Zhang 2012.

Methods	Allocation: parallel, randomised Blind: not stated Setting: hospital (inpatient) Country: China Length of study: 8 weeks
Participants	Diagnosis: treatment‐resistant schizophrenia (CCMD‐3) Total N at randomisation = 84 Sex: male 37, female 47 Age (years): mean 38.4, SD not stated Length of illness (years): mean 18.6, SD not stated History: PANSS > 60; failure after 3 types of antipsychotics (at least 2 types of antipsychotics with different chemical structure) over the last 5 years. Exclusion criteria: patients with severe physical, organic brain disease; alcohol or drug abusers; patients with mental retardation or chronic decline schizophrenia; MECT contraindications.
Interventions	ECT group (n = 42): MECT + olanzapine Content: the initial dose of olanzapine was 5 mg/d, increased to therapeutic dose (no more than 20 mg/d). The mean dose of olanzapine was 15.3 mg/d. On the day MECT was administered, olanzapine therapy was stopped at noon. The ECT device was Thymatron. Frequency: for ECT, 3 times a week for the first 4 weeks, then once a week for another 4 weeks; for olanzapine, twice daily Course of treatment (MECT): 16 sessions Treatment duration: 8 weeks Control group (n = 42): Olanzapine alone Content: the initial dose of olanzapine was 10 mg/d, increased to therapeutic dose (no more than 25 mg/d). The mean dose of olanzapine was 18.5 mg/d. Frequency: twice daily Treatment duration: 8 weeks
Outcomes	Response to treatment: clinically significant response to treatment* Mental state: assessed by PANSS Adverse events: assessed by TESS
Notes	*Clinically significant response according to the Chinese evaluation criteria for clinical efficacy of mental illness (Weng 1991, "Concise psychiatry"): 1) cure: reducing rate ≥ 75%; 2) significant improvement: reducing rate between 50% and 74%; 3) improvement: reducing rate between 25% and 49%; 4) no clinical response: reducing rate < 25%. The clinically significant response to treatment was defined as cure + significant improvement. Contact information: Brain III Department of People's Liberation Army 261 Hospital, Beijing, China
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "...were divided randomly into two groups..." (p.141) Comments: The author described a random component in the sequence generation process, but no details were provided on randomisation method.
Allocation concealment (selection bias)	Unclear risk	Comments: The author did not describe the 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 participants and personnel could not be blinded as 1 group did not use ECT, and no sham‐ECT was used.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comments: The author did not describe the blinding of outcome assessment. Insufficient information to permit judgement of 'low risk' or 'high risk'.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comments: No missing outcome data.
Selective reporting (reporting bias)	Low risk	Comments: The protocol is not available; all outcomes stated in methods reported in results.
Other bias	Low risk	None obvious.

BPRS: Brief Psychiatric Rating Scale (lower is better); CCMD: Chinese Classification of Mental Disorders; CGI‐I: Clinical Global Impression ‐ Improvement scale (lower is better); CGI‐S: Clinical Global Impression ‐ Severity scale (lower is better); DSM: Diagnostic and Statistical Manual of Mental Disorders; ECT: electroconvulsive therapy; GAF: Global Assessment of Functioning (higher is better); HAM‐D: Hamilton Depression Rating Scale (lower is better); ICD‐10: International Statistical Classification of Diseases and Related Health Problems 10th Revision; ITT: intention‐to‐treat; MECT: modified electroconvulsive therapy; MMSE: Mini‐Mental State Examination (higher is better); PANSS: Positive and Negative Syndrome Scale (lower is better); SANS: Scale for Assessment of Negative Symptoms (lower is better); SAPS: Scale for Assessment of Positive Symptoms (lower is better); SD: standard deviation; TESS: Treatment Emergent Symptom Scale (lower is better); WCST: Wisconsin Card Sorting Testing (lower is better); WMS: Wechsler Memory Scale (higher is better); WMS‐MQ: Wechsler Memory Scale ‐ Memory quotient (higher is better)