Temmingh HS, et al. - Given that patients treated with antipsychotics and comorbid substance use disorders (SUDs) frequently exhibit extrapyramidal side-effects (EPSE), researchers here investigated if patients with psychotic disorders and co-occurring methamphetamine (MA; a dopaminergic neurotoxin) use disorders exhibit EPSE more often. Further, they investigated the association between MA use, antipsychotic type, dose and EPSE. Data from three separate primary studies were extracted for this secondary analysis. The sample comprised of 102 patients (65.7% were male) with non-affective or affective psychotic disorders; Of these, 54.9% had schizophrenia spectrum disorders, 20.5% bipolar type I disorder with psychotic features, 11.7% schizoaffective disorder, and 12.7% had substance-induced psychosis. EPSE was observed significantly more frequently among patients with a MA use disorder; evidence for a dose-response effect was gained. They recommend clinicians to practice caution when titrating antipsychotic dosage from lower to higher doses to avoid EPSE in patients with MA use disorders.