Passive suicide ideation in major depressive disorder: prognostic role and effect of antidepressant treatment

Background and aims: Passive suicidal ideation (PSI)—defined as the desire to die without any intent to act—is a relatively understudied phenomenon. This study investigated its prognostic role in major depressive disorder (MDD) and its evolution during antidepressant treatment. Methods: A total of 482 outpatients (30 % male; mean age = 43.14 ± 12.46 years) from the CO-MED trial were included. Clinical evaluations were conducted at baseline and again after 6 weeks, assessing depressive and hypomanic symptoms, comorbid anxiety, and childhood trauma. PSI was measured using four targeted items from the Concise Health Risk Tracking Self-Report scale (CHRT_PSI; score range 0–16). To distinguish PSI from related depressive symptoms such as hopelessness, a conservative threshold (CHRT_PSI ≥5) was used when analyzing clinical features and treatment response. A broader, more sensitive threshold (CHRT_PSI ≥4) was applied when evaluating PSI's predictive accuracy for suicidal behavior. Results: Compared to patients without PSI, those in the PSI group (n = 283; 59 %) exhibited more severe depressive symptoms, higher rates of comorbid anxiety disorders, and more childhood traumas, including both physical and emotional abuse. While PSI showed modest overall accuracy (37 %–46 %) in predicting suicidal behavior, its sensitivity (66 %–85 %) and negative predictive value (78 %–89 %) were good. PSI was also a significant predictor of response to antidepressants, an effect that remained robust even after adjusting for age, sex, depression severity, and history of childhood maltreatment. Among the 270 PSI patients who completed 6 weeks of treatment, 96 achieved remission from PSI. Insomnia and anhedonia were associated with poorer outcomes, while talkativeness was linked to a higher likelihood of remission. Conclusion: PSI is common in individuals with MDD and is associated with a worse prognosis. Insomnia may act as a barrier to PSI remission during treatment.