B +any antipsychotic 2013.

Methods	Allocation: randomised. Blinding: single‐blind. Duration: 24 weeks*. Setting: outpatient. Design: parallel. Country: Japan.
Participants	Diagnosis: schizophrenia (DSM‐IV‐TR). N = 39. Sex: M 19 F 16 (data from participants who ended the study). Age: ˜ 36 years. History: chronic patients without acute exacerbation on a stable dose of 2 antipsychotics without prescription changes in the past 3 months.
Interventions	Combination therapy: continuing antipsychotics combination** Monotherapy: switch to monotherapy, each participant and physician decided together which of the two antipsychotics to discontinue. Discontinuation had to occur within 12 weeks
Outcomes	‐ Usable data ‐ Mental state: PANSS (Total, Positive, Negative). Adverse events: requiring discontinuation. ‐ Not usable data ‐ Leaving the study early (dates of discontinuation where not presented). ‐ Not used in this review ‐ Brief Assessment of Cognition in Schizophrenia and the Life Assessment Scale for the Mentally Ill.
Notes	* From 0‐12 weeks to discontinue polypharmacy, from 13‐24 weeks to evaluate monotherapy versus combinations. ** The most common baseline polypharmacy combinations were risperidone and a first‐generation antipsychotic (N =10), olanzapine and a first‐generation antipsychotic (N = 9), olanzapine and risperidone (N = 5), risperidone and quetiapine (N = 3), olanzapine and aripiprazole (N = 3), aripiprazole and a first‐generation antipsychotic (N = 3), quetiapine and aripiprazole (N = 2), blonanserin and a first‐generation antipsychotic (N = 2), blonanserin and olanzapine (N = 1), blonanserin and quetiapine (N = 1). No protocol‐ a priori was published.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	The patients were randomly divided into either the switching group or the continuing group using StatView.
Allocation concealment (selection bias)	Unclear risk	No information provided.
Blinding (performance bias and detection bias) All outcomes	High risk	“For participants who were assigned to switch to monotherapy, each participant and physician decided together which of the two anti‐ psychotics to discontinue.” “The raters were blinded about which group the patients belonged to.”
Incomplete outcome data (attrition bias) All outcomes	High risk	Reasons for missing data differ in both group and this was not addressed in the data analysis.
Selective reporting (reporting bias)	Low risk	All measured outcomes were reported.
Other bias	Unclear risk	Supported by Grant in Ministry of Education, Culture, Sports, Science and Technology Japan.