
investigator ratings and self-ratings ranged from .62 to .67 across the different CAARS scales. CAARS-IN was employed as primary outcome measure, since CAARS-IN scores have proven stronger predictors of treatment outcome than self-report scores (Adler et al., 2007). The CAARS-IN is assessed blindly. It should be noted that there is no information available concerning the psychometric properties of the CAARS-IN and CAARS-S for a Dutch population.
Secondary outcome measures
Patient functioning was measured with the Dutch version of the Outcome
Questionnaire (OQ; Lambert, Finch, & Maruish, 1999). The OQ consists of 45 items, which are scored on a 5-point Likert scale. The OQ is a multitrait scale consisting of three subscales: Subjective Distress, Interpersonal Relations and Social Role.
According to research, the OQ has good psychometric properties, including an adequate test-retest reliability (.84) and excellent internal consistency (.93)
(Vermeersch, Lambert, & Burlingname, 2000). The psychometric properties of the Dutch version are similar to the original version of the OQ (de Jong et al., 2007).
Executive functioning was assessed with the Behavior Rating Inventory of Executive Function- Adult Self Report Version (BRIEF-A; Roth, Isquith, & Gioia, 2005). The BRIEF consists of 75 items and nine scales: inhibition, shifting, emotional control, self-monitoring, initiation, working memory, planning/organizing, task monitoring, and organising of materials. It includes three validity scales: negativity, infrequency and inconsistency (Roth, Isquith, & Gioia, 2005). The Dutch version of the BRIEF has sufficient reliability (.77); nevertheless it lacks construct validity and criterion validity (Egberink, Vermeulen, & Frima, 2009-2014). However, we have chosen this instrument because it has shown a good utility in measuring problems in executive functioning across clinical and non-clinical populations (Roth et al., 2013).
Mindfulness skills were assessed with the Dutch translation of the Kentucky Inventory of Mindfulness Skills (KIMS; Baer, Smith, & Allen, 2004). The KIMS is a self-report inventory consisting of four mindfulness skills: observing, describing, acting with awareness, and acceptance without judgement. The KIMS has good
internal consistency (Cronbach’s alpha >.80) and test-retest reliability (.65, .81, .86 and .83 for Observe, Describe, Act with Awareness, and Accept Without Jugdment
respectively). Nevertheless, the psychometric properties of the Dutch version are unknown.
Beck Depression Inventory (BDI; Beck, Steer, & Garbin, 1988) was used to assess the possible presence of depression symptoms. The BDI is self-administered and contains 21 items. The BDI has shown strong concurrent validity ( >.60) and test-retest reliability (>.60) (Beck, Steer, & Garbin, 1988).
In order to measure levels of state and trait anxiety, the Dutch version of the State-Trait Anxiety Inventory was administered (STAI). The STAI consists of 20-item self-report statements describing how people feel at a particular moment (state) and 20 items with a description of general feelings of anxiety (trait). The English version of the STAI shows positive psychometric features, with good test-retest reliability (> .70) and excellent internal consistency ( >.89) (Barnes, Harp, & Sik Jung, 2002). The Dutch version shows similar psychometric properties.
Procedures
Each participant was asked informed consent to participate in a controlled randomised study before starting with the intervention. Clinical measures for the MBCT+ group were assessed prior to the first MBCT+ session and after the last session. For the WL group, the measures were assessed with a time interval of 12 weeks, preceding the start of their own MBCT+ course. The WL group continued with their current treatment, which consisted mostly of psychoeducation and/or pharmacological treatment. Randomisation was conducted before the first data collection.
Intervention
The MBCT+ training was adapted from the original Mindfulness protocol developed for depressive disorders (Segal, Williams, & Teasdale, 2002). The programs differed from each other in the following aspects:
1. The current MBCT+ training consisted of 11 weekly group sessions that lasted 3 hours each instead of 8 weekly group sessions of 2.5 hours.
2. The original protocol applied a silence day of 6 hours, but this was replaced by a silent morning of 3 hours between session 10 and 11 in the current training. 3. Psycho-education for depression in the original protocol was replaced by more
application of methods in order to integrate mindfulness in daily life and II) the neurobiology of ADHD and the neural mechanisms of mindfulness and III) education about recognition and coping with clinical symptoms of ADHD. 4. One session of the current MBCT+ program was aimed at mindful listening and
speaking, not present in the regular program.
Participants received workbooks and CDs to guide the exercises, requiring
approximately 15-45 min of self-practice each day, build up gradually over time. The practitioner stimulated the maintenance of self-practice. Experienced mindfulness practitioners administered the course.
Statistical analysis
Data analysis.
A completers analysis was conducted through a repeated-measures mixed-design ANOVA. Group status (MBCT+, waitlist) was entered as the between-subjects factor and time (baseline assessment, 12-week assessment) as the within-group subjects factor. An interaction effect would show a significant improvement in the treatment group for the dependent variables, compared to the waitlist group.
To explore whether a change in Mindfulness skills (partly) explained the effect of group status on ADHD difference scores, a mediation analysis was conducted, following the assumptions proposed by Baron and Kenny (1986). The CAARS-IN difference score was entered as the dependent variable, given that investigator ratings have proven to be stronger predictors of treatment outcome compared to self-report ratings (Adler et al., 2007). The difference score on the KIMS figured as the
independent variable. The model with the mediator was compared with the model without the mediator to investigate (partial) mediation effects. A bootstrap of 1000 replications was employed. Exploratively, we looked at the mediation effect of
Mindfulness skills in the relationship between group status and Executive Functioning. The mediation analyses were conducted with the PROCESS macro, template number 4, developed by Andrew F. Hayes available on his website:
http://www.afhayes.com/spss-sas-and-mplus-macros-and-code.html. SPSS package 20.0.0 was used for the analyses.
