This was a small trial in adults with ADHD (103 people aged 18 to 65) at a Dutch outpatient clinic. Half took part in a 12-week adapted mindfulness-based cognitive therapy program, and half were placed on a waiting list.
Compared with the waiting list, people in the mindfulness group had a larger drop in ADHD symptoms, both as rated by investigators and as reported by the people themselves. The size of this effect ranged from small to large. Their executive functioning, the everyday skills for planning and self-control, also improved more, as did their mindfulness skills. More people in the mindfulness group responded to treatment, meaning their investigator-rated symptoms fell by more than 30% (16 people, or 43.2%, versus 1 person on the waiting list).
The program did not do better than the waiting list for depression, anxiety, or overall daily functioning. Many people dropped out of both groups, and there was no follow-up, so it is not known how long any benefit lasted. The authors describe the evidence as preliminary and suggest adapted MBCT might be an addition to or an alternative to medication for adults with ADHD, and they call for larger trials with longer follow-up.
The numbers Stats and what the terms mean
The statistics behind the plain-language claims above.
- Hepark, 2015: ADHD symptoms versus the waiting list, Cohen's d 0.39 to 0.78; executive functioning, d 0.43 to 0.93.
What the terms mean:
- d is an effect size. Roughly, 0.2 is small, 0.5 is moderate and 0.8 is large. A minus sign shows the direction of the change, not its size.
Source: Sevket Hepark, Lotte Janssen, Alicia de Vries, et al.. The Efficacy of Adapted MBCT on Core Symptoms and Executive Functioning in Adults With ADHD: A Preliminary Randomized Controlled Trial. Journal of Attention Disorders (2015). doi:10.1177/1087054715613587