C +arip/pali 2014.

Methods	Allocation: randomised. Blinding: double‐blind. Duration: 6 weeks. Setting: outpatient. Design: parallel. Country: India.
Participants	Diagnosis: Schizophrenia (DSM‐IV). N = 90. Sex: * Age: ˜ 36 years. History: Receiving olanzapine for at least 6 weeks and showing partial or no response to PANSS Scale..
Interventions	Combination therapy: olanzapine (10 mg) + aripiprazole (10 mg) (N = 30). Combination therapy: olanzapine (10 mg) + paliperidone (3 mg) (N = 30). Monotherapy: olanzapine (3 mg to 6 mg) + placebo (N = 30).
Outcomes	‐ Usable data ‐ Leaving the study early. Mental State: PANSS total. ‐ Not used in this review ‐ Digit symbol substitution test, six digit cancellation test, critical flicker fusion test, arithmetic ability, verbal fluency test, digit span test, hand steadiness test, finger tapping test.
Notes	No clinical registration.. Funding: no funding sources. Conflict of interest: none declared. * The gender of the participants in the monotherapy group does not correspond to the number of participants included in the trial. No response when we tried contacting the author to clarify this issue.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	“The randomized treatment allocation sequence was generated by statistician using random number table.”
Allocation concealment (selection bias)	Low risk	“The code of this random allocation sequence was retained in the sealed envelope by this person and was opened only after the completion of study during analysis of data.”
Blinding (performance bias and detection bias) All outcomes	Low risk	“Double blinding was done by inserting aripiprazole or paliperidone or placebo tablet in a non‐transparent capsule.” “It was handed over along with identical plastic containers filled with the study drugs (45 capsules each of aripiprazole or paliperidone or placebo) to a third person not directly involved in this study.” “The patient as well as the investigator was unaware of the treatment being administered.”
Incomplete outcome data (attrition bias) All outcomes	Low risk	“All the randomized patients in each group have satisfactorily completed the study.”
Selective reporting (reporting bias)	Low risk	All outcomes reported in methods are presented in the results.
Other bias	High risk	Baseline imbalance in PANSS (total) values.