Substance use disorders and the risk of suicide mortality among men and women in the US Veterans Health Administration

Abstract

Background and aims: Limited information is available regarding links between specific substance use disorders (SUDs) and suicide mortality; however, the preliminary evidence that is available suggests that suicide risk associated with SUDs may differ for men and women. This study aimed to estimate associations between SUDs and suicide for men and women receiving Veterans Health Administration (VHA) care.

Design: A cohort study using national administrative health records.

Setting: National VHA system, USA.

Participants: All VHA users in fiscal year (FY) 2005 who were alive at the beginning of FY 2006 (n = 4 863 086).

Measurements: The primary outcome of suicide mortality was assessed via FY 2006-2011 National Death Index (NDI) records. Current SUD diagnoses were the primary predictors of interest, and were assessed via FY 2004-2005 VHA National Patient Care Database (NPCD) records.

Findings: In unadjusted analyses, a diagnosis of any current SUD and the specific current diagnoses of alcohol, cocaine, cannabis, opioid, amphetamine and sedative use disorders were all associated significantly with increased risk of suicide for both males and females [hazard ratios (HRs)] ranging from 1.35 for cocaine use disorder to 4.74 for sedative use disorder for men, and 3.89 for cannabis use disorder to 11.36 for sedative use disorder for women]. Further, the HR estimates for the relations between any SUD, alcohol, cocaine and opioid use disorders and suicide were significantly stronger for women than men (P < 0.05). After adjustment for other factors, most notably comorbid psychiatric diagnoses, associations linking SUDs with suicide were attenuated markedly and the greater suicide risk among females was observed for only any SUD and opioid use disorder (P < 0.05).

Conclusions: Current substance use disorders (SUDs) signal increased suicide risk, especially among women, and may be important markers to consider including in suicide risk assessment strategies. None the less, other co-occurring psychiatric disorders may partially explain associations between SUDs and suicide, as well as the observed excess suicide risk associated with SUDs among women.

Keywords: Alcohol use disorder; Veterans Health Administration; cohort; drug use disorders; substance use disorders; suicide.