We retrieved 8548 references until February 2015, including 6658 references through searching electronic databases, 1890 references through checking other sources, including reference lists, relevant web sites, or personal contact with authors of the included studies. We excluded 8380 duplicates and clearly irrelevant references through reading titles and abstracts. Of the 168 references considered potentially eligible after screening, 137 studies were excluded because they were not original article (i.e., letter, commentary, review) or did not meet the inclusion criteria (Fig 1). Eventually, 31 studies included in the meta-analysis, including 9 cohort studies 23–31 and 10 case-control studies 32–41 and 12 cross-sectional studies 42–53.
Study sample
- Since 2001, past-year prevalence of high-risk drinking has increased by 29.9%, and alcohol use disorder (AUD) by an alarming 49.4% 21.
- Wolk-Wasserman 222 found that the suicidal hints or threats were usually not taken seriously by the partners of those with alcohol dependence, even when suicide had been attempted previously.
- Indeed, estimates of lifetime suicide attempt rates among individuals with OUD are gravely elevated, ranging between 17% and 48% 143,144,145,146,147,148,149,150,151,152.
- Suicide claims more than 800,000 lives each year worldwide and is the second-leading cause of death among people ages 15 to 29.1 For every suicide, at least 20 nonlethal suicide attempts have occurred, primarily by attempted overdose.
- Antisocial traits and substance abuse (including alcohol abuse) are strongly connected to suicide.
In the latter study, the lowest levels of CSF-5HIAA were found in impulsive offenders with a past suicide attempt, perhaps suggesting that impulsivity and suicidality are independently and additively related to serotonergic dysfunction. The exposure of interest was AUD including alcohol abuse and alcohol dependence 14. AUD is a condition characterized by the harmful consequences of recurrent alcohol use and physiological dependence on alcohol resulting in harm to physical and mental health and impairment of social and occupational activities 15. The studies addressing the association between AUD and suicide among drug abusers or among patients with mental disorders were excluded. Further research is needed to examine specific subgroups at higher risk of suicide and to compare attempted suicides with completed suicides, to develop alternative risk-profiles and to devise intervention strategies that are robust enough to account for social and cultural differences. Suicide is a major public health problem and must be given high priority with regard to prevention and research.
Alcohol and opioid use disorders (AUD/OUD) significantly increase risk for suicidal ideation, attempts, and death, and are the two most frequently implicated substances in suicide risk. We provide a brief overview of shared risk factors and pathways in the pathogenesis of AUD/OUD and suicidal thoughts and behaviors. We also review clinical recommendations on inpatient care, pharmacotherapy, and psychotherapeutic interventions for people with AUD/OUD and co-occurring suicidal ideation and behavior. Universal preventive interventions are directed to the entire population, selective interventions target people at greater risk for suicidal behavior, and indicated preventions are targeted at individuals who have already exhibited self-destructive behavior.
We found evidence of a linear association between total AUDIT score and suicide attempt, suicidal thoughts and non-suicidal self-harm in a representative English general population sample. Our analyses suggest that where alcohol use significantly disrupts day-to-day functioning, this may underpin the relationship between alcohol use and suicide-related outcomes to a greater extent than higher alcohol consumption. Alcohol use disorder has an enormous impact on relationships, generating ambivalence and anger.
Reviewing the literature for the period 1991–2001, Cherpitel, Borges, and Wilcox 88 found a wide range of alcohol-positive cases for both completed suicide (10–69%) and suicide attempts (10–73%). Several case-control studies at the individual level have shown a high prevalence of alcohol abuse and dependence among suicide victims 89,90. Kolves et al. in a psychological autopsy study reported that 68% of males and 29% of females who committed suicide met the criteria for alcohol abuse or dependence 89. Strong support for a direct link between alcohol and suicide comes from aggregate-level data. Both longitudinal and cross-sectional aggregate-level studies usually report a significant and positive association between alcohol consumption and suicide 91–93. Norstrom 94 reported that the estimated alcohol effect was stronger in Sweden (13% per liter) than in France (3% per liter).
The Alcohol-Suicide Link: A Bond Difficult to Disentangle
Ethanol-induced NMDA inhibition in the cerebral cortex results in the reduction of noradrenaline and acetylcholine 136, and this might be related to the development of depression. This has been proposed as an explanation of the association between alcohol and depression, but may be also relevant to suicide. Glutamate in the cerebellum increases the levels of BDNF via NMDA, and this in turn reduces apoptosis. Ethanol decreases the effect of glutamate on BDNF 137 and may thus indirectly be related to the increased apoptosis and movement disorder found in chronic alcoholism.
A Closer Look at Substance Use and Suicide
However, there is a dearth of research evaluating their effectiveness in co-occurring suicidality and AUD. Further research is needed to understand the effects of alcohol and opioid use on suicide risk, as well as address notable gaps in the literature on psychosocial and pharmacological interventions to lower risk for suicide among individuals with AUD/OUD. Suicide is one of the top 20 leading causes of death in the world for all ages 1, the third leading cause of death among people aged 15–44 years, and the second leading cause of death among people aged 10–24 years 2. These numbers underestimate the problem and do not include suicide attempts which are up to 20 times more frequent than completed suicide 2. Intervention should help people find a motivation to stop drinking, identify the circumstances that motivate them to drink, identify the factors that engender this conduct, and evaluate the possible risk of suicide.
They based their definitions on the presence or absence of suicidal intent and the presence or absence of injury. They purposely avoided adding a third domain of Alcohol Withdrawal lethality (or degree of injury) because currently there is a lack of consensus for defining lethality. According to this classification, suicide is a fourth order event in a set where the first order (i.e., the name of the set) is represented by Self-Injurious Thoughts and Behaviors. Subsets of the set are risk-taking thoughts and behaviors and suicide-related thoughts and behaviors.
Suicide Risk and Addiction: The Impact of Alcohol and Opioid Use Disorders
Suicidal behavior usually occurs early in the course of mood disorders, but only in the final phase of alcohol abuse when social marginalization and poverty, the somatic complications of alcoholism and the breakdown of important social bonds have taken over. Thus, the relationship between alcohol abuse and depression in determining suicidality is complex and multifaced, and there are many factors which may impact on suicidality in depressed patients. Taken together, these results remain highly suggestive, but not conclusive, for a neurobiological link between alcohol misuse and suicidal behavior. Altered glutamatergic receptors in the brains of people who died from suicide comprise reduced NMDA receptors 170 and increased caudate metabotropic receptors 171. These findings are interesting in pointing to alcohol-suicide commonalities in neurochemical alterations but, unfortunately, these post-mortem findings in the brains of suicides are only partially matched by alterations found in brains of non-suicidal people with chronic alcoholism.
Scores for these three variables were summed to give a score for harmful effects of drinking, ranging from 0 to 10. Suicide prevention is primary with respect to alcohol use, but must take into account the alcohol abuse especially in cases where the alcohol use facilitates suicide behavior. Additionally, cognitive constriction (narrowed attention which reduces perceived potential solutions to a dichotomy—finding an immediate solution or committing suicide) is frequently observed prior to a suicide attempt 178. Alcohol produces cognitive constriction through alcohol myopia 179, and this process has been confirmed by research showing that inhibition conflict (weighing pros and cons and identifying alternative solutions) mediates the relation between intoxication and social behavior 180. Silverman et al. 31 revised O’Carroll’s nomenclature, focusing on suicide-related ideation, communication and behavior.