Summary: Alcohol use disorder is linked to a substantial increase in suicidal thoughts among adults.
Source: University of Otago
New research linking harmful drinking to higher suicide risk has prompted calls to revise New Zealand’s national suicide prevention strategy.
A study from the University of Otago, Christchurch, published in the Australian and New Zealand Journal of Psychiatry, shows that alcohol use disorder—defined as alcohol abuse or alcohol dependence—is associated with a significantly higher likelihood of suicidal ideation in adults.
Led by Dr. Rose Crossin of the Department of Population Health, the research analyzed data from the Christchurch Health and Development Study (CHDS), a well-established birth cohort of 1,265 individuals born in 1977. Participants were interviewed in five waves between the ages of 18 and 40, providing repeated measures of alcohol use and suicidal thoughts over time.
Dr. Crossin explains that, before adjusting for common childhood and adult risk factors such as trauma, physical and mental health conditions, and other substance use, alcohol dependence nearly tripled the odds of reporting suicidal ideation. After controlling for these factors, the risk remained substantially higher—about 50% greater—among those with alcohol dependence.
The increased risk was observed across genders and ethnic groups, reinforcing findings from international studies that identify harmful drinking as a consistent risk factor for suicidal thinking. According to the authors, alcohol use disorder is among the most reliably established contributors to suicide risk and ranks behind major depressive disorder as a leading contributor to overall suicide burden.
The authors urge that these findings be taken seriously given New Zealand’s concerning rates of hazardous drinking and suicide. Ministry of Health reporting from 2020 indicated that around 21% of adults met hazardous drinking criteria, and coronial figures for the year to June 2021 recorded 607 deaths by suicide in New Zealand.
“The World Health Organization highlights harmful alcohol use as an important contributor to suicide, yet the current national suicide prevention strategy includes no targeted alcohol-related interventions,” Dr. Crossin says. “This evidence suggests the government should prioritize strong, evidence-informed actions to reduce alcohol-related harm and the associated suicide risk at both the population and individual levels.”
Professor Joe Boden, Director of the Christchurch Health and Development Study and co-author on the paper, notes that the CHDS data strengthen the study’s conclusions by allowing researchers to estimate the specific influence of alcohol problems on suicidal behavior while accounting for earlier life experiences.
“Many prior international studies recruited participants only after age 16 or relied on single-time assessments in adulthood, limiting their ability to adjust for childhood risk factors,” Professor Boden says. “In contrast, CHDS participants were interviewed five times before age 40, and the study includes detailed documentation of childhood exposures.”
The CHDS has collected a wide range of childhood measures that could help explain how alcohol problems relate to suicidal behavior. For this analysis, researchers selected childhood variables known to associate with both alcohol use disorder and suicide risk—factors such as family socioeconomic status, exposure to punishment, abuse or neglect, family history of criminal offending, and parental history of alcohol problems.
The study also incorporated adult indicators of adversity and life strain, including employment status, relationship instability, life satisfaction, internalising mental health disorders, and other substance use disorders, allowing for robust adjustment of time-varying adult covariates.
Dr. Crossin and Professor Boden report they are preparing a follow-up study that will use coronial data to investigate the prevalence and characteristics of acute alcohol use at the time of suicide in Aotearoa New Zealand.
About this AUD and suicide research news
Author: Press Office
Source: University of Otago
Contact: Press Office – University of Otago
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Original Research: Closed access. “The association between alcohol use disorder and suicidal ideation in a New Zealand birth cohort” by Rose Crossin et al., Australian & New Zealand Journal of Psychiatry.
Abstract
The association between alcohol use disorder and suicidal ideation in a New Zealand birth cohort
Background:
Alcohol use disorder is known to increase suicide risk, but multiple shared risk factors—both from childhood and adulthood—can confound this relationship. This study examined the longitudinal association between alcohol use disorder and suicidal ideation across adulthood while controlling for childhood background characteristics and time-varying adult covariates.
Method:
Researchers used data from the Christchurch Health and Development Study, a birth cohort of 1,265 children born in Christchurch, New Zealand, in mid-1977. Alcohol use disorder, operationalised as alcohol abuse and alcohol dependence, was assessed across five waves between ages 18 and 40. Suicidal ideation was measured during the same periods. The analysis adjusted for childhood confounders and for adult, time-varying covariates such as internalising disorders, distress from relationship dissolution, employment status, life satisfaction, and other substance use disorders.
Results:
Compared with no alcohol disorder, alcohol abuse alone was not significantly associated with suicidal ideation before or after adjusting for childhood and adult covariates. In contrast, alcohol dependence showed a robust association with suicidal ideation both before and after adjustment (unadjusted odds ratio = 2.89, 95% CI = [2.09, 3.99]; adjusted odds ratio = 1.52, 95% CI = [1.04, 2.23]). Alcohol dependence also remained significantly associated with suicidal ideation when directly compared with alcohol abuse (unadjusted odds ratio = 2.33, 95% CI = [1.61, 3.37]; adjusted odds ratio = 1.54, 95% CI = [1.00, 2.37]).
Conclusion:
This longitudinal analysis found that alcohol dependence is associated with increased suicidal ideation in a New Zealand birth cohort, and this association persists after accounting for childhood confounding and adult covariates. Given New Zealand’s high levels of heavy drinking and suicide, national and regional suicide prevention plans should include strategies to reduce risky alcohol consumption at individual and population levels, as alcohol dependence represents a modifiable risk factor for suicide.