Study	Reason for exclusion
Agid 2013	Allocation: not randomised
Bondolfi 1995	Allocation: randomised, no further details Participants: schizophrenia, treatment‐resistant (defined by unresponsiveness or intolerance to appropriate doses of 2 different classes of conventional antipsychotics for at least 4 weeks each); no run‐in phase to confirm that participants have not responded to their current antipsychotic treatment. Interventions: risperidone versus clozapine; no antipsychotic dose increase versus antipsychotic switching group comparison; drug dosages could be changed after day 14 depending on each participant's response.
Buckley 1995	Allocation: not indicated Participants: people with schizophrenia whose baseline clozapine concentrations fell below 370 ng/ml. Interventions: clozapine dose increase versus maintenance; no antipsychotic switching group.
Conley 2003	Allocation: randomised, no further details Participants: were eligible if they met criteria for treatment resistance; all receiving conventional antipsychotics, risperidone or olanzapine prior to study initiation. Interventions: olanzapine versus clozapine; no antipsychotic dose increase versus antipsychotic switching group comparison.
Dunn 2005	Allocation: double‐blind phase: randomised; open‐label phase: not randomised. Participants: were eligible if they had received haloperidol for 6 weeks and showed lack of response. Interventions: double‐blind phase: no antipsychotic dose increase group; open‐label phase: no comparison, only ziprasidone was administered.
Ganguli 2003	Allocation: randomised, no further details Participants: were eligible due to tolerability issues as well; not only non‐responders. Interventions: 3 switching paradigms; no dose increase group
Goff 2013	Allocation: randomised, no further details Participants: were eligible if they had firstly received open‐label ziprasidone treatment, titrated up to 160 mg/day, for a minimum of 3 weeks and had persistent psychotic symptoms defined by a score of 4 (moderate) or greater on any item of PANSS. Interventions: ziprasidone dose increase versus ziprasidone dose maintenance; no antipsychotic switching group.
Harvey 2007	Allocation: randomised, no further details Participants: were eligible due to tolerability issues as well; not only non‐responders. Interventions: clozapine versus ziprasidone; no dose increase group.
Hatta 2012	Allocation: randomised and concealed; "a random number table", "sequentially numbered, opaque, sealed envelopes" (p. 195). Participants: were eligible if they had firstly received flexible‐dose oral risperidone treatment for 2 weeks and were considered to be non‐responders according to the Clinical Global Impressions‐Improvement scale (a score of 4 or higher). Interventions: risperidone dose increase versus risperidone augmented with olanzapine; no antipsychotic switching group.
Honer 2010	Allocation: randomised and concealed; "with a computerized schedule", "the person who generated the randomization schedule was not involved in determining subject eligibility, administering treatment, or determining outcome" (p. 14). Participants: were eligible if they had firstly received open‐label quetiapine treatment of 800 mg/day for 4 weeks and had persistent positive and negative symptoms and a rating in the Clinical Global Impressions scale of at least 4. Interventions: quetiapine dose increase versus quetiapine dose maintenance; no antipsychotic switching group.
Janicak 1994	Allocation: randomised, no further details Participants: acutely psychotic (primarily people with schizophrenia) that were non‐responders to haloperidol treatment for 2 weeks. Interventions: low versus middle versus high haloperidol plasma level; no antipsychotic switching group.
Kane 1988	Allocation: randomised, no further details Participants: were eligible if they had firstly received single‐blind flexible haloperidol treatment (up to 60 mg/day or higher) for 6 weeks and were considered to be non‐responders. Interventions: clozapine versus chlorpromazine; no antipsychotic dose increase group.
Kane 2007	Allocation: randomised, no further details. Participants: were eligible if they had received at least 15 mg/day olanzapine or 6 mg/day risperidone for a minimum of 3 weeks and showed no significant improvement. Interventions: aripiprazole versus perphenazine; no antipsychotic dose increase group.
Kim 2013	Allocation: not randomised.
Kinon 2010	Allocation: randomised and concealed; "interactive voice response system", "the precise response criterion was withheld from research staff but defined a priori in the Institutional Review Board (IRB) Supplement, and early responder/non‐responder status was identified and treatment randomization was implemented using an interactive voice response (IVR) system" (p583). Participants: were eligible if they had received single‐blind (i.e. to dose and dose adjustments), flexible‐dose therapy with risperidone 2 mg/day to 6 mg/day for 2 weeks and did not respond to treatment. Interventions: risperidone versus olanzapine; no antipsychotic dose increase group.
Lindenmayer 2011	Allocation: randomised, no further details Participants: were eligible if they had firstly received open label quetiapine 600 mg/day for 4 weeks and did not demonstrate an initial response defined as ≤ 15% PANSS total score reduction. Interventions: quetiapine 600 mg/day versus 1200 mg/day; no antipsychotic switching group.
McEvoy 2013	Allocation: randomised, no further details. Participants: non‐acute patients appropriate for switching current antipsychotic medication; not indicated if they were non‐responders. Interventions: 3 switching strategies to lurasidone; no antipsychotic dose increase group.
NCT00161018	Allocation: randomised, no further details. Participants: optimised with routine antipsychotic treatment for 4 to 6 weeks to prospectively establish lack of response to conventional antipsychotic therapy. Interventions: lack of response to 4 to 6 weeks' conventional antipsychotic therapy, then randomisation to quetiapine, risperidone or fluphenazine; no antipsychotic dose increase group.
NCT00191555	Allocation: randomised, no further details. Participants: were eligible due to tolerability issues as well; not only non‐responders.
Potkin 1994	Allocation: randomised, no further details. Participants: were eligible if they were judged to be non‐responders to conventional antipsychotics. Interventions: randomised to clozapine 400 mg/day or 800 md/day; no antipsychotic switching group.
Sacchetti 2009	Allocation: randomised; "randomised on a centralized basis" (p. 82). Participants: were eligible due to lack of tolerance as well; not only non‐responders. Interventions: ziprasidone versus clozapine; no antipsychotic dose increase group.
Simpson 1999	Allocation: randomised, no further details. Participants: people with treatment refractory symptoms of schizophrenia. Interventions: clozapine 100, 300 or 600 mg/day; if no improvement was observed after 16 weeks, participants were randomised to one of the other two dosages, no switching group.
Suzuki 2007	Allocation: not randomised; randomisation to treatment algorithms, switching of all non‐responders.
Weiden 2003	Allocation: randomised, no further details Participants: stable outpatients with persistent symptoms or troublesome side effects; not non‐responders. Interventions: 3 switching strategies to ziprasidone; no antipsychotic dose increase group.
Wirshing 1999	Allocation: randomised; "a computerized random‐number‐generating program" (p. 1375). Participants: were eligible due to lack of tolerance as well; not only non‐responders. Interventions: risperidone versus haloperidol; no antipsychotic dose increase group.