Suicide Rates and Subgroups With Elevated Suicide Risk Among Patients With Psychiatric Disorders: A Nationwide Cohort Study in Korea.

backgroundDespite the distinctly high risk of suicide among patients with psychiatric disorders, little is known regarding the nationwide rates and risk factors for suicide among individual subgroups of patients with psychiatric disorders. This study aimed to assess differences in suicide rates and identify risk factors for suicide across multiple psychiatric diseases using data from a nationally representative cohort in Korea.

methodsSix groups of incident patients with psychiatric disorders, namely those with drug use disorder (DUD), alcohol use disorder (AUD), schizophrenia (SCZ), bipolar disorder (BD), depressive disorder (DD), or other affective disorders (OADs), were extracted from the National Health Information Database and followed up. Suicide rates and risk factors were then determined for each disease group.

resultsPatients with psychiatric disorders had higher suicide rates than did the general population, with standardized mortality ratios (SMRs) ranging from 2.5 to 16.6. In particular, patients with DUD showed markedly higher suicide rate (584.0 per 100,000 person-years [PYs]; SMR, 16.6) than did patients with affective disorders, including DD (119.8 per 100,000 PYs; SMR, 3.1). AUD, DUD, SCZ, and BD showed lower male/female suicide rate ratios (1.1-1.4) than did depressive and OADs (2.2-2.4). Old age increased the risk for suicide among those with DUD and OADs, while medical aid recipients exhibited the lowest suicide risk among those with the AUD and SCZ. Male sex and the presence of multiple psychiatric comorbidities were consistently identified as suicide risk factors across mental illness subgroups.

conclusionThe current study observed substantial variations in suicide rates and risk factors across psychiatric disorders and patient characteristics, which have significant implications for suicide prevention strategies.