Evidence Hub

A randomised controlled trial to evaluate the clinical and cost-effectiveness of Stimulant compared with Non-stimulant medication for adults with Attention-deficit/hyperactivity disorder and a history of Psychosis or biPolar disordER: SNAPPER

Loi S, Joshee P, Ottridge R, Woolley R, Gkini E, Asherson P, Young AH, Al-Janabi H et al.

Trials, 2025

244 participants

Abstract

Background: Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder involving inattention, hyperactivity and impulsivity, which starts in childhood and frequently persists into adulthood. Stimulant and non-stimulant medication are the mainstay of treatment in adults. ADHD in adults is commonly comorbid in people with severe mental illness (SMI) such as bipolar disorder (bipolar) and psychosis. There is substantial uncertainty over the effectiveness of stimulant and non-stimulant medication in adult ADHD comorbid with SMI. There is also concern that they could trigger or worsen psychotic or manic symptoms. Whilst National Institute of Health and Care Evidence (NICE) ADHD guidelines indicate available evidence does not justify a deviation from their main recommendations of using stimulants first line, this is based on limited studies within this comorbid population. A randomised controlled trial (RCT) is needed to address this evidence gap. We present a protocol for a pragmatic, observer-blind, multi-centre, two-arm, RCT called SNAPPER that aims to investigate the clinical and cost-effectiveness of stimulant compared with non-stimulant medication for adults with ADHD and a history of SMI.

Methods: The recruitment target is 244 participants, aged 18 years or above, who have a history of SMI (either bipolar disorder or psychosis) with ADHD. Having provided informed consent for screening, participants will undergo validated diagnostic screening…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 244 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free