Is suicide under the influence of alcohol a deliberate self-harm syndrome? An autopsy study of lethality

Abstract

Background: Alcohol is a risk factor for suicide and is often involved in violent actions. The aim of the study was to assess the involvement of alcohol in suicides and its relationship with the lethality of suicide methods.

Methods: In a retrospective study on autopsy reports, we compared suicide and non-suicide victims, suicides with positive and negative blood alcohol concentration (BAC), and studied the lethality of suicide methods using a multivariate analysis.

Results: Suicide victims (n=88) were not different to non-suicide victims (n=270) for positive BAC and narcotics, but were more often positive for prescription medications (59.1 vs. 35.6%, p=0.003) and medications in blood (72.7 vs. 54.8%, p=0.004). Whereas non-suicidal victims died mainly of traumas (60%, p<0.001), two populations of suicides emerged with regard to BAC, self-poisoning predominating with positive BAC (38.9%, p=0.039) and asphyxiation with negative BAC (41.4%, p=0.025). Positive BAC appeared as the unique and strong independent predictive factor, increasing the risk of self-poisoning suicide by 4.36 [1.29-14.76], and decreasing the risk of suicidal asphyxiation by 84% (OR=0.16 [0.03-0.83]). Positive blood narcotics tended to behave in the similar way to alcohol.

Limitations: Recruitment bias (victims declared by the Forensic authorities) and incomplete autopsy reports are the two main limitations.

Conclusions: Characteristics of suicide victims with positive BAC are suggestive of Deliberate Self-Harm Syndrome (low lethality methods, substance misuse). These being at high risk of repeated suicide attempts, previous self-harm involving alcohol may represent a warning sign and access to medication should be limited to prevent recidivism.

Keywords: Alcohol; Autopsy; Lethality; Self-harm; Suicide.