Cross-national differences in methylphenidate utilization in primarily adult psychiatric inpatients

OBJECTIVES: Methylphenidate (MPH) is a stimulant primarily used to treat attention-deficit/hyperactivity disorder (ADHD). This study examined cross-national differences in MPH utilisation among primarily adult psychiatric inpatients in Germany, Austria, and Switzerland. METHODS: Data were collected between 2007 and 2017 from psychiatric hospitals in Germany, Austria, and Switzerland participating in the AMSP pharmacovigilance program. RESULTS: Among 102,740 inpatients, 560 (0.55%) received MPH. The sample was young with a mean age of 33.9 years. The proportion of inpatients treated with MPH was highest in Switzerland (2%) and markedly lower in Germany and Austria (both 0.3%). Among MPH-treated patients, depressive disorders, neurotic and personality disorders and substance-related disorders were most prevalent. Overall, only 287 patients (51.3%) had an ADHD diagnosis. Men represented 58.6% of the MPH group and received higher daily doses than women. 87.1% of MPH-treated patients received at least one additional psychotropic drug. CONCLUSIONS: Adult MPH use in adult psychiatric inpatient care was rare, showed marked cross-national variation and was typically embedded in complex psychopharmacological regimens. The finding that only about half of MPH-treated inpatients had a documented ADHD diagnosis underscores the need for more detailed studies on indications, clinical decision-making and outcomes of MPH treatment in routine psychiatric practice.