(PS9-8) Investigating the Role of Substance Use in Decisions to Attempt Suicide: A Mixed Methods Study of Recent Suicide Attempts Made by Army Soldiers

This study offers potential mechanisms that can help us understand how and why substance use increases suicidal risk and behavior. 

Suicide is a leading cause of death worldwide, and suicide rates have not declined despite ongoing research. Although historically low, suicide rates among Army soldiers have recently risen and remain elevated, underscoring the urgent need to identify contributing factors. It is well documented that substance use significantly increases the risk of attempting and dying by suicide in both military and civilian populations, yet we lack a precise understanding of how and why substance use confers increased risk. 

Qualitative research can offer valuable insights into difficult-to-observe phenomena, such as the role of substance use in suicidal behavior. However, few studies have explored this topic, and even fewer have interviewed suicide attempt survivors to examine how factors like substance use influenced their decisions.  

We hypothesized that substance use may increase risk of suicidal behavior by increasing disinhibition and impairing judgment, thereby increasing the likelihood or capacity to engage in atypical behaviors, such as suicide. 

To investigate this, we analyzed qualitative and quantitative data from 21 soldiers who reported being under the influence of an intoxicating substance during their suicide attempt. These participants were from a larger study of 89 Army soldiers who completed semi-structured, in-depth interviews during hospitalization following a suicide attempt.  

We analyzed interviews using directed content analysis and a grounded theory approach. We also used inferential statistics (chi-square test) to test whether results differed by gender. 

Results revealed two roles of substance use in suicide attempts based on awareness and intent: (1) intentional intoxication, where individuals knowingly used substances to disinhibit or facilitate their actions, and (2) unintentional intoxication, where individuals were seemingly unaware of how the substance would impact their behavior and found themselves unexpectedly acting on suicidal thoughts. Mapping onto these roles, substance use influenced suicidal behavior through two mechanisms: (1) facilitation, increasing courage and motivation to attempt, and (2) disinhibition, impairing judgment and reducing impulse control. Among men, 24.6% (17/69) reported being intoxicated at the time of their attempt, compared to 20% (4/20) of women. A chi-square test found no significant relationship between genders, χ²(1, N = 89) = 0.02, p = .90.  

These findings contribute to our understanding of how substance use influences decision-making in suicidal behavior. The distinction between intentional and unintentional use offers insight into how individuals' awareness of state-dependent cognitive effects (how altered states impact thinking and behavior) may increase suicide risk. Wherein individuals with greater awareness may intentionally use substances to facilitate suicide, while those with less awareness may do so unintentionally because of intoxication. Future research should confirm these mechanisms and identify individuals most vulnerable to substance-induced suicidal behavior.