Results
Participant baseline characteristics. There were no significant differences in
participant baseline characteristics between the MBCT group and Waitlist group (see table 1).
Feasibility. Regarding drop-out rate, 18 of 55 participants randomized to the treatment
group did not complete the study (32.7%), whereas 11 of 48 (22.9%) participants randomized to the Waitlist group did not complete the study (based on the CAARS-Self report). Study completion was defined as having attended to at least 6 sessions. Participants who dropped out were not assessed at post-treatment. Therefore, only pre-post measures from completers were available. The difference between drop-out rate in the treatment group and waitlist group was not significant, Χ2 (1) = 1.22, p = ,269. Completers in the MBCT+ group were significantly older than non-completers (see table 3).
ADHD symptoms. Interaction-effects for group x time for both the self-reported and
clinician ratings of inattentive ADHD symptoms were significant (F (1) = 6.2 p = .015 and F (1) = 8.9 p = .004 respectively) (see table 2). These results indicate an
improvement in symptoms between pre- and post assessment for the treatment
condition compared to the waitlist condition. The interaction-effect for goup x time for the investigator rated hyperactive-impulsive symptoms was significant, F (1) = 12.6, p = .001, however self-reported hyperactive-impulsive symptoms was not significant, F (1) = 3.3, p = .073, suggesting that clinicians perceived more improvements in
hyperactive-impulsive symptoms contrary to the participants. Exporatively, we
investigated whether patients and investigators reported different ratings of inattention and hyperactivity/impulsivity at pre- and post- assessment. The results indicated that patients underreported inattention symptoms at baseline compared to investigators, t(84) = -2.23, p = .029, but no significant difference was found between baseline self-reported hyperactive-impulsive symptoms and investigator ratings.
Quality of life. No significant group x time interaction effect was found for quality of
life, suggesting no improvements in distress, interpersonal relations, or social roles over time in the treatment group relative to the waitlist group (see table 2).
Executive Functioning. According to the BRIEF-ASR, group x time interaction was
highly significant, F (1) = 18.3 p = .0001, showing significant group x time effects on all subscales, suggesting an improvement of overall executive functioning over time compared to the waitlist group (see table 2).
Depression and anxiety. No significant group x time effects were found for scores on
depression and anxiety. Nevertheless, this result is congruent with other studies (Philippot et al., 2012). It should also be noted that a decrease in depression and anxiety was not the primary outcome of the current study.
Mediation effects. Mindfulness skills were expected to have a mediating effect on the
relationship between group allocation and the ADHD difference scores measured with the CAARS-Investigator. Mindfulness skills were related to condition, [β = 11.18, t(SE = 4.05) = 2.76, p < .01], 95% CI 3.07 to 19.29, suggesting that participants in the MBCT group showed increased mindfulness skills compared to the waitlist group (see figure 5). ADHD difference scores were also related to mindfulness skills, [β = -0.21, t(SE = 0.06) = -3.61, p< .01], 95% CI -0.33 to -0.09, indicating that an improvement in mindfulness skills was associated with a decrease in ADHD symptoms, according to the investigator ratings. The relationship between condition and ADHD difference scores, without a mediator, yielded β = 6.08, t(SE = 2.0) = 3.09, p< 001, 95% CI -10.02 to -2.14.
Adding mindfulness skills as a mediator between group allocation and ADHD difference scores showed a full mediation effect, meaning a smaller β and a non significant p value compared to the model without the mediator: β = -3.73, t(SE = 1.91) = -1.96, p = .06, CI -7.55 to 0.09. We bootstrapped the indirect effect of
condition on ADHD difference scores with 1000 samples, which showed a significant indirect effect for mindfulness skills: point estimate = -2.35, 95% CI -5.33 to -0.53.
Given that group allocation had a highly significant effect on the BRIEF-ASR, and the BRIEF-ASR shows a considerable overlap with the CAARS, a possible
mediating effect of Mindfulness skills on the relationship between group allocation and Executive functioning was investigated (see figure 5). For this, the difference between pre- and post scores on the BRIEF-ASR was entered as dependent variable.
Mindfulness skills was related to condition, β = 13.55, t(SE = 3.79) = 3.57, p < .001, 95% CI
5.96 to 21.14, indicating that participants in the MBCT+ group showed increased Mindfulness skills relative to the waitlist group. The relationship between condition and BRIEF-ASR difference scores, without a mediator, yielded β = -34.92, t(SE = 8.42) = -4.15, p< .001, 95% CI -51.78 to -18.07. Adding mindfulness skills as a
mediator between group allocation and BRIEF-ASR difference scores showed a partial mediating effect, meaning a smaller β and a smaller but significant p value, compared to the model without the mediator: β = 20.96, t(SE = 8.3) = 2.52, p < .05, 95% CI -37.57 to -4.34. The indirect effect of condition on BRIEF-ASR difference scores was bootstrapped with 1000 samples, and showed a significant indirect effect of
mindfulness skills: point estimate = -0.38, 95% CI -32.17 to -5.39.
Moderation effects. There was no moderating effect of medication status, gender, and
age, indicating an absence of influence of these factors on the effect of MBCT on ADHD symptoms.
