First-Dose Methylphenidate-Induced Changes in the Anti-Saccade Task Performance and Outcome in Adults with Attention-Deficit/Hyperactivity Disorder.

Objective: We examined whether the anti-saccade task (AST) performance after the first methylphenidate (MPH) dose could be associated with subsequent clinical outcome in adults with attention-deficit/hyperactivity disorder (ADHD).

Methods: Ninety-seven drug-naive DSM-5 ADHD adults participated in this study. The AST parameters were measured at baseline, after the first MPH-dose (10 mg orally), and 6 months after chronic MPH treatment. Results were compared with those of 50 healthy control (HC) subjects.

Results: At baseline, ADHDs showed longer saccadic reaction times and more direction errors than HCs (both  < 0.00001). Acute and chronic MPH administration resulted in normalization of the AST performances. Multivariate regression analysis after adjusting for age, sex, weight, and severity of symptoms at baseline, revealed that a low percentage of direction errors after the first MPH-dose (i.e., ≤10%) could predict remission at month 6 (OR: 5.84; 95% CI: 2.00-17.11;  = 0.001).

Conclusions: Our findings indicate that: (1) impairments of motor planning and response inhibition in adults with ADHD are improved with MPH, and (2) a low direction error percentage after the first MPH-dose may be an independent predictor of remission.ClinicalTrials.gov identifier: NCT03411434.