Objective To examine the effects of drug treatment for attention deficit/hyperactivity disorder (ADHD) on suicidal behaviours, substance misuse, accidental injuries, transport accidents, and criminality. Design Emulation of target trials. Setting Linkage of national registers in Sweden, 2007-20. Participants People aged 6-64 years with a new diagnosis of ADHD, who either started or did not start drug treatment for ADHD within three months of diagnosis. Main outcome measures First and recurren...