Table 1. Participant Baseline Characteristics for MBCT+ (n = 55) and Waitlist (n = 48)
MBCT+ Waitlist Test statistic p value
Age (SD) 36.45 (10.37) 35.17 (9.34) t(101) = -0.658 .512
Sex (%) Χ2 (1) = 2.640 .104
Males 21 (38.2%) 26(54.2%)
Females 34 (61.8%) 22 (45.8%)
ADHD medication status (%) Χ2 (1) = .356 .550
Yes 33 (60.0%) 26 (54.2%)
No
Baseline:
STAI (SD) BDI (SD)
CAARS-Self report total CAARS-Investigator total OQ-42.5 total KIMS total BRIEF-ASR total 22 (40.0%) 90.27(19,61) 13.0(9.39) 28.31(7.52) 29.27(9.38) 67.33(19.83) 72.53(17.09) 150.14(24.20) 22 (45.8%) 96.4(17,9) 13.4(8.07) 29.60(7.99) 29.60(7.52) 68.47(17.81) 70.81(14.47) 155.58(17.60) t(93) = 1.57 t(93) = .243 t(94) = .867 t(87) = .183 t(93) = .291 t(93) = -.524 t(90) = 1.217 .120 .809 .388 .855 .771 .601 .217
Table 2. Measurement results MBCT+ and Waitlist1
MBCT+ (n= 37) Waitlist (n = 37)
Pre Post Pre Post
M (SD) M (SD) M (SD) M (SD) Group x time effect
CAARS- Self report
P value Inattention 15.4(3.9) 12.8(4,2) 16.6(4,5) 16.1(3.8) .015 * Hyperactive-impulsive 12.8(4.8) 10.3(4.2) 13.6(4,5) 12.6(5.0) .073 ADHD (total) 28.2(7.0) 23.0(7.3) 30.2(6.5) 28.8(6.9) .014 * CAARS- Investigator Inattention 16.3(4.7) 12.4(4.6) 17.0(4.5) 16.5(4.2) .004** Hyperactive-impulse 13.0(5.6) 9.0(4.6) 12.0(4.8) 11.5(5.3) .001** ADHD (total) 29.3(8.7) 21.5(7.7) 29.0(7.1) 28.0(7.5) < .0001 *** OQ-42.5 Symptom Distress 38.9(13.0) 34.4(12.5) 39.4(11.9) 38.5(16.0) .157 Interpersonal Relations 14.8(5.1) 13.5(5.9) 15.9(5.1) 15.0(6.7) .709 Social Roles 12.6(3.6) 12.3(3.9) 13.8(3.8) 13.1(4.4) .608 Global score 66.3(17.8) 60.2(19.8) 69.1(17.5) 66.6(24.0) .345 KIMS Observe 20.86(8.4) 24.3(7.2) 19.1(6.2) 19.2(6.9) .037* Describe 18.2(6.1) 19.5(5.3) 17.9(5.5) 19.1(6.5) .863 Act-with-awareness 12.9(4.6) 17.3(5.9) 12.5(5.2) 12.5(5.2) .002** Accept-without judgment 20.0(6.5) 22.2(6.6) 19.5(7.3) 19.5(7.7) .177 Total 72.0(14.7) 83.3(17.1) 69.0(12.4) 70.2(12.7) .006**
1 Number of completers varied across questionnaires, n = 37 is based on the average number of completers.
BRIEF-ASR Inhibition 17.2(3.3) 14.7(3.1) 18.2(2.6) 17.4(3.2) .006** Self 12.2(3.0) 9.8(2.5) 12.4(3.2) 11.6(2.7) .017* Init 15.9(3.9) 14.3(3.9) 17.0(2.0) 17.9(2.6) .031* Work 18.1(2.8) 16.6(3.4) 17.0(2.7) 19.3(2.5) .019* Plan 22.4(3.8) 18.8(4.1) 22.7(3.1) 23.9(3.2) .002** Task 12.8(2.2) 10.8(2.6) 12.4(2.3) 13.2(3.0) .009** Orga 17.6(4.3) 13.9(4.2) 17.8(3.3) 18.4(4.3) < .0001 *** Shifting Emot 12.6(2.9) 19.5 (5.12) 11.1(3.0) 17.08 (4.7) 12.5(2.7) 18.8 (4.9) 12.3(3.0) 18.78 (4.9) .008** .008** Total 152.1(21.9) 132.2(26.4) 156.0(16.6) 153.8(18.8) < .0001*** STAI State 41.5(9.5) 36.5(11.5) 46.9(9.7) 43.3(14.1) .570 Trait 47.5(9.9) 42.0(11.6) 50.2(10.4) 47.6(12.3) .168 Total 89.0(18.0) 78.5(22.0) 97.2(18.5) 90.8(25.6) .293 BDI Total 12.1(8.7) 9.1(7.8) 13.2(8.3) 11.8(9.8) .306
Table 3. Participant Baseline Characteristics for non-completers (n = 18) and completers (n = 37)
in the MBCT+ group2
Non-completers Completers Test statistic p value
Age (SD) 32.2(9.8) 38.5(10.1) t(53) = -2.2 .033*
Sex (%) Χ2 (1) = 1.227 .268
Males 5 (27.8%) 16(43.2%)
Females 13(72.2%) 21(56.8%)
ADHD medication status (%) Χ2 (1) = 1.16 .283
Yes 12(66.7%) 19(51.4%)
No 6(33.3%) 18(48.6%)
Table 4. Participant Baseline Characteristics for non-completers (n = 11) and completers (n = 37)
in the Waitlist group3
Non-completers Completers Test statistic p value
Age (SD) 34.8(8.6) 35.3(9.7) t(46) = -.139 .890
Sex (%) Χ2 (1) = 515 .473
Males 7(63.6%) 19(51.4%)
Females 4(36.4%) 18(48.6%)
ADHD medication status (%) Χ2 (1) = .436 .509
Yes 5(45.5%) 21(56.8%)
No 6(54.5%) 16(43.2%)
2 Based on CAARS-SV 3 Based on CAARS-SV
Figure 5. Mediation and non-mediation analyses with ADHD symptoms (a) and EF (b) as
Discussion study 1
To our knowledge, study 1 is the first randomized controlled trial assessing the preliminary efficacy of Mindfulness training for adult ADHD on core symptoms, executive functioning, and quality of life. This investigation builds further on former research on mindfulness for ADHD, using a large sample size, and including a waitlist group.
