A nationwide analysis of 148,581 Swedish patients with a new disorder attention-deficit/hyperactivity disorder diagnosis found that those who began medication within 3 months had lower rates of suicidal behaviors, substance misuse, transport accidents, and criminality over a two-year follow-up. No statistically significant difference was observed for the first occurrence of accidental injuries, but all five measured outcomes showed reductions when recurrent events were considered.

Within 3 months of diagnosis, 57% of patients initiated attention-deficit/hyperactivity disorder (ADHD) treatment—primarily with methylphenidate (88%), followed by atomoxetine (8%) and lisdexamfetamine (3%). For those starting medication, rates per 1,000 person-years were lower than in untreated patients: suicidal behaviors (15 vs. 17), substance misuse (59 vs. 69), transport accidents (24 vs. 28), and criminality (65 vs. 76). Rates of first accidental injuries were 89 vs. 90, showing little difference.

When recurrent events were analyzed, reductions were observed across all outcomes, with the largest effects in substance misuse and criminality. Greater reductions were seen in patients with prior history of an event, in adults compared with pediatric and adolescent patients, and in female patients for first criminality events. Stimulant medications were linked to greater risk reductions than nonstimulants.

The study used a target trial emulation approach based on health care visits, death records, and criminal convictions, and accounted for demographic, clinical, and treatment variables to reduce confounding. Limitations included no data on non-drug treatments, adherence, dosing, ADHD subtype, and events not recorded in medical or legal systems. Findings may not generalize to settings outside Sweden.

Full disclosures are available in the published study.

Source: The BMJ