Abstract
BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) frequently persists into adulthood and is associated with impairments in attention, emotional regulation, executive functioning, and quality of life. Although mindfulness-based interventions (MBIs) have been proposed as promising non-pharmacological treatments, the evidence regarding their efficacy in adults with ADHD remains inconsistent. METHODS: A systematic search was conducted using the MEDLine, CINAHL, and PsycINFO databases to identify controlled trials published up to 2023. Studies were included if they evaluated the effects of MBIs in adults with ADHD using a control group, regardless of randomization. Only studies in which mindfulness was the primary therapeutic modality were included, even if limited psychoeducational or behavioral components were present. Ten studies met the inclusion criteria. Outcomes were categorized into 6 domains: self-reported and observer-rated ADHD symptoms, negative and positive affect, mindfulness skills, and functional outcomes. Meta-analyses were performed using standardized mean differences (SMDs) or mean differences with 95% confidence intervals (CIs). Risk of bias and publication bias were assessed using Cochrane tools and funnel plots, respectively. RESULTS: Statistically significant improvements were observed in self-reported ADHD symptoms (SMD = 0.48, 95% CI [0.19, 0.76]), observer-rated ADHD symptoms (SMD = 0.32, 95% CI [0.09, 0.56]), and functional outcomes (SMD = 0.56, 95% CI [0.22, 0.90]). However, there were no significant effects on mindfulness skills (SMD = -0.20, 95% CI [-0.47, 0.08]), negative affect (SMD = 0.31, 95% CI [-0.06, 0.67]), or positive affect (SMD = -0.21, 95% CI [-0.58, 0.16]). CONCLUSION: MBIs may be effective in improving core ADHD symptoms and overall functioning in adults with ADHD. However, their effects on emotional well-being and mindfulness skills remain inconclusive. These findings support the utility of MBIs as complementary interventions for ADHD while highlighting the need for further high-quality studies to clarify their long-term effects and mechanisms of action.