Concerning ADHD symptoms, both self-report and investigator scores indicated improvements in ADHD symptoms in the treatment group compared to the waitlist group. Specifically, self-report ratings suggested a decrease in inattention but not in impulsive-hyperactive symptoms, whereas investigator ratings indicated a decrease in both inattention and hyperactive-impulsive symptoms. Moreover, patients underreported attention symptoms at baseline compared to investigators. This is in line with research reporting different severity levels of ADHD according to informants and patients (Kooij, Boonstra, Swinkels, Bekker, de Noord, & Buitelaar, 2008).
A significant effect of MBCT+ on overall executive functioning was found. This is in accordance with prior research concerning the effect of mindfulness on EF self-reported symptoms (Mitchell et al., 2013) and on neurocognitive tests, such as conflict attention and set-shifting (Zylowska et al., 2008). Mitchell et al. (2013) did however not find an effect on EF lab task tests, so it should be questioned whether there are differences between self-reported ADHD symptoms and executive functioning measured in other settings.
It should be noticed that the mindfulness training provided by Mitchell et al. (2013) and Zylowska et al. (2008) consisted of 20 hours of training in total, whereas this training consisted of 36 hours. Therefore it is not clear whether the similarities in findings are due to treatment components or training content and duration. An
alternative explanation may be that extra mindfulness sessions and the extensive psychoeducation component may have contributed to larger effects. Therefore, study 2 went into further detail on the effect of stand-alone mindfulness training (without psychoeducation) for adult ADHD.
Regarding working mechanisms of mindfulness, there was a full mediating effect of mindfulness skills, suggesting that mindfulness exerts its characteristic effects through an increase in mindfulness skills, and consequently an improvement in ADHD
symptoms. We also found a partial mediating effect of mindfulness skills on the relationship between MBCT and executive functioning.
Contrary to our expectations, MBCT did not have an effect on quality of life. A possible explanation is that this intervention explicitly targeted ADHD symptoms and focused less on the effects of ADHD on related functional impairments in daily life. It may take more time to generalize improvements in ADHD symptoms to overall patient functioning. Future research could include a follow up to investigate whether an
improvement in mindfulness skills has a delayed effect on quality of life. It would therefore be adequate to incorporate booster sessions after the mindfulness course, in order to ensure adherence to mindfulness practice.
The current investigation presents some drawbacks that should be pointed out. First, no complete outcome data was available for all randomized subjects, which led to a smaller sample size than initially proposed, not ensuring sufficient statistical power. Second, all data were from participants who completed the mindfulness training. The results therefore only reflect the effect of MBCT+ when all patients adhere to the assigned MBCT+ condition, and cannot be interpreted in the light of benefits for the community, given that in real life there inevitably is treatment non-adherence (Ten Have, Normand, Marcus, Brown, Lavori, & Duan, 2008). Overall, future research may take into account a large dropout rate when working with an ADHD population. In order to motivate participants, different strategies could be employed, such as sms alerts, use of digital questionnaires (which can be answered on different time-points), and contacting participants in case of no show. In this way, less information will get lost and it would be possible to get a more representative insight in the effects of MBCT+ on adult ADHD.
Concerning informant ratings, the CAARS-Observer was assessed in a small sample of participants, and was therefore not analysed. Future research may focus more on targeting informants, since they could provide valuable information with regard to patient functioning.
The current research did not take into account comorbidity, despite the considerable amount of literature documenting the association between ADHD and other disorders, such as mood disorders, anxiety disorders, and drug dependence (Kessler et al., 2006). Future research could investigate the possible differential influence (moderation) of comorbid disorders on treatment effectiveness.
To conclude, study 1 provided support for the treatment effectiveness of an adapted mindfulness training (MBCT+) for adult ADHD. However, the effect of stand-alone mindfulness remained unclear. Therefore, study 2 aimed at assessing the
feasibility and acceptability of an original mindfulness protocol (MBCT), in order to study whether stand-alone and shorter mindfulness training may be implemented for an adult ADHD population.
Study 2: Feasibility and acceptability of stand-alone MBCT for adult
ADHD: a pilot study
This study was aimed at investigating the feasibility and acceptability of an original MBCT protocol among a Dutch adult ADHD population in order to investigate whether a clinical trial in the future could be justified.
Method
Participants
The treatment group was composed of 11 ADHD patients aged 16-65 receiving
treatment for ADHD via Radboud University Nijmegen Medical Centre outpatient unit of the department of Psychiatry. This group was compared to the waitlist control group of the first study (MBCT+ training for ADHD), consisting of 48 participants. Of the 11 participants, one participant did not continue the training after the first session, due to unpleasant associations with the training location. Two participants only completed 4 sessions, because of physical health problems in one case, and personal difficulties in the other case. Not all participants completed pre- or post questionnaires. Specifically, 9 participants in the treatment group completed all questionnaires. One participant dropped out, and one did only complete part of the post- questionnaire. One of the participants filled in the post-questionnaire twice; therefore we randomly selected one of the two questionnaires for the analysis. In the waitlist group, 11 of the 48 (22.9%) participants did not complete pre- or post assessments.
Inclusion criteria were a primary diagnosis of ADHD according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV, American Psychiatric
All types of ADHD were included in the study (inattentive subtype, hyperactive-impulsive subtype and a combined subtype). Exclusion criteria were substance
abuse/dependence within the last 6 months, co-morbid psychotic-, borderline-, antisocial-, and behavioral disorders, and learning difficulties. Stabilization of stimulant medication dosage was not required, opposed to the former trial. Of the 11 participants, 3 (27.3%) were not taking any medication. From the 8 participants receiving ADHD medication, 6 (54.5%) took methylphenidate-based medication, 1 participant was taking atomoxetine (9.1%) and 1 (9.1%) participant was taking bupropion (an anti-depressant sometimes prescribed off-label for ADHD). During the intervention, 3 (27.3%) participants changed their medication type or dosage, 7
participants remained stable on their medication (63.6%), and of 1 (9.1%) participant it was unknown whether there had been a medication change. We did not take into account other psychopharmaca or medications.
