What is the drug most often used by individuals who successfully complete suicide?

The most commonly used drug by individuals who successfully complete suicide is barbiturates. Barbiturates are central nervous system depressants that can lead to respiratory depression, coma, and death when taken in toxic doses. Historically, these drugs were more readily available and were often prescribed for anxiety and sleep disorders before the introduction of safer alternatives and stricter regulations. The lethality of barbiturates in overdose situations contributes to their association with completed suicides.

While other substances like alcohol and opioids are also linked to suicidal behavior, they are more often associated with attempts rather than completions. Alcohol can impair judgment and increase impulsivity, which might lead to a higher incidence of suicide attempts but not necessarily completion. Opioids, while they can be lethal in overdose situations, are more commonly involved in accidental overdoses rather than planned suicides. SSRIs are generally used as antidepressants and have a protective factor against suicide in many patients, which makes them less likely to be associated with completed suicides. Thus, the prevalence and lethality of barbiturates in overdose protocols underscore their association with completed suicides.