Psychoactive substances use before suicide: detailed analysis of all cases that occurred in the Brazilian Federal District in a 10-years period

BACKGROUND: Psychoactive substances (PASs) are an important risk factor for suicide. This study investigated the sociodemographic characteristics, data related to the suicidal behavior, the methods employed, the circumstances of the events, and the use of PASs before dying in all suicides that occurred between 2005–2014 in the Brazilian Federal District, comparing cases with positive and negative detection for PASs in the post-mortem analysis to identify groups at greatest risk. METHODS: A population-based, observational, cross-sectional study with an analytical aspect was conducted with suicides cases collected from local police, which toxicological examination was performed (headspace gas chromatographic-mass spectrometry-HS-GC/MS) for detection of ethanol and methanol in blood samples; immunoassay for other substances (cocaine, marijuana, benzodiazepine). RESULTS: The results showed that the increase in the suicide rate was 10 × greater than the population growth, and 44% of the individuals used PASs before suicide. Individuals are more likely to die by suicide at home, be male, have tried before, and change their behavior days before death; they choose to hang as the method and are influenced by alcohol. CONCLUSION: Identifying what sociodemographic characteristics are associated with a fatal suicide attempt among individuals who use PASs and those who do not use and those who have/do not have mental disorders and what methods are employed could be employed as a path to better interventions. Thus, prevention actions could be planned and directed to individuals with greater risk. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12888-022-04082-z.