Mindfulness training
We used a protocol based on Mindfulness Based Cognitive Therapy (MBCT), an established mindfulness intervention as originally developed for depressive disorders (Segal, Williams, & Teasdale, 2002). The training consisted of 8 weekly group sessions for 2.5 hours, and a silent half day retreat after session 6. A silent day is held in complete silence and incorporates the different mindfulness techniques that have been practiced during the course. Since the original MBCT program includes psychoeducation for depression, this training also consisted of psychoeducation for ADHD instead of depression, but to a much lesser extent than the first study. Just like the first study, participants received workbooks and CDs. Experienced mindfulness practitioners administered the course and stimulated participants to continue practicing during the course.
Quantitative measures
Screening and diagnostic measures. The Dutch Diagnostisch Interview voor ADHD bij volwassenen (DIVA; Kooij & Francken, 2010) was used as screening measure. See
Treatment outcome. Response to treatment was assessed through self-report rating
scales completed at the centre for Mindfulness, and via online questionnaires.
Primary outcome measure
- ADHD symptoms were assessed with the self-report rating version of the
Conners Adult ADHD Rating Scale (CAARS-S; Adler et al., 2007). See study 1 for a full description of the instrument.
Secondary outcome measures.
- Quality of life was measured with the Dutch version of the Outcome
Questionnaire (OQ 42.5; Lambert, Finch, & Maruish, 1999). See study 1 for a full description of the instrument.
- Executive functioning was assessed with the Behavior Rating Inventory of
Executive Function- Adult Self Report Version (BRIEF-A; Roth, Isquith, & Gioia, 2005). See study 1 for a full description of the instrument.
- Health and well-being were assessed with the 12-item Short-Form Health Survey
(SF-12; Ware, Kosinski, & Keller, 1995). This is a self-rating instrument that contains 12 items across the following dimensions: health, physical functioning, physical role limitation, mental role limitation, social functioning and mental health and pain. The SF-12 has shown to have good psychometric properties (reliability: .89, validity: .93) (Gandhi et al., 2001). The SF-12 has demonstrated discriminative validity in a Dutch population (Mols, Pelle, & Kupper, 2009).
- Mindfulness skills were assessed with the Five Facet Mindfulness Questionnaire
(FFMQ; Bohlmeijer et al., 2011). This is a self-report inventory, which specifies five Mindfulness skills: observing, describing, acting with awareness, non-judging, and nonreactivity. It consists of 39 items that are rated on a 5-point Likert scale. The FFMQ has demonstrated to be a reliable (>.7) and construct valid measure (showing high correlations with theoretically related constructs) in assessing Mindfulness in people with depressive symptoms (Bohlmeijer et al., 2011).
- compassion was measured with the 12-item short-form version of the
scale consists of six components: self-kindness, self-judgment, common
humanity, isolation, mindfulness and over-identification. The SCS-SF has good reliability (Cronbach’s alpha > .86) and validity (r > .97) (Raes et al., 2011). However, it should be noted that there is no information available on the psychometric properties of the Dutch version of the SCS-SF.
Procedure quantitative analysis
Each participant was asked oral informed consent to participate in the pilot study. Clinical measures for the MBCT group were assessed prior to the first MBCT session and after the last session. The waitlist group of the first study was used as a control group.
Data analysis.
Initially, we wanted to conduct an intention to treat analysis, whereby participants completing less than 4 sessions were considered dropouts. However, since only one participant who attained less than 4 sessions did not want to complete the post
assessment, all of the post assessments were from completers. Therefore, a completers analysis was conducted through a repeated-measures mixed-design ANOVA. Group status (MBCT, waitlist) was entered as the between-subject factor and time (baseline assessment, 9-week assessment) as the within-group subject factor.
Some questionnaires were only used in the MBCT group and not in the waitlist group. Differences between pre- and post scores on these questionnaires were therefore analysed with a dependent t-test.
Qualitative measures
Evaluation form
Participants responded to an evaluation questionnaire in order to assess the feasibility and acceptability of the mindfulness training. This questionnaire was adapted from other evaluation forms aimed at assessing the feasibility of mindfulness for cancer patients, developed by researchers at the Radboud centre for mindfulness. Participants indicated their overall satisfaction level with the different training components on a
rating scale of 1 (don’t agree at all) to 5 (fully agree). Other items concerned satisfaction with treatment duration and group size. Some items were developed to specifically assess satisfaction with ADHD components in the training, such as sharing of information with other ADHD participants, and the extent of focus on
psychoeducation. Participants also had the possibility to answer open questions concerning positive and negative aspects of the training and the trainers. Moreover, trainers monitored treatment adherence and attrition to assess feasibility.
Focus interviews
This part of the study aimed to qualitatively assess the feasibility and acceptability of an original MBCT protocol for adult ADHD. Particularly, we investigated I) helpful and limiting aspects of the course, II) possible adaptations to the program, III) changes in ADHD symptoms and wellbeing, and IV) changes in attitudes towards the mental and physical ‘self’. Two focus groups were conducted: one consisting of 4 participants and the second one of 3 participants. The interviewer was guided by a list of topics, based on literature highlighting difficulties that adults with ADHD may encounter when practicing Mindfulness.
The following questions were asked:
1) Did you experience any difficulties due to ADHD symptoms? 2) What would you like to change in the MBCT program? 3) Which aspects were considered helpful of the program?
4) Did you experience any changes during or after the MBCT course?
5) Did you notice any changes in attitude towards yourself during or after the MBCT course?
