Pagano et al.  measured the effects of a mindfulness-based group cognitive behavioral therapy (MCBT) for adolescents suffering from ADHD. MCBT includes lectures, homework assignments, a mindfulness exercises daily life (e.g., sitting meditation and mindful movements), and group discussions about homework. The intervention included 24 adolescents (12 and 12 in the experimental and control group respectively) and lasted for 12 weeks. Pre- and post-intervention, the adolescents completed self-reported questionnaires about mindfulness, and self-reported ADHD symptoms. After 12 weeks, adolescents in the experimental group showed a significant improvement of self-reported ADHD symptoms and mindfulness. The control group did not improve in any of the outcomes. The authors also found a significant correlation between mindfulness and ADHD symptoms in the experimental group only.
A study by Lutz et al.  investigated the efficacy of a mindfulness-based therapy for adolescents with ADHD. A total of 22 adolescents (13 and 9 in the experimental and control group respectively) received the Mindfulness-Based Adolescent Mind Fitness Training (MBA MFT) for 8 weeks. MBA MFT includes lectures, homework assignments, and daily life exercises, including a 5-week-long mindfulness meditation course. Adolescents and their parents were measured at post-test and 6-month follow-up. After 8 weeks, adolescents reported a significant improvement on inattention and hyperactivity, and improved their behavior at school. Adolescents and their parents reported a tendency towards improvement on the mindfulness constructs. However, there was no significant difference in the behavioral outcomes between adolescents and their parents. There was a significant correlation between pre- and post-treatment mindfulness scores for adolescents and their parents.