Drugs age-of-onset as a signal of later post-traumatic stress disorder: Bayesian analysis of a census protocol.

Individuals with PTSD have an increased risk of drug use disorders. Conversely, we aim to evaluate how early onset of alcohol, tobacco and psychoactive drugs use are associated with PTSD later in life. 2,193 brazilian young adults completed modularized assessments: The Trauma History Questionnaire, Post-Traumatic Stress Disorder Checklist-Civilian Version (PCL-C, transformed to PCL-5 through a crosswalk procedure), the Barratt Impulsivity Scale; and a survey on drug use with self-report questions about first use, current use, frequency, quantity, and interpersonal consequences.