BackgroundDrug‐induced life‐threatening ventricular arrhythmias including torsade de pointes (TdP), ventricular tachycardia (VT), and ventricular fibrillation (VF) are serious cardiac side effects. Psychotherapeutic drugs are known to be risk factors for arrhythmias. The aim of this study was to evaluate psychotherapeutic drugs associated with life‐threatening ventricular arrhythmias using the Japanese Adverse Drug Event Report (JADER) database.MethodsFrom the JADER database (April 2004 to September 2022), cases of TdP, VT, VF, and QT prolongation in patients taking psychotherapeutic drugs as ‘suspected drugs’ were extracted. The adjusted reported odds ratio (aROR) was calculated to identify potential drugs involved in combined TdP/VF/VT or combined QT prolongation/TdP.ResultsOf the 4,530,772 cases reported, life‐threatening arrhythmia‐related adverse events were reported in 1760 cases (QT prolongation 1261, TdP 192, VF 108, VT 199) among 909 patients; 58.9% of patients were female, and the highest incidence was among patients aged 80–89 years (18.6%), followed by patients aged 70–79 years (15.4%). The highest aROR for TdP/VF/VT was found for trazodone (17.1), followed by sulpiride (10.8), haloperidol (9.8), donepezil (9.1), and fluvoxamine (7.9). The highest aROR for QT prolongation/TdP was found for guanfacine (87.8), followed by sultopride (60.1), escitalopram (21.0), trazodone (12.8), and donepezil (9.3).ConclusionsThis study showed that typical antipsychotics, antidepressants, and antidementia drugs were associated with life‐threatening arrhythmia‐related adverse events in a Japanese clinical setting. These events were more frequent in women and elderly individuals.