Alcohol use disorder and non‐fatal suicide attempt: findings from a Swedish National Cohort Study

Abstract

Background and Aims Alcohol use disorder (AUD) is associated with increased risk of non‐fatal suicide attempt. We aimed to measure the strength and mechanistic nature of the association between AUD and increased suicide attempt and determine any causal pathways and/or shared risk factors. Design We used Cox proportional hazards models in population‐level and co‐relative analyses to evaluate the risk of first non‐fatal suicide attempt as a function of previous AUD. Setting and Participants We used continuously updated longitudinal nationwide Swedish registry data on native Swedes born from 1950 to 1970 (n = 2 229 619) and followed from age 15 until 2012. Measurements AUD and suicide attempt were identified using International Classification of Diseases (ICD)‐8, ICD‐9, and ICD‐10 codes. AUD was also identified using pharmacy and criminal records. Genetic and family environmental risks were derived based on relatedness via the Multi‐Generation Register and shared residency via the Population and Housing Census and the Total Population Register. Findings AUD was robustly associated with suicide attempt in crude models (hazard ratio [HR] = 15.24 [95% CI: 14.92, 15.56]). In models adjusted for sociodemographic factors and psychiatric comorbidity, the association was attenuated: for women, HRs declined gradually across time, ranging from 5.55 (3.72, 8.29) during the observation period that ranged from age 15 to 19 years to 1.77 (1.65, 1.90) at age 40 or older. For men, the corresponding figures were 6.12 (4.07, 9.19) and 1.83 (1.72, 1.94); in contrast to women, risk of suicide attempt among men increased from age 15 to 29 before declining. In co‐relative models, a residual association remained, consistent with a causal path from AUD to suicide attempt. Conclusions In Sweden, alcohol use disorder appears to be an important predictor of suicide attempt even in the context of other psychiatric disorders. The observed association is likely the result of features that jointly impact risk of alcohol use disorder and suicide attempts (genetic liability, psychiatric illness, and childhood stressors) and a potentially causal pathway, acting independently or in conjunction with one another.

Roles of alcohol use disorder and resilience in risk of suicide attempt in men: A Swedish population‐based cohort

“…The current results support previous findings by highlighting a strong association between AUD and suicide attempt (Agrawal et al, 2017; Darvishi et al, 2015; Edwards et al, 2021b; Lee et al, 2019). Additionally, we considered the role of resilience, confirming its inverse association (i.e., potentially protective role) with suicide attempts (Liu et al, 2014; Nyberg et al, 2020).…”

“…Our co‐relative analyses indicate that the strength of the associations of AUD and resilience with suicide attempt decreases as we account for greater levels of familial liability, underscoring the potential impact of shared latent genetic and family environmental influences. This is consistent with prior studies, showing that both genetic and rearing effects are important in the transmission of suicide attempts (Kendler et al, 2020), and more precisely that the association between AUD and suicidal behaviors (Edwards et al, 2020, 2021b) decreased when familial confounding factors were accounted for. Importantly, these associations remain significant (i.e., HR estimates and CIs do not include 1), supporting a possible causal pathway in which AUD and resilience would directly predict suicide attempt.…”

“…Thus, further knowledge regarding the role of resilience in moderating risk, especially among those with AUD, could be enhanced by the evaluation of the role of familial factors. We have recently applied co‐relative analyses to explore the association between AUD and both suicide attempt (Edwards et al, 2021b) and suicide death (Edwards et al, 2020). We found that it is due to both shared genetic and environmental liability and a potentially causal relationship with some differences across outcome (attempt vs. death).…”

Commentary on Edwards et al.: Alcohol use disorder—a different impact in young adulthood than later?

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It could be that alcohol use and lower capacity for emotional control among young people jointly impact upon the risk of suicide attempts. This is a hypothesis that might follow from Edwards et al's study [1] and previous research. Thoughtful use of register data can give results of great value, but rarely unambiguous answers.

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“…At what age does a risk factor matter most? These are two issues that Edwards et al touch upon in their study of alcohol-use disorder (AUD) and non-fatal suicide attempt [1].…”