Clinical course and demographic insights into suicide by self-poisoning: patterns of substance use and socio-economic factors.

Purpose: To analyze whether sociodemographic characteristics influence the substance choice and preclinical and clinical course of suicidal poisoning.

Methods: This was a retrospective single-center study in patients hospitalized due to suicidal poisoning and who received at least one psychiatric exploration during their inpatient stay. Patients' sociodemographic, anamnestic, preclinical, and clinical parameters were analyzed with respect to sex and age.

Results: 1090 patients were included, 727 (67%) were females, median age was 39 years (min-max: 13-91) with 603 (55%) aged 18-44 years. 595 patients (54.8%) ingested a single substance for self-poisoning, 609 (59.5%) used their own long-term medication. Comparing to males, females preferred antidepressants (n = 223, 30.7%, vs n = 85, 23.4%; p = 0.013) and benzodiazepines (n = 202, 27.8%, vs n = 65, 17.9%; p < 0.001); males more often used cardiovascular drugs (n = 33, 9.1%, vs n = 34, 4.7%; p = 0.005) and carbon monoxide (n = 18, 5.0%, vs n = 2, 0.3%; p < 0.001). Use of Z-drugs (n = 1, 1.7%, to n = 37, 33.3%; p < 0.001) and benzodiazepines (n = 4, 6.9%, to n = 33, 29.7%; p = 0.003) increased with age (< 18 to > 64 years), while use of non-opioid analgesics (n = 23, 39.7%, to n = 20, 18.0%; p < 0.001) decreased. Average dose of substance in patients > 64 years was 12.9 ± 18.4 times higher than recommended maximum daily dose (compared to 8.7 ± 15.2 higher in those aged < 18 years; p < 0.001). Males more often required intensive care (n = 150, 41.3%, vs n = 205 females, 28.2%; p < 0.001).

Conclusion: These results underline the complexity of (para-)suicidal poisonings and identify potential measures for their prevention, such as restricting access and better oversight over the use of certain substances.