CAPOPUS Trial: an Observer-blinded RCT of Specialized Addiction Treatment Versus Standard Treatment for Young Patients with Cannabis Abuse and Psychosis

Abstract

Background:

A number of studies indicate a link between cannabis-use and psychosis as well as more severe psychosis in those with existing psychotic disorders. There is currently insufficient evidence to decide the optimal way to treat cannabis abuse among patients with psychosis.

Objectives:

The major objective for the CapOpus trial is to evaluate the effects of a specialized addiction treatment program adding group treatment and motivational interviewing to treatment as usual compared with just treatment as usual.

Design:

The trial is designed as a randomized, parallel-group, observer-blinded clinical trial. Patients are recruited through teams for early detection of people with psychosis, community mental health centers, and assertive community treatment teams. Patients are randomized to one of two treatment arms, both lasting six months:

1. 1. specialized addiction treatment plus treatment as usual or

2. 2. treatment as usual.

The specialized addiction treatment is manualized and consists of both individual and group-based motivational interviewing and cognitive behavioral therapy, and incorporates both the family and the case-manager of the patient.

The primary outcome measurement will be amount of reduction in cannabis consumption. other outcome measures will be improvements in psychosis symptoms, cognitive functioning, quality of life and social functioning, and cost-benefit of the treatments.