Lack of beneficial effect of planned treatment interruption in adults with ADHD treated with methylphenidate - clinical evidence.

OBJECTIVE: Planned weekend drug holidays during methylphenidate (MPH) treatment are used in clinical practice despite limited evidence in adults. This study compared continuous daily MPH use with planned weekend breaks in adult men with ADHD, focusing on real-world behavioral functioning, adherence, cognition, sleep, appetite, and adverse effects. METHODS: In this prospective observational comparative cohort study, adult men with ADHD receiving stable MPH treatment were not randomized by the investigators but were classified according to their pre-existing naturalistic treatment pattern established before study enrolment: continuous daily use (MPHC) or planned weekend breaks (MPH-PWB). Participants completed baseline and end-of-study questionnaires and cognitive tests and were followed for 28 days using structured daily diaries. RESULTS: Forty-three participants were included in the final analysis (MPHC, n = 23; MPH-PWB, n = 20). The weekend-break group showed higher mean daily procrastination (8.4 ± 1.4 vs. 7.5 ± 1.2; p = 0.028) and lower task completion (64.8% ± 12.6 vs. 74.1% ± 11.3; p = 0.017). Weekday-only analyses attenuated these differences. No clear between-group differences were observed in questionnaire outcomes, cognitive performance, sleep, appetite, adherence, or most non-cardiovascular adverse effects. Tachycardia occurred with similar frequency in both groups, whereas blood pressure elevation and palpitations were more frequent in the weekend-break group. CONCLUSIONS: In adult men receiving stable MPH treatment, planned weekend breaks were not associated with a clear overall advantage and were linked to less favorable diary-based behavioral functioning and more frequent selected self-reported cardiovascular adverse effects. Routine weekend discontinuation should not be assumed to improve treatment quality.