Variability of kinematic graphomotor fluency in adults with ADHD.

•Examined kinematic graphomotor fluency variability of adults with ADHD.•Fluency variability between groups was similar on a familiar graphomotor task.•Fluency variability of the ADHD group was significantly greater on the novel task.•Variability of performance extends into the graphomotor domain in adults with ADHD.•Adults with ADHD may automatize graphomotor programs differently.