Adults with attention-deficit/hyperactivity disorder (ADHD) who received 8 weeks of either mindfulness intervention (MAP) or psychoeducation (PE) experienced a reduction in ADHD symptoms and improved working memory performance, according to a new study published in Behaviour Research and Therapy. Furthermore, the researchers identified brain regions triggered by MAP using functional MRI (fMRI).
“When applied as a clinical intervention, mindfulness is intended to increase one's awareness of internal and external experiences of the present moment,” wrote corresponding author Katharina Bachmann, University Clinic for Psychiatry and Psychotherapy, University of Oldenburg, Bad Zwischenahn, Germany, and colleagues. “It teaches patients to respond more adaptively to the physiological and psychological processes involved in psychiatric disorders.”
PE is an intervention that focuses on improving a patient’s insight into disease. Previous researchers have demonstrated that PE is effective in attenuating symptoms of ADHD.
For this study, Bachman and colleagues examined the effects of MAP and PE on working memory in adult participants with ADHD. The researchers explored the memory-associated neurobiological effects of MAP compared with PE in adult ADHD patients, thus closing the gap in the literature identified by the study. They hypothesized that there would be increased brain activation in the frontoparietal regions and basal ganglia in the MAP group. They also hypothesized that MAP would elicit greater brain activation and that working memory would improve more in the MAP group.
The researchers analyzed data from before and after interventions in 21 MAP and 19 PE subjects. They collected data on severity of ADHD symptoms using the self- and observer-rated Conners Adult ADHD Rating Scales, took fMRI measurements, and recorded results from a one-back letter test to assess working memory. They evaluated subjects 2 weeks prior to the start of treatment and then at the end of the study, or after 8 weekly 2.5-hour sessions of PE or MAP.
The investigators found that although there were significant improvements experienced in both the MAP and PE groups with respect to ADHD symptoms and working memory performance, there was no difference between the groups.
The authors provided three possible explanations for this finding—a finding that ran contrary to their initial hypothesis.
- It could be that both MAP and PE tap into working memory function as assessed by an n-back task, and improve performance on the task in different ways.
- The MAP intervention was too brief to elicit neurobiological effects.
- This study was under-powered with a sample size too small to detect treatment outcomes.
Nevertheless, on further examination of fMRI, the researchers found increased task-related activation in the right parietal lobe after both PE and MAP. In support of their initial hypothesis, they also found a mindfulness-associated boost in brain activation in areas linked to working memory such as the bilateral inferior parietal lobule, precuneus, and right posterior insula.
“This is the first study that could show that mindfulness meditation influences brain regions associated with impaired working memory functioning and inattention in adults with ADHD,” the researchers concluded. “The current findings suggest that MAP may be an effective neuropsychotherapeutic approach for regulating ADHD-related brain dysfunction in adults.”
The study was funded in part by the Federal Ministry of Education and Research (Germany).