Negative life events, alcohol use and suicides: A complex relationship

SUMMARY

Suicide is a global public health problem. Hence, understanding modifiable factors that precede suicidal behaviour is crucial. Research indicates that the time immediately preceding a suicide attempt differs from other periods in an individual’s life, highlighting the importance of identifying specific triggers. Previous studies have shown that interpersonal negative life events (INLEs) and alcohol use play a key role in contributing to suicidal ideation (SI) and suicide attempts. Alcohol consumption increases the likelihood of experiencing INLEs by impairing cognitive control and promoting risky behaviours, which in turn elevates the risk of stress-reactive suicide attempts. Additionally, individuals may resort to alcohol as a coping mechanism in response to INLEs, aligning with the tension-reduction theory, further reinforcing the cycle of distress and self-destructive behaviours. The bidirectional relationship between alcohol use and INLEs remains largely unexplored in the critical hours preceding suicide. Two potential moderators in this phenomenon could be (i) gender (alcohol consumption and use disorders are more prevalent amongst males, while females experience a higher frequency of INLEs), and (ii) alcohol use disorders. To better understand how these within-person processes contribute to suicide risk, it is essential to examine how chronic risk factors influence these proximal associations and whether they differ across key subgroups. Therefore, this study was planned to (i) study the temporal relations between acute INLEs and acute alcohol use in the 24 hours preceding suicide attempts, and (ii) explore biological sex and chronic alcohol use as potential moderators. A total of 151 individuals were recruited.¹

Participants were included in the study if they were 18 years or older, admitted within 24 hours of a suicide attempt, exhibited a clear intent to die, and provided informed consent to participate. Exclusion criteria included individuals with severe acute medical conditions, the presence of thought disorder symptoms such as hallucinations, or cognitive impairment that could interfere with their ability to engage in the study. Timeline follow-back for suicide attempts (TLFB-SA) and alcohol use disorders identification test (AUDIT) were used to assess the retrospective hourly INLEs and alcohol use. Separate hierarchical linear regression models (HLMs) were used to examine the bidirectional relationship between INLEs and alcohol use. Additional analyses accounted for autoregression as either of the two events could impact their own occurrence in the next hour.

The bidirectional relationship between INLEs and alcohol use in the period leading up to suicide attempts revealed important temporal dynamics. Acute alcohol use was a significant predictor of INLEs in the following hour. However, as the severity of chronic alcohol use increased, the strength of this association weakened, suggesting that individuals with long-term alcohol use may become less sensitive to the immediate effects of alcohol on their social interactions and stress responses. This underscores the need to consider both acute and chronic alcohol use patterns when assessing suicide risk. Sex had no significant association in this regard.

The impact of INLEs on alcohol use varied depending on statistical adjustments. In the univariable model without autoregression adjustment, experiencing an INLE significantly increased the odds of drinking in the next hour (odds ratio [OR]=2.64). However, after adjusting for autoregression, this effect was no longer statistically significant (OR=1.39), suggesting that prior drinking behaviour may play a stronger role in predicting subsequent alcohol use than immediate INLEs. Nonetheless, in a multivariable model estimated to understand the interactions, it was seen that the effect of acute INLEs on subsequent alcohol use was stronger in males than in females. However, this sex-based interaction became non-significant after accounting for autoregression. The interaction was not significantly moderated by chronic alcohol use either.

COMMENT

The study findings suggested that INLEs and acute alcohol use are interrelated, with the moderating effect of chronic alcohol use. It is commendable to see how the use of a single structured instrument, TLFB-SA, combined with robust statistical analysis can yield valuable insights into the complex phenomenon of suicide. While the study provides information about the proximal events of suicidal behaviour, some clarifications would have provided greater insights into the study. First, some information regarding the most important and sole data gathering instrument of the study, i.e. TLFB-SA, could provide more clarity. For instance, description of the events which did not fall in the already existing stimulus list, whether there was any gradation across different INLEs, whether any weightage was given to intrapersonal negative life events, substance use other than alcohol, current mood state, or frequency of suicidal thoughts. It remains unclear which modality was used for TLFB-SA (pen and paper or tablet/computer-based). The authors also mention that start- and stop-time was noted, but this data is missing in the results. While TLFB has shown good reliability and validity in various substance-use related behaviours in the existing literature,² assessing the test–retest reliability of the proforma could have strengthened the findings. Second, the choice of using a HLM was rightly made by the authors since lagged variables were used.³ However, we believe that HLM could have utilized only those participants/hours where INLEs and acute alcohol use were present (i.e. 50 individuals in the model predicting INLEs and 90 individuals in the model for predicting acute alcohol use). From the current article, the whole sample (N=151) was taken in the model when either of the two events was present in only 104 individuals. This could have downplayed or diluted the actual associations between the two events. Third, to study the moderating effects, sex and chronic alcohol use were considered, but some other important variables which could moderate or mediate the effect of INLEs on acute alcohol use and vice versa were not studied. We understand that all questions cannot be answered in a single study, but a mention of some important moderators, such as other psychoactive substances, mood state, physical pain, etc. could have found a place in the discussion section to pave the way for future research. Fourth, although primary aims did not include assessing suicidality and its correlates, it could have been described to some extent for better clarity for readers. A timeline follow-back on thoughts about suicide in the preceding 24 hours could be an important mediator/moderator, and its inclusion could have been considered in TLFB-SA. Finally, we would like to highlight some points noted while reading the discussion section. While authors mention that retrospective recall was addressed by taking participants soon after they were hospitalized, the limitations of physical pain, and a priority on the physical/surgical/medical care could also confound the recall.⁴

The study is particularly relevant in the Indian context since the suicide rate in India is even higher than the global average. Moreover, India’s contribution to global suicide deaths increased from 25.3% and 18.7% in 1990 to 36.6% and 24.3% in 2016 in women and men, respectively.^5,6 Most studies in India are on SI or suicide completers, with few on understanding the context of attempters. Further, suicide has multifactorial determinants ranging from biological to social and contextual, and it is imperative to understand this phenomenon in the Indian context. Despite the highlighted limitations, it is imperative to understand that the study brought out some novel aspects and understanding of the reciprocal relationships between two common yet understudied phenomena happening before a suicidal attempt.