Edwards 2011.

Methods	Allocation: randomised Blinding: single‐blind Location: the Early Psychosis Prevention and Intervention Centre, Australia Length of follow‐up: 24 weeks
Participants	Diagnosis: first treated episode of a psychotic disorder (schizophrenia (n = 39); schizophreniform (n = 8); delusional disorder (n = 1)) N = 48 Sex: 34 M, 14 F Age: mean ˜ 21.4 years, SD ˜ 3.5 years Included: length of illness: not reported; registered with EPPIC for 12 to 26 weeks; and continuing to experience moderate to severe positive symptoms, defined as a score ≥ 4 on at least one of the hallucinations, unusual thought content, and conceptual disorganisation items of the expanded version of the brief psychiatric rating scale (BPRS), with a score of not less than 3 on these items for a period of 14 consecutive days or more during the preceding 12 weeks; treated with at least one atypical antipsychotic (usually risperidone, olanzapine or quetiapine) at doses up to 500 mg chlorpromazine equivalence (if tolerated), with demonstrated medication compliance for at least the past 4 weeks Excluded: an organic mental disorder, pregnancy or lactation, requiring antidepressant medication, a mood stabiliser or ECT, and a history of drug‐induced granulocytopenia
Interventions	1. CBT plus clozapine group*: N = 11 Content: a manualised CBT program, the systematic treatment of persistent psychosis (STOPP, Hermann‐Doig 2003) Delivered by: not reported Frequency: twice weekly Treatment duration: 12 weeks 2. CBT plus thioridazine group*: N = 12 Content: a manualised CBT program, the systematic treatment of persistent psychosis Delivered by: not reported Frequency: twice weekly Treatment duration: 12 weeks 3. Clozapine group*: N = 14 Content: Participants commenced treatment at a dose of 12.5 mg/day which was titrated upwards in 25 mg/day increments up to a maximum dose of 300 mg/day, depending on clinical response. Delivered by: not reported Treatment duration: 12 weeks 4. Thioridazine group*: N = 11 Content: Participants commenced treatment at a dose of 12.5 mg/day which was titrated upwards in 25 mg/day increments up to a maximum dose of 300 mg/day, depending on clinical response. Delivered by: not reported Frequency: every day Treatment duration: 12 weeks
Outcomes	Global state: clinically important change (no improvement)**, general (CGI scores) Mental state: positive symptoms (BPRS scores), negative symptoms (SANS scores), depression (BDI scores) Functioning: social (SOFAS scores) Quality of life: general (QLS scores)
Notes	*All participants received routine clinical care, which included access to a 24‐hour mobile assessment and treatment team, inpatient service, case management and psychiatric care. **Defined as a score of more than 3 on each item of the BPRS positive subscale (unusual thought content, hallucinations, and conceptual disorganisation) and a CGI severity rating of moderate or higher. We combined data from the two CBT groups as the single intervention group (CBT plus standard care); and combined data from the 'clozapine' and 'thioridazine' groups as the single control group (standard care).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "This study was conducted as a single‐blind randomised controlled trial..." (p.2). Comments: No details of the randomisation procedure were provided. Insufficient information to permit judgement of 'Low risk' or 'High risk'
Allocation concealment (selection bias)	Unclear risk	Comments: The author did not describe allocation concealment. Insufficient information to permit judgement of 'Low risk' or 'High risk'
Blinding of participants and personnel (performance bias) All outcomes	High risk	Comments: The author did not describe the blinding of participants and personnel. 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	Unclear risk	Quote: "...a single‐blind..." (p.2). Comments: no details of the object of blinding. Insufficient information to permit judgement of 'Low risk' or 'High risk'
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comments: The author did not state the number of participants leaving the study early, however, data were analysed according to the intention‐to‐treat (ITT) principle. Missing data were handled by using multiple imputation.
Selective reporting (reporting bias)	Low risk	Comments: All measured outcomes were reported.
Other bias	Low risk	Comments: The research was supported by the Victorian Government's Health Promotion Foundation and NOVARTIS. The funder did not play role in data collection, analysis, or interpretation.