Locomotor activity measures in the diagnosis of attention deficit hyperactivity disorder: Meta-analyses and new findings

• We meta-analyzed locomotor activity in relation to ADHD diagnosis.
• We found comparable effects of greater activity in ADHD across methods.
• Effect sizes were medium-to-large for both children and adults with ADHD.
• In new data, we found overlapping effect sizes in children and adults with ADHD.
• The prominence of locomotor hyperactivity in adults with ADHD is underappreciated.

IntroductionOur aim was to assess differences in movement measures in attention-deficit/hyperactivity disorder (ADHD) vs. typically developing (TD) controls.MethodsWe performed meta-analyses of published studies on motion measures contrasting ADHD with controls. We also conducted a case–control study with children/adolescents (n = 61 TD, n = 62 ADHD) and adults (n = 30 TD, n = 19 ADHD) using the McLean motion activity test, semi-structured diagnostic interviews and the behavior rating inventory of executive function and Conners (parent, teacher; self) rating scales.ResultsMeta-analyses revealed medium-to-large effect sizes for actigraph (standardized mean difference [SMD]: 0.64, 95% confidence interval (CI): 0.43, 0.85) and motion tracking systems (SDM: 0.92, 95% CI: 0.65, 1.20) measures in differentiating individuals with ADHD from controls. Effects sizes were similar in studies of children/adolescents ([SMD]: 0.75, 95% CI: 0.50, 1.01) and of adults ([SMD]: 0.73, 95% CI: 0.46, 1.00). In our sample, ADHD groups differed significantly in number of head movements (p = 0.02 in children; p = 0.002 in adults), displacement (p = 0.009/p < 0.001), head area (p = 0.03/p < 0.001), spatial complexity (p = 0.06/p = 0.02) and temporal scaling (p = 0.05/p = 0.04). Mean effect sizes were non-significantly larger (d = 0.83, 95% CI: 0.20, 1.45) in adults vs. children/adolescents with ADHD (d = 0.45, 95% CI: 0.08, 0.82). In the concurrent go/no-go task, reaction time variability was significantly greater in ADHD (p < 0.05 in both age groups) than controls.ConclusionsLocomotor hyperactivity remains core to the construct of ADHD even in adults. Our results suggest that objective locomotion measures may be particularly useful in evaluating adults with possible ADHD.