Procedure qualitative study
The focus groups lasted approximately 90 minutes. The focus interviews were conducted at the Mindfulness Centre by an experienced and independent researcher. Interviews were recorded and transcribed verbatim. After the first focus interview, questions were adapted for the second interview, in order to follow on the issues raised by the participants. Verbatim transcripts were independently coded by two
investigators into subcategories, and then grouped in core categories that pertained to one of two formerly established themes: Feasibility (F) or Process (P).
Data analysis.
Analysis of the qualitative study was conducted with the qualitative analysis program ATLAS.ti.
Results: quantitative analysis 4
Participant baseline characteristics. Significant differences between baseline
assessment scores on the CAARS-SV and OQ-42.5 were found, indicating that participants in the pilot group showed significantly more ADHD symptoms and experienced significantly more difficulties in general quality of life relative to the waitlist group at baseline (table 1).
ADHD symptoms. We found a significant group x time effect of MBCT on ADHD
symptoms, F (1) = 11.14, p = .002, indicating that participants in the pilot group improved significantly more on their symptoms than participants in the waitlist condition (see table 2). Specifically, there was a significant improvement in hyperactive-impulsive symptoms, F (1) = 15.46, p < .0001, but not on inattention symptoms, F (1) = 2.76, p = .104 (see table 2).
Quality of life. There was no group x time effect of MBCT on quality of life, relative to
the waitlist group (see table 2).
Executive Functioning. No group x time effect was found of MBCT on Executive
functioning compared to the waitlist group, indicating no significant improvement in Executive functioning due to the MBCT training (see table 2).
In the pilot study, some other instruments were employed, only allowing for pre- post assessments.
4 These results should be interpreted with caution given the small number of participants.
Mindfulness. There was no change of mindfulness skills between pre- to post
assessment, as measured with the FFMQ (see table 3).
Self-compassion. No significant change of self-compassion across time was found,
measured with the SCS (see table 4). However, self-compassion assessed on 6 different time points showed a trend in increase from week 1 to week 5, and after week 5 a decrease (see figure 4).
Health- and well-being. There was no change in health- and well-being from pre- to
post assessment, measured with the SF-12. (see table 3).
Table 1. Participant Baseline Characteristics for MBCT (n = 11) and Waitlist (n = 48)
MBCT Waitlist Test statistic p value
Age (SD) 33.0(14.0) 35.2(9.3) t(12.1) = 0.6 0.63
Sex (%)
Males 4(36.4) 26(54.2) Χ2 (1) = 1.1 0.29
Females 7(63.6) 22(45.8)
ADHD medication status (%)
Yes 8(72.7%) 26(54.2) Χ2 (1) = 1.3 0.26
No
Baseline:
CAARS-SV total OQ-42.5 Global score BRIEF-ASR total 3(27.3%) 48.36(4.4) 116.9(17.3) 143.27(20.6) 22(45.8) 29.60(7.0) 68.47(17.8) 155.58(17.6) t(54) = -8.48 t(52) = -8.10 t(52) = 2.00 < .0001 *** < .0001 *** 0.051 ***significant at < 0,0001 level
Table 2. Measurement results MBCT and Waitlist
MBCT (n= 9) Waitlist (n = 37)
Pre Post Pre Post
M (SD) M (SD) M (SD) M (SD) Group x time effect
CAARS- Self report
P value
Inattention 24.7(3.8) 21.7(3.2) 16.6(4.5) 16.1(3.8) .104 Hyperactive-impulsive 23.6(2.9) 17.4(2.3) 13.6(4.5) 12.6(5.0) .000*** ADHD (total) 48.2(4.8) 39.1(4.6) 30.2(6.5) 28.8(6.9) .002**
OQ-42.5 Global score 112.0(12.0) 98.8(15.9) 69.1(17.5) 66.6(24.0) .102
BRIEF-ASR
Total 141.3(21.3) 137.1(13.3) 156.0(16.6) 153.8(18.8) .665
** significant at 0,01 level ***significant at < 0,0001 level
Table 3. Pre-post measurement results MBCT MBCT (n= 9 ) Pre Post M (SD) M (SD) P value FFMQ 76.2(4.9) 76.3(10.1) .976 SCS 45.9(10.3) 49.4(5.8) .219 SF-12 33.0(2.9) 31.9(1.5) .197
Figure 4. Change in self-compassion across time and standard errors (SE) of MBCT group (n = 9).5
5 Change is not significant at level p < .05.
Results: qualitative analysis
Evaluation form
10 participants in the treatment group completed the study (completion was operationalized as an attendance to at least 4 sessions). Participants attended to an average of 7 (SD = 2.8) out of 9 sessions (including the silence day), indicating an attendance rate of 77.8% of sessions.
In general, participants (N = 8) evaluated the mindfulness training evaluation questionnaire. 3 items assessed the satisfaction with the training material and 7 items assessed satisfaction regarding the sessions and different training components. On a scale ranging from 1 (not useful at all) to 5 (very useful), participants reported that both the training material and the overall sessions were considered useful (both: M = 4.0, SD = 0.5). Overall treatment received a grade of 8.4 (0.9), indicating an overall high satisfaction with the training (on a scale from 1 to 10). All participants indicated that the training duration was adequate and that they would continue practicing mindfulness in the future.
Regarding the preference for group composition, all participants indicated to have a preference for a group with only ADHD participants (opposed to an
heterogeneous group). 25% of the participants indicated a preference for training without a specific emphasis on ADHD symptoms, whereas 75% showed a preference for sessions specifically targeting ADHD symptoms.
With respect to peer contact, all participants liked to share experiences
concerning their ADHD symptoms (M = 5, SD = 0). They also felt supported by each other (M = 4.5, SD = 0.8).
Regarding the different training components, overall satisfaction rate was sufficient (indicated by a mean score above 3). The lying yoga practice and standing meditation were evaluated the least positively (both: M = 3.1 SD = 1.1), whereas the sitting meditation was the most well liked exercise (M = 4.4, SD = 0.7).
