A meta-analysis of randomized-controlled trials (RCTs) suggested that APP may be superior to APM in schizophrenia in terms of reduced treatment discontinuation and increased efficacy, particularly in patients with acute psychosis who were prescribed APP in an early phase combining two different antipsychotic classes [i.e. a first-generation (FGA) drug with clozapine or another second-generation antipsychotic (SGA)] for at least 10 weeks (Correll et al., 2009). Here, APP is linked to schizophrenia.