Lessons to be learned: identifying high-risk medication and circumstances in patients at risk for suicidal self-poisoning

Background Although the total number of suicides decreased since the beginning of the 1980s, the number of suicide-related behaviors using self-intoxication increased. Therefore, research on the characteristics of individuals committing self-intoxication becomes of growing importance for risk assessments and the development of preventive measures. Methods In this prospective, observational, monocentric cohort study, all incoming calls at our Poisons Control Centre reporting suicide-related behaviors through self-intoxication, were analyzed via a standardized questionnaire over 12 months. Both univariate and bivariate analyses were performed. Results 1238 cases of deliberate intoxication were included in the study. The majority of cases occurred in the age group between 18 and 44 (n = 607/49%), two-thirds were female (n = 817/66%). The main substances used were antidepressants (n = 420/34%), peripheral analgesics (n = 322/26%) and neuroleptics (n = 282/23%). The majority of patients ingested substances from their prescribed medication (n = 640/82%) with the highest proportion in those aged over 64 years (n = 72/113; 91%, p < 0.001). Substance use was reported for the minority of patients (n = 175/23%). For 704 cases (79%), a psychiatric disorder was documented. Factors associated with recurrent suicide-related behaviors were an underlying psychiatric disorder (OR = 6.2; 95% CI 3.8–10.4), substance use (OR = 2.4; 95% CI 1.5–3.8), and ingestion of neuroleptics (OR = 2.1, 95% CI 1.4–3.0) or antidepressants (OR = 1.6; 95% CI 1.2–2.3). Conclusion This study might contribute to identifying individuals with an increased risk of suicide-related behaviors by deliberate intoxication and to developing preventive strategies for future suicide attempt(s).