Background. Psychotic disorders, including schizophrenia (SZ), schizoaffective disorder (SZA), bipolar disorder (BD), psychotic depression (PD), and other nonaffective psychoses (ONAP), are associated with increased risk of suicidal acts. Few studies have compared suicidal act prevalence across psychotic disorders using both self-report and register data. The impact of hospitalization duration on subsequent suicidal acts is unclear.

Methods. We used data from the SUPER-Finland study, involving 7067 participants with register-based ICD-10 diagnoses of psychotic disorders (SZ, SZA, BD, PD, ONAP). Lifetime suicidal acts were identified through self-report and register-based records of intentional self-harm events requiring medical treatment. Associations between diagnostic categories and suicidal acts were assessed using logistic regression, adjusted for sex, duration of illness, socioeconomic status, childhood abuse, and substance use. Survival analysis was used to examine the impact of hospital stay length on postdischarge self-harm.

Results. Lifetime suicide attempts (39.1%) and register self-harm (19.3%) were prevalent. of those with self-reported suicide attempts, 40.5% also had register-based self-harm. Self-harm and suicide attempts were significantly more prevalent in SZA, BD, and PD compared to schizophrenia, with large differences between groups (24.1-46.4% for suicide attempts, 11.1-23.9% for self-harm). Adjusted odds of self-harm were higher for disorders with a mood component. Shorter hospitalizations were associated with an elevated hazard ratio for subsequent self-harm.

Conclusions. Prevalence of register-based self-harm and self-reported suicide attempts differ markedly. Suicidal acts are common in psychotic disorders, particularly in those with a mood component. Very short inpatient stays may not be adequate in these disorders.