Clinical and genetic risk factors for suicide under the influence of alcohol in a Polish sample

FOXN3 and GDNF Polymorphisms as Common Genetic Factors of Substance Use and Addictive Behaviors

Epidemiological and phenomenological studies suggest shared underpinnings between multiple addictive behaviors. The present genetic association study was conducted as part of the Psychological and Genetic Factors of Addictions study (n = 3003) and aimed to investigate genetic overlaps between different substance use, addictive, and other compulsive behaviors. Association analyses targeted 32 single-nucleotide polymorphisms, potentially addictive substances (alcohol, tobacco, cannabis, and other drugs), and potentially addictive or compulsive behaviors (internet use, gaming, social networking site use, gambling, exercise, hair-pulling, and eating). Analyses revealed 29 nominally significant associations, from which, nine survived an FDRbl correction. Four associations were observed between FOXN3 rs759364 and potentially addictive behaviors: rs759364 showed an association with the frequency of alcohol consumption and mean scores of scales assessing internet addiction, gaming disorder, and exercise addiction. Significant associations were found between GDNF rs1549250, rs2973033, CNR1 rs806380, DRD2/ANKK1 rs1800497 variants, and the “lifetime other drugs” variable. These suggested that genetic factors may contribute similarly to specific substance use and addictive behaviors. Specifically, FOXN3 rs759364 and GDNF rs1549250 and rs2973033 may constitute genetic risk factors for multiple addictive behaviors. Due to limitations (e.g., convenience sampling, lack of structured scales for substance use), further studies are needed. Functional correlates and mechanisms underlying these relationships should also be investigated.

The role of childhood adversities, FKBP5, BDNF, NRN1, and generalized self-efficacy in suicide attempts in alcohol-dependent patients

Background

Alcohol-dependent (AD) patients report higher number of adverse childhood experiences (ACEs), develop poor social skills, and have a higher rate of suicide attempts than the general population. We hypothesize that the association between ACEs and lifetime suicide attempts in AD patients is mediated by generalized self-efficacy and selected functional single nucleotide polymorphisms (SNPs) in genes involved in the stress response and neuroplasticity, including: FKBP5 rs1360780, BDNF rs6265, and NRN1 rs1475157.

Methods

176 AD patients and 127 healthy controls self-reported ACEs with the ACE Study questionnaire and three additional questions that inquired about ACE categories of acute stress; generalized self-efficacy—with the Generalized Self-Efficacy Scale. Genotyping for the three analysed SNPs was performed according to the manufacturer’s standard PCR protocol. Hypotheses were tested with bivariate analyses, multiple regression model, and mediation models.

Results

Higher levels of generalized self-efficacy were associated with a blunted effect of ACEs on the risk of suicide attempts. The prevalence of the three analyzed SNPs genotypes and alleles did not differ between AD patients with a positive vs. negative lifetime history of suicide attempt and was not associated with GSES scoring.

Conclusions

Generalized self-efficacy should be considered as a target for psychotherapeutic interventions aimed at reducing the risk of suicide attempts in AD patients who were exposed to childhood victimization. The negative results concerning the hypothesized role of the three analysed SNPs should be carefully interpreted due to the relatively small study sample, but represent a theoretical foundation for further research studies with larger study samples.

Electronic supplementary material

The online version of this article (10.1007/s43440-020-00080-8) contains supplementary material, which is available to authorized users.

Suicide Attempts: How Does the Acute Use of Alcohol Affect Suicide Intent?

BACKGROUND

Very few studies have specifically addressed the role of the acute use of alcohol (AUA) in suicide attempts.

OBJECTIVE

Our study compared the suicide intent scores of self-poisoning patients with and without AUA in order to examine the role of alcohol in attempted suicides.

METHODS

We recruited 516 patients admitted to the emergency department for self-poisoning. We screened blood alcohol concentrations (BACs) to determine whether these were positive or negative in the two groups. We collected data about covariates such as psychiatric disorders and sociodemographic and suicide characteristics. We then compared suicide intent between the groups, adjusted according to the covariates.

RESULTS

The patients with AUA had lower scores for suicide intent, but this factor only reduced the self-reporting score, with the scores for objective circumstances and risk similar between the groups. There was a correlation between BACs and self-reported suicide intentionality, but this was not significant.

CONCLUSION

Acute use of alcohol patients presented with lower suicide intent, as particularly explained by the self-report scores, but there were no differences between the groups in terms of risk and/or the objective circumstances. The role of alcohol in the self-reporting of suicide attempts must be addressed in future studies.

Predicting Planned Suicide Attempts With the Columbia-Suicide Severity Rating Scale: A Subanalysis of the 2013 Korea National Suicide Survey on Emergency Department Visitors

Identifying predictors of planned suicide attempts (PSA) is critical because these are associated with grave consequences. Using data of suicide attempters visiting emergency departments, we investigated whether the Columbia-Suicide Severity Rating Scale (C-SSRS) subscales, by retrospectively evaluating ideation before an attempt, could predict the occurrence of PSA versus unplanned suicide attempts using logistic regression analyses. The severity subscale was used as a continuous (model A) and a categorical (model B) variable. In model A, higher scores on each subscale were associated with increased risk of PSA. In model B, the highest score on the severity subscale and a higher intensity subscale score predicted PSA. The severity and intensity subscales had areas under receiver operating curves of 0.712 and 0.688 with optimum cutoff points of 4/5 and 15/16, respectively. In addition, being aged 30 to 49 and 50 to 69 years, being male, interpersonal stress, and depressive and adjustment disorders increased PSA risk. The C-SSRS subscales, along with sociodemographic and clinical risk factors, can predict PSA.

Psychoactive substances in natural and unnatural deaths in Norway and Sweden - a study on victims of suicide and accidents compared with natural deaths in psychiatric patients

BACKGROUND

The extent of post-mortem detection of specific psychoactive drugs may differ between countries, and may greatly influence the national death register's classification of manner and cause of death. The main objective of the present study was to analyse the magnitude and pattern of post-mortem detection of various psychoactive substances by the manner of death (suicide, accidental, undetermined and natural death with a psychiatric diagnosis) in Norway and Sweden.

METHODS

The Cause of Death Registers in Norway and Sweden provided data on 600 deaths in 2008 from each country, of which 200 were registered as suicides, 200 as accidents or undetermined manner of death and 200 as natural deaths in individuals with a diagnosis of mental disorder as the underlying cause of death. We examined death certificates and forensic reports including toxicological analyses.

RESULTS

The detection of psychoactive substances was commonly reported in suicides (66 and 74% in Norway and Sweden respectively), accidents (85 and 66%), undetermined manner of deaths (80% in the Swedish dataset) and in natural deaths with a psychiatric diagnosis (50 and 53%). Ethanol was the most commonly reported substance in the three manners of death, except from opioids being more common in accidental deaths in the Norwegian dataset. In cases of suicide by poisoning, benzodiazepines and z-drugs were the most common substances in both countries. Heroin or morphine was the most commonly reported substance in cases of accidental death by poisoning in the Norwegian dataset, while other opioids dominated the Swedish dataset. Anti-depressants were found in 22% of the suicide cases in the Norwegian dataset and in 29% of suicide cases in the Swedish dataset.

CONCLUSIONS

Psychoactive substances were detected in 66 and 74% of suicides and in 85 and 66% of accidental deaths in the Norwegian and Swedish datasets, respectively. Apart from a higher detection rate of heroin in deaths by accident in Norway than in Sweden, the pattern of detected psychoactive substances was similar in the two countries. Assessment of a suicidal motive may be hampered by the common use of psychoactive substances in suicide victims.

TPH2 polymorphisms across the spectrum of psychiatric morbidity: A systematic review and meta-analysis

Tryptophan hydroxylase 2 (TPH2) is the rate-limiting enzyme in brain serotonin synthesis. The TPH2 gene has frequently been investigated in relation to psychiatric morbidity. The aim of the present review is to integrate results from association studies between TPH2 single nucleotide polymorphisms (SNPs) and various psychiatric disorders, which we furthermore quantified with meta-analysis. We reviewed 166 studies investigating 69 TPH2 SNPs in a broad range of psychiatric disorders, including over 30,000 patients. According to our meta-analysis, TPH2 polymorphisms show strongest associations with mood disorders, suicide (attempt) and schizophrenia. Despite small effect sizes, we conclude that TPH2 SNPs in the coding and non-coding areas (rs4570625, rs11178997, rs11178998, rs10748185, rs1843809, rs4290270, rs17110747) are each associated with one or more psychopathological conditions. Our findings highlight the possible common serotonergic mechanisms of the investigated psychiatric disorders. Yet, the functional relevance of most TPH2 polymorphisms is unclear. Characterizing how exactly the different TPH2 variants influence the serotonergic neurotransmission is a next necessary step in understanding the psychiatric disorders where serotonin is implicated.

Co-ingested alcohol and the timing of deliