According to the World Health Organization (WHO, 2019), approximately 800,000 people die each year by committing suicide(1). Alcohol has always occupied an important place in human history, and the numbers speak for themselves: at least 90% of people occasionally drink alcohol at some point in their lives, and 30% or more of the drinkers will later develop problems related to its consumption(2). Suicide is a public health problem, and alcohol abuse, through disinhibition, impulsivity and impairment of judgment, can be a way to alleviate the suffering.
Global alcohol consumption is increasing, with a higher prevalence in developing countries(3,4). Both acute ingestion and addiction increase the risk of an impulsive suicide attempt, even in patients without depression(5). Therefore, there is a close relationship between these two complex phenomena, in which other factors also participate(3). Approximately 80 years ago, the concept of addiction itself was specified by Menninger both as a type of chronic suicide and as a contributing factor in deliberate self-harm(6).
Alcohol consumption can precipitate suicide by providing the impulse or the courage that these people need to complete a plan, a case in which the decision is highly alleviated by alcohol. In other cases, when rational judgment is affected and disinhibition occurs, suicide may seem a reasonable decision to the person concerned(7). At the same time, it has been observed that those who consumed alcohol before their time of death often chose a more lethal method of suicide, such as firearms(8).
The risk of suicide is higher in people with depression, especially when there is noncompliance or resistance to psychotropic drug treatment and, when combined with chronic ethanol consumption, it is even more dangerous. Most attempts took place in the context of a combination between impulsivity caused by alcohol abuse and depression, both occurring simultaneously in 85 out of 100 patients who managed to commit suicide(9).
Risk factors associated with suicide and alcohol use disorders
In the literature, it is often stated that people who have died following a suicide attempt, or who had a history of alcohol consumption, also had a history of multiple suicide attempts and defective family relationships. They have also witnessed a multitude of violent acts and their level of aggression was increased, compared to those who attempt suicide, but who did not have a history of alcohol consumption(10-12). Based on psychological autopsy studies, the results suggest that alcohol use disorder is widespread in people who commit suicide. They also reveal that a potent risk factor for suicidal activity is alcohol use disorder(13).
Risk factors for suicide, in the case of those who are addicted to alcohol, are represented by behavioral disorders, interpersonal conflicts, reduced tolerance to anger, contradictory family circumstances or an older age(10,14-16). When combined and then linked to personality traits or mental illness, these can escalate the way people act in certain circumstances or situations, especially when it comes to suicidal behavior(17). Also, major depressive disorder, bipolar disorder and borderline personality disorder or post-traumatic stress disorder are especially associated with suicidal behavior in people with addictive problems(18-23).
It was found that men had a higher suicide rate compared to women, in a study in which the authors investigated 204 suicide cases, trying to find similarities and differences between women and men. Three ways in which men differed from women were observed. They used more aggressive and lethal approaches, they were three times more likely to be drug users, and they were more concerned with economic issues than women. The authors concluded that differences of the suicide rate seen in men and women need a complex determination, but the most important notice would be that more men compared to women intend to commit suicide(24). Moreover, women are more vulnerable to developing side effects from alcohol consumption than men(2,25,26).
The COVID-19 pandemic has had an overwhelming impact on humanity in the past year, affecting over 100 million people around the world. The prevalence of unhealthy alcohol use and suicide attempts within the population has subsequently increased by adjusting individuals to the changes brought on by this epidemic, such as loneliness, working from home or even loss of employment. Social distancing and quarantine have caused increased feelings of disconnection and have affected the individual by increasing the perception of social pain(27,28). Depression is included among the mental and neurological manifestations of COVID-19 and, also, this new infectious disease exacerbates the preexisting mental conditions. There are high levels of stress and anxiety among the population which is susceptible to depression and risk behaviors(29-31). People who have previously abstained from alcohol are also at an increased risk of recurrence. When this happens, personal failure associated with other changes brought by the pandemic increase the recurrent thoughts of death in vulnerable people. Moreover, under the influence of alcohol, the danger of an impulsive suicidal gesture is high within the population(32).
What are the most common psychiatric disorders associated with alcohol use disorders?
Delusions and delirium, memory and sleep disturbances that arise during intoxication or withdrawal, as well as anxiety, mood and psychotic disorders, dementia and sexual dysfunction are all examples of alcohol-induced disorders(3).
Depression, anxiety and personality disorders are the most common psychological disorders associated with alcohol dependency. Typically, depression is secondary to alcohol dependency(33). The severity of mood disorders varies depending on the amount of alcohol ingested. It also depends on how long this behavior persisted, as well as the time of the last consumption. The individual’s vulnerability is important in the development of psychiatric symptoms in the context of excessive ethanol consumption(34). Alcoholism can complicate or mimic almost any medical symptom encountered in psychiatry, often making it difficult to diagnose the essence of the psychiatric complaints(35). In alcohol use disorders, heavy drinking is frequently associated with a 40% risk of depressive episodes, related with suicidal ideas and attempts, increased anxiety and insomnia(36).
Population studies have found that people with anxiety disorder are two to five times more likely to have problems regarding alcohol or opioid usage, compared to those without anxiety disorder(37). Severe anxiety disorders increase the risk of suicide attempts in people with mood disorders(38).
People with alcohol-induced disorders consume high amounts of alcoholic beverages, and high blood alcohol levels are associated with impaired judgment and increased disinhibition. Moreover, in addition to depressive moods and suicidal ideation, impulsive behaviors with self-harm attempts can be a real danger to patients(39). Psychopathological studies have shown that alcohol consumption and depression coexist. People with mood disorders may resort to ethanol consumption to be able to fight negative feelings. Initially, symptoms can be minimized by ethanol consumption, but in the long run, alcohol use can be addictive, and this exacerbates depressive symptoms(40). Studies have shown that depression and anxiety may be the only clinical symptoms of severe somatic pathology(41-43). Therefore, when encountering an alcoholic patient who presents with both depression and suicidal ideation, an organic cause should be considered, in addition to a toxic one. Patients who associate somatic pathology with feelings of guilt can develop severe psychotic depression, with an aggravating prognosis of the disease(44).
The neurobiology of suicide attempts and alcohol use disorders
Suicide is a major cause of death in the world, being one of the main three causes of death in people aged between 15 and 34 years old(45). Almost every case is a complication of a psychiatric condition, 90% of the people who resorted to this gesture had a serious mental illness, the most reported being mood disorders (about 60% of cases), of which depressive disorder was the most common(15). Other conditions include schizophrenia, alcoholism, substance abuse, personality disorders, epilepsy, obsessive-compulsive disorder and body dysmorphic disorder(46-57). About 22% of suicide deaths are attributed to ethanol consumption(1).
There is evidence that suicidal behavior can result from the activity of three neurobiological systems: hyperactivity of the noradrenergic system, changes in the normal function of the serotonergic system, and increased activity of the hypothalamic-pituitary-adrenal axis(58,59).
When speaking about suicide, major depressive disorder and alcohol use disorder, serotonin neurotransmitter deficits are identified(60). In the brain of the suicidal decedents and the cerebrospinal fluid of non-fatal suicide attempts(61,62), suffering from a major depressive disorder and alcohol disorder, impaired serotonin neurotransmission was observed(60,63,64). The reduced activity of this hormone is also associated with increased aggression and impulsivity, traits that are more likely to lead to suicidal behavior(65,66). It should also be noted that, in the suicide attempts with severe depression, schizophrenia and personality disorders, the low cerebrospinal fluid concentration of 5-hydroxyindoleacetic acid has been documented, similar to individuals who do not attempt suicide but have the same psychiatric diagnosis(46).
In response to the reduced serotoninergic transmission, alcoholic suicides can fail to up-regulate ventral prefrontal 5-HT1A receptors, raising the risk of suicidal actions. Only suicide attempts suffering from alcoholism have been found to have low binding capacity in the serotonin transporter, indicating a link to suicide. In alcoholic patients, lesser 5-HT1D terminal auto-receptor binding supports impaired serotonergic innervation related to alcoholism(3).
In literature, it is stated that the genetic abnormalities in the dopaminergic system are related to pathological aggression(67). Self-directed pathological aggression can also be considered suicidal behavior. Furthermore, dopamine deficiencies have been shown to be associated with impulsiveness, mental dysregulation and alcohol use disorders(68). In patients diagnosed with depression with a history of violent or non-violent suicide attempts, lower levels of the homovanillic acid were detected in the cerebrospinal fluid, compared to the control groups(69). High aggression, impulsivity and suicidal tendencies are also associated with alcoholism(70,71).
It is, therefore, rational to conclude that the genetically determined dopaminergic dysfunction can play an important role in the suicidal behavioral pathophysiology of alcoholism(72-74). In patients diagnosed with psychotic depression who have committed suicide, there is a decrease in the level of dopamine described in the literature. In the field of biomarkers, new advances have been made, including a new scientific research direction with implications for dopamine treatment using voltammetric techniques on electrodes of different types, with the scope of the rapid determination of the biological fluids and active type components in various pharmaceutical formulation (benserazide and L-DOPA)(75,76).
The most common mood disorders in patients with chronic ethanol use are depressive disorders and bipolar disorders. It is important to detect as early as possible both the mood changes and the pathologic alcohol consumption, to correctly conduct the management of the patient, to reduce the suicide risk and to prevent suicide attempts. Screening for alcoholism associated with depression is important not only for the improvement of quality of life, but also for the early detection of these diseases, which can reduce the costs of health services and economic damages. A significant percentage of people who intend or commit suicide have an increased consumption of alcoholic beverages.
All patients with alcoholism should, however, be assessed for the possibility of suicide. Awareness of the risk and susceptibility of alcoholism culminating with suicidal actions still outweighs our perception of protective factors and resilience. Future studies need to be carried out to determine which interventions can decrease the suicidal activity in the alcoholic patients. Additionally, several questions remain unanswered about the relationship between drug use disorders and suicide, indicating the need for future study.
Through comprehensive reporting, which in turn will provide useful guidelines for the clinical practice, our knowledge about alcohol use and other drugs in suicide deaths could be improved. Researchers and physicians have continued to establish alternative therapies that simultaneously target these conditions, with early signs of effectiveness, but there is still much to improve when it comes to alcohol consumption and addiction.
Conflict of interest: none declared
Financial support: none declared
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