Focus interviews
Core categories were previously identified, referring to the Feasibility (F) and process of change (P) during and after mindfulness training. Participants’ answers were used to specify subcategories (see Table 1).
Table 1. Categories and subcategories
Categories Subcategories
F Facilitating factors Peer contact
Personal characteristics Course content/structure Supervision
F Limiting factors Course components
Personal characteristics
F Adaptations Course content
Instructions
Future maintenance P Mindfulness qualities Acceptance
De-identification Intention
Non judgment Act with awareness
P Changes Integration Recognition ADHD symptoms Emotion regulation Well-being Facilitating factors
This category concerned factors that encouraged participants to continue the mindfulness training and homework exercises.
Peer contact. Participants indicated to find peer contact helpful, specifically the
exchange of experiences and the recognition of behavioural patterns and symptoms due to ADHD. For example, a participant mentioned: “It is funny, we have a lot of
things in common, when she (the trainer) asked: what did you think about the sitting meditation? And she talked quite slowly, and then, somebody said: you talk slowly, and that bothered me, and everyone was sitting like: yes, yes yes.” Another
or about falling into the automatic pilot (…) helped me a lot.” A participant
indicated to feel “like another species of animal, who suddenly found his fellow
species”.
Personal characteristics. There were also personal characteristics mentioned,
contributing to treatment adherence, such as determination, curiosity and openness to experience. A participant indicated to find his hyperfocus (which is a common characteristic in ADHD) facilitating: “I can not sit down easily. But once you’re in,
I am really in. Maybe it is because of the hyperfocus at a certain moment”.
Course content and structure. With respect to course content and structure,
participants appreciated the variation in exercises, allowing for different physical movements and positions. One participant found it helpful to look differently at the exercises: “I don’t really see it as walking (…) I even don’t call it walking because
when I walk, I walk very fast, and then I don’t like to walk that slowly, but as part of an exercise I do”. Another participant indicated to find it helpful to attune
breathing and walking rhythm: “when inhaling lift your foot and when exhaling put
your foot down”. Noticing a positive effect due to the course was also considered
helpful. A participant told: “during the course you notice that it really brings you
something, and on a certain moment, you really make a changeover to wanting to do the them (the exercises)”. A participant emphasized the importance of choosing
the exercise that most suits you: “I saw that you should take the exercise you
consider the most helpful. That relaxes you.” The overall structure of the training
and practitioners’ involvement was also evaluated positively: “I have difficulty
with going somewhere. And when I don’t do an exercise, I run away from it, because otherwise the threshold is too high, and then she (the trainer) phoned me and asked: what will you do when you miss your training next week?”.
Supervision. Trainers were said to be directed towards the client, without judging
them on their ‘ADHD label’. Moreover, trainers emphasized self-care, which was evaluated positively: “When you want to get coffee, you could just get up and get
coffee (….). I did not do it, but it feels nice that they created that space, so to speak”. Another participant: “That (self-care) was crucial for the climate during
the course. I am here for myself, to get something I find important. And I am allowed to create an environment where I feel comfortable”.
Limiting factors
This category referred to problems encountered during the mindfulness training.
Course components. Participants considered the slowness of some exercises to be
an obstacle, sometimes provoking restlessness: “walking meditation, I get restless
(…), I tried it, but it is just too slow”. Or: “(during the walking meditation in the
group) I could not concentrate because I had the feeling that we were doing the
zombi-apocalyps”. During the silence day, one participant felt the strong need for
social interaction: “I am proud that I made it, but there was a moment that I was
doubting about whether to go home or to stay there”. This also seemed closely
related to experienced ADHD symptoms. Participants argued that presenting homework as an obligation had adverse effects. That is, when homework was presented as an obligation it was considered as a “big mountain you have to get
across, which makes me want to resign”. A participant indicated having practiced
more in the weeks after training, since homework was not compulsory then. Regarding psycho-education, a participant indicated that some psychological concepts were insufficiently elaborated: “Once a triangle was described on the
white board, about physical sensations, feelings, and thoughts, and I felt it was not clear”. It was also suggested that the final homework exercises could have been
explained more comprehensively because they required more discussion and elaboration.
Personal characteristics. Some underlying personal factors could explain the
difficulties experienced with homework: “You feel guilty when you haven’t done it
(homework).” Another reaction: “Sometimes you set the bar too high, and you do not reach your goal”. Therefore, high self-expectations of the participants may
explain some resistance to homework instructions. Some participants found it challenging to be confronted with personal flaws: “I practice gymnastics, so, I am
flexible, but these are different exercises where I am not good at, and that is
practice. Avoiding feelings of anxiety also constituted a barrier to continue with mindfulness practice for some participants: “I think it is the anxiety of being silent.
The fear of completely letting go. Just being completely calm. (…). It is a fear of sitting quietly because you do not know what to expect”.
Adaptations
This category referred to adaptations of the mindfulness course that might be helpful according to the participants.
Course content. Some participants indicated to prefer the short meditation
homework exercises instead of the longer ones. Some participants found it difficult to focus when there was a silence break on the audio program; therefore they suggested more reminders in the form of verbal instructions or a singing bowl.
Instructions. The majority of participants suggested more emphasis on the willingness instead of the obligation to practice mindfulness in order to increase
practice and commitment.
Future maintenance. Participants expressed a preference for mindfulness booster
sessions with the same ADHD peers, because of the grown confidentiality and openness between the participants.
Mindfulness qualities
Some mindfulness qualities developed by the participants were: de-identification, acting with more awareness, re-perceiving, acting more intentionally, and being less judgmental.
Acceptance. Participants argued being more acceptant toward their experiences,
and paying more attention to stress signals and physical movements. ADHD symptoms were recognized more easily.
There was de-identification: “You have thoughts, but you are not all those thoughts
Participants also recognized their own influence in situations, and were more conscious of behavioral patterns, and could consequently make intentional decisions. One participant explained; during the mindfulness training I always
wore a sweat pants and after the training I wanted to put my jeans back on. (…). But then, everyone was gone and I thought: I can never chat after the training, and I found that a pity. (…) But then I thought: For just once, I will not help storing the cushions, and I changed instead. (…). And then I walked with a participant to the station, and I really enjoyed it.
Non-judgment. Participants showed to have developed a less judgmental attitude: “Yes, at the beginning, I noticed…. You wander off in thoughts or you make over-hasty judgments, and that is what you really learn: you should not do that; you should notice it and come back to yourself. For me, that was the most important, that I could just stay neutral, and that I could say at some point: yes, I could recall myself, instead of saying: I wandered off.”
A participant indicated to act with more awareness: “They are still there
(thoughts), but I can now make a choice, I don’t need to do nothing with them. (…). I can deal with them later.” Another participant suggested: “I always found it difficult to say no. (…). I can now make clearer choices. I know when I have to choose for myself.”
Changes
This category concerned changes in daily life and well-being during or after the mindfulness training.
Integration. Participants noticed that they integrated the mindfulness skills in their
daily life: “Yes, you begin to internalise them (mindfulness skills). (…). You
already understand the idea, but your daily acts, it begins to incorporate in them too.”
Recognition. Participants recognized more ADHD symptoms: “You realize that ADD is very broad; it is not just a concentration problem, but it involves much more”. Due to this recognition of symptoms, some participants indicated an
and that I can adapt to it”. A participant suggested: “I feel I can stand up for myself, when I need something. And afterwards, I can continue with my work, whereas I was used to defend myself, instead of saying: I need this”.
ADHD symptoms. Regarding overall ADHD symptoms, some participants noticed
a decrease in hyperactivity because they allowed themselves to experience feelings of restlessness: “I really noticed I was into it (hyperactivity). (…). And now I can
take a step back and take it easy and try to relieve stress through paying attention to my breathing”. However, one participant indicated to experience an increase in
hyperactivity: “I have a better overview now, I see it happening now (…) and I can
allow more (feelings). So, I have become more hyperactive, or more outgoing, something I already was, but more numb”. Participants were more able to organize
their thoughts: “I can now decide what (thoughts) I don’t need and which ones I
can throw away (…) and I realize that I can recover stored thoughts when I have time for them”.
Emotion regulation. Some participants suggested to accept more negative
emotions: “I think I allow more anxious feelings, and now I am less afraid.” A participant indicated being more aware of her emotions: “My emotions always
went up and down, that is, I can get totally upset because of the smallest things, but the smallest things can also make me the happiest person on earth. But now, I let it go. I know that when I withdraw for a moment, I can stay calm and look clearer at it, instead of becoming my emotion”.
Well-being. Participants indicated appreciating more things and being more
positive towards themselves: “my self esteem has improved. (…). I have accepted
that it sometimes does not go the way I want it to go, and that I have other passions, that could fit in better.” Different participants experienced a breaking
point after the silence day: “Afterwards, I could let it go, it was easier to say no.
You are silent a whole day so you consciously do not do things, and you
consciously do not search social interaction. (…). That creates space. And from that moment on, I thought: what are we worrying about?”
Discussion study 2
Study 2 consisted of 2 sections: a qualitative analysis and a quantitative analysis. According to the qualitative analysis, MBCT seems a feasible and acceptable treatment for adult ADHD. Participants indicated having experienced an
improvement in ADHD symptoms and well-being, to act with more awareness, to make more intentional decisions, to be more acceptant towards themselves and to be less judgmental. Moreover, attendance rate was 77% and the overall training components were rated positively, not indicating any necessary modifications to improve treatment adherence.
According to the quantitative analyses, MBCT had a significant effect on hyperactivity and impulsivity symptoms relative to the waitlist group of study 1. No changes between pre- and post assessment were found on quality of life, self-compassion, mindfulness skills, and executive functioning. Nevertheless, all results should be interpreted with caution given that sample size was too small and statistical power could not be ensured. Importantly, quantitative results were not decisive in the decision to proceed with a RCT in the future.
Some limitations of the second study should be considered. First, the
qualitative analyses were conducted with participants who completed the training (attending to 4 or more sessions). Although one participant dropped out, the results may look too promising, since it is possible that only those participants having positive experiences with MBCT provided feedback. Second, qualitative research was conducted on only two groups, without having reached theoretical saturation in order to justify appropriate sample size. Theoretical saturation refers to the point where no new information or themes can be subtracted from qualitative data (Guest, Bunce, & Johnson, 2006). Therefore, the identified categories and themes may be too restricted, missing possible variation in answers or not revealing disconfirming information (Brunce, & Johnson, 2006). Therefore, the current research will continue performing focus interviews, however this is beyond the scope of the present article.
Third, concerning quantitative analyses, the control group of the second study pertained to the first study. As such, there was no random allocation process, which could have introduced bias. Moreover, time lag between pre- and post
assessment differed 12 and 9 weeks for the control and MBCT group respectively, not allowing for any control of additional time effects.
Lastly, participants in the MBCT group experienced considerably more baseline ADHD symptoms and impairments in quality of life, compared to
participants in the waitlist group. Therefore, results are difficult to interpret. Future research may control for such differences, or choose a subsample with similar baseline characteristics.
Despite the mentioned limitations, the second study provided important insights in the feasibility and acceptability of an original MBCT protocol, showing
preliminary evidence for the effectiveness of shorter stand-alone MBCT in the treatment of adult ADHD.
Conclusion
We found support for the effectiveness of adapted MBCT+ training for adult ADHD. The effects of the MBCT+ may not only be attributed to the additional component of extensive psychoeducation, since stand-alone MBCT also showed promising results. A larger randomized controlled trial with an original MBCT protocol is warranted.
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