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

Abstract

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).