Barrowclough 2010.

Methods	Allocation: randomised Blinding: assessor blind Location: London and Manchester, UK Length of follow‐up: 24 months: trial (12 months) and follow‐up (24 months)
Participants	Diagnosis: non‐affective psychotic disorder (DSM‐IV) (diagnoses were established on the basis of case note review) N = 327 Sex: male and female (numbers not reported) Age: ˜ 39.5 years of age Length of illness: ˜12 years Included: in contact with catchment area‐based adult mental health services in the target localities; alcohol use exceeding 28 units for males, 21 units for females on at least half the weeks in the previous 3 months and/or use of illicit drugs on at least two days per week in at least half the weeks in the 3 months prior to assessment; DSM‐IV diagnosis of drug and/or alcohol dependence or abuse; no significant history of organic factors implicated in the aetiology of psychotic symptoms; English speaking; informed patient consent; and having a fixed abode. Having a fixed abode is operationalised as having a current address (including B & B or open access hostel) and evidence (e.g. from care coordinator) indicating that the person is more likely than not to have a reliable address throughout the 2 years. Excluded: not reported
Interventions	1: CBT group*: N = 164 Content: Psychological therapy consisted of 26 individual sessions delivered over 12 months. Treatment was built around two phases. The first phase used motivational interviewing to reinforce motivation to change. In phase two of the intervention, cognitive behavioural technique from both the psychosis and substance misuse evidence base was used to formulate a change plan to help the participants to implement and maintain changes (e.g. strategies for dealing with distressing voices and depressed mood, responding to relapses, and coping with cravings and urges). Delivered by: not reported Frequency: 26 individual sessions delivered over 12 months Treatment duration: 12 months 2. Standard care group: N = 163 Content: antipsychotic medication, outpatients and community follow‐up and access to community rehabilitation activities Delivered by: not reported Frequency: not reported Treatment duration: throughout trial
Outcomes	Global state: relapse Mental state: general, positive symptoms, negative symptoms, affective symptoms (PANSS scores) Adverse events: death Functioning: general (GAF scores) Satisfaction with treatment: leaving the study early Unable to use: Global state: mean relapse, mean hospitalisation (skewed data)
Notes	Barrowclough 2001 provided pilot data for this full trial. * Participants in CBT group also received the standard care intervention.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "...Randomisation was performed independently of the research team within each of the localities to the two groups (MiCBT plus standard care and standard care alone) after stratifying by variables which could be predictive of treatment participation or outcome: substance type (alcohol alone, drugs alone, alcohol and drugs) and main drug of use (cannabis, amphetamines; opiates; other). Other variables potentially predictive of participation or outcome, including chronicity of illness and gender, were recorded for use as covariates in the analyses of outcome. Allocation was done via a telephone link to a remote randomisation service using randomised permuted blocks with randomly varying block size". Comments: Reliable method of random sequence generation was used.
Allocation concealment (selection bias)	Low risk	Quote: "Allocation was done via a telephone link to a remote randomisation service using randomised permuted blocks with randomly varying block size." Comment: implied that allocation was concealed via the telephone randomisation service, even though the concealment was not explicitly described
Blinding of participants and personnel (performance bias) All outcomes	High risk	Comments: No details of the blinding of participants and personnel were provided. However, as the CBT was based on standard care, participants and personnel were not likely to be blinded.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Independent and blind assessment of the groups was carried out at a subsequent 4 assessment points over a 24 month follow‐up period....All potential unblinding of assessors was recorded and in cases where a researcher did become unblinded, a second assessor was allocated to continue with the follow up." Comment: Assessor was blinded.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: By the end of the study, at 24 months, 38% of the participants were lost to follow‐up; however, intention‐to‐treat analysis and robust treatment effect estimate was used.
Selective reporting (reporting bias)	Low risk	Comment: no selective reporting identified
Other bias	Low risk	Comment: no other bias identified