Neurocognitive effects of methylphenidate in adults with attention-deficit/hyperactivity disorder: A meta-analysis.

PIEVSKY, M. A., and R. E. McGrath. Neurocognitive effects of methylphenidate in adults with attention-deficit/hyperactivity disorder: A meta-analysis…NEUROSCI BIOBEHAV REV 81(1) XXX-XXX, 2017.- This meta-analysis summarized 21 double-blind randomized controlled trials with a mean study duration of 18 days comparing the neurocognitive functioning of adults with attention-deficit/hyperactivity disorder (ADHD) on methylphenidate vs placebo. Effect sizes were weighted using a random-effects model. Scores on neurocognitive measures and tests of driving ability were on average higher on methylphenidate than on placebo, g = 0.17, p < .01, 95% CI = [0.05, 0.28], with little heterogeneity, Q(20) = 15.05, p = .77, I = 0. Performance on methylphenidate was significantly better than on placebo for the following domains: working memory (mean g = 0.13, 95% CI = [0.00, 0.26]), reaction time variability (0.16, [0.03, 0.28]), vigilance (0.22, [0.11, 0.33]), driving (0.22, [0.10, 0.34]), and response inhibition (0.23, [0.10, 0.36]). Quantitative and qualitative assessment revealed evidence of publication bias. Summarizing across studies, methylphenidate improved the performance of adults with ADHD on neurocognitive measures and tests of driving, suggesting that methylphenidate is an effective treatment for adults with ADHD and can improve processes related to attention and concentration.