Underlying mechanisms and efficacy of a suicide-focused psychological intervention for psychosis: The Cognitive AppRoaches to coMbatting Suicidality (CARMS), multicentre, single-masked, randomised controlled trial conducted in the UK:The CARMS RCT

Background <br/>There is a need for theoretically-grounded, testable, suicide-focused psychological therapies, especially in people with severe mental health problems, specifically non-affective psychosis. We aimed to test both the underlying mechanisms and efficacy of a suicide-focused therapy, namely, Cognitive Behavioural Suicide Prevention for psychosis (CBSPp).<br/>Methods<br/>We conducted a four-site, randomised controlled trial with two conditions of treatment (CBSPp therapy plus Treatment-As-Usual [TAU]) and control (TAU alone), and three time-points of baseline, 6- and 12-months, with 6-months being critical. Experts-By-Experience were involved in all stages of the research. Randomisation was stratified by NHS site and anti-depressant medication. Assessors, the trial statistician, and one co-principal investigator, were masked to allocation condition. Main inclusion criteria were being 18 years of age or over; a diagnosis of non-affective psychosis; self-reported suicidal experiences in the three months prior to