Exposure to traumatic events, PTSD, and alcohol use: A comparative study in Japan by type of traumatic event and gender.

Aim: The association between alcohol use disorder (AUD) and posttraumatic stress disorder (PTSD) is well established. However, many studies in Japan have focused on trauma related to natural disasters, which differ from international studies that include several trauma types. We examined whether trauma exposure and PTSD are associated with AUD risk across diverse trauma types. Additionally, because gender differences in drinking patterns and AUD may vary by country, we explored whether findings from international research hold in a Japanese context. Methods: An online survey of 6180 Japanese adults included 25 items from the World Health Organization's traumatic event list, the PTSD Checklist-5, and the CAGE Questionnaire. Of these, 5150 reported exposure to traumatic events, and 1030 reported no exposure. Results: Participants' mean age was 43.79 years, and 52.8% were women. The AUD group comprised more men (59.1%) than the non-AUD group (44.1%). Logistic regression analyses showed that trauma exposure was associated with higher odds ratios (ORs) of AUD among individuals without PTSD (OR = 1.55, 95% confidence interval [CI]: 1.24-1.94) and among those with PTSD (OR = 2.02, 95% CI: 1.62-2.52) compared to those with no trauma exposure. Among women, several non-natural-disaster events showed a higher risk of AUD than that posed by natural disasters. In men, physical violence by a partner was associated with a higher risk. Conclusion: These findings highlight the pertinence of assessing trauma characteristics and gender when addressing PTSD and AUD. They may inform gender-sensitive interventions and culturally relevant policies targeting individuals at risk for comorbid PTSD and AUD.