ADHD is associated with pervasive cognitive, emotional and functional impairments and increased rates of coexisting disorders. Epidemiological studies indicate 25-45% of prison inmates to have ADHD. However, ADHD is often unrecognised in prison inmates and stimulant treatment was not previously evaluated in this group.

Provide effective treatment for prison inmates established with ADHD.

Evaluate efficacy and long-term effectiveness of osmotic-release oral system methylphenidate (OROS-MPH) in adult male long-term prison inmates with ADHD.

A 5-week randomised, double-blind, placebo-controlled, fixed-dose (72 mg/d) trial was conducted in 30 prison inmates with ADHD and coexisting disorders. In a following 47-week open-label extension (OLE), flexible-dosing OROS-MPH was provided alongside psychosocial interventions within a high-security Swedish prison. Primary outcome was change in ADHD symptoms after 5 weeks (CAARS: O-SV). Secondary outcomes included self-reported ADHD symptoms, global severity, global functioning, cognition, motor activity, institutional behaviour and quality of life.

OROS-MPH was highly effective and overall safe, both in the short-term relative to placebo (Cohen’s d=2.17; NNT=1.1), and in the long-term when provided alongside psychosocial interventions. Treatment continued to improve ADHD symptoms, global functioning, motor activity, cognition, quality of life, and behaviour control over the 47-week OLE. No drug misuse was reported and a majority of participants completed rehabilitation programs.

OROS-MPH effectively improved symptoms and functional impairments of ADHD in prison inmates with ADHD. We suggest that OROS-MPH provided alongside rehabilitation programs could be a feasible and effective multimodal intervention for adults with ADHD and coexisting disorders within a prison setting