Impact of a physical exercise intervention on psychological resilience and mental ill-being in medical-naïve children with attention-deficit/hyperactivity disorder: a pilot randomised controlled trial

The study aimed to evaluate whether a 12-week physical exercise intervention would improve psychological resilience and mental ill-being (e.g. internalising and externalising symptoms) in medical-naïve children with Attention-Deficit/Hyperactivity Disorder (ADHD). In a parallel two-group randomised controlled trial (RCT) design, 30 children between 8-12 years (M_age = 8.62 ± 1.37) formally diagnosed with ADHD were assigned to a 12-week physical exercise intervention group (three sessions per week for 60 mins, moderate-to-vigorous physical activity [MVPA] intensity) or a control group (treatment as usual). Psychological resilience was measured by a self-reported Chinese version of the 25-item Connor-Davidson Resilience Scale, and mental ill-being was assessed by a parent-reported Chinese version of the 113-item Achenbach's Child Behavior Checklist. The 12-week physical exercise intervention with MVPA level revealed a significant improvement in psychological resilience (<i>F</i> = 4.82, <i>p</i> = .038) and a significant reduction in internalising symptoms (e.g. anxiety/depressed, withdrawn/depressed, and somatic complaints) (<i>F</i> = 7.11, <i>p</i> = .013) and externalising symptoms (e.g. rule-breaking behaviour and aggressive behaviour) (<i>F</i> = 21.09, <i>p</i> < .001) in the intervention group but not in the control group. Moderate correlations were revealed between the changes in psychological resilience and the changes in internalizing (<i>r</i> = -.557, <i>p</i> = .031) and externalising symptoms (<i>r</i> = -.647, <i>p</i> = .009) in the intervention groups (<i>n</i> = 15). The findings of this study provide initial support for the efficacy of physical exercise intervention on psychological resilience and mental ill-being and for the potential mechanisms of psychological resilience under the effects of exercise-induced mental ill-being improvements in children with ADHD.