Randomised controlled trial of the short-term effects of OROS-methylphenidate on ADHD symptoms and behavioural outcomes in young male prisoners with attention deficit hyperactivity disorder:CIAO-II study

(237/300 words)Background: 20-30% of prisoners meet diagnostic criteria for attention-deficit/hyperactivity disorder (ADHD). Methylphenidate reduces ADHD symptoms but effects in prisoners are uncertain due to 16 comorbid mental health and substance use disorders. Aim: To estimate the efficacy of an Osmotic-Release-Oral-System methylphenidate (OROS-methylphenidate) in reducing ADHD symptoms in young adult prisoners with ADHD. Methods: An 8-week parallel arm, double-blind, randomised, placebo-controlled trial of OROS-methylphenidate versus placebo in male prisoners (aged 16-25) meeting DSM-5 criteria for ADHD. Primary outcome was ADHD symptoms at 8-weeks using the investigator rated Connors Adult ADHD Rating Scale (CAARS-O). Thirteen secondary outcome measures included emotional dysregulation, mind-wandering, violent attitudes, mental health symptoms, and prison officer and educational staff ratings of behaviour and aggression.Findings: Mean CAARS-O at 8 weeks in the OROS-methylphenidate arm was estimated to be reduced 26 by 0.57 points relative to the Placebo arm (95% CI: -2.41 to 3.56) and non-significant. The responder rate, defined as a 20% reduction in CAARS-O scores was 48.3% for the OROS-methylphenidate arm28 and 47.9% for the placebo arm. No statistically significant trial arm difference were detected for any of the secondary outcomes. Mean final titrated dose was 53.8 mg in the OROS-methylphenidate arm.Conclusions: ADHD symptoms did not respond to OROS-methylphenidate in young adult prisoners. The findings do not support routine treatment with OROS-methylphenidate in this population. Further research is needed to evaluate effects of higher average dosing and adherence to treatment, multimodal treatments, and preventative interventions in the community.Trial registration: EudraCT Number 2015-004271-78; ISRCTN16827947. Database lock 27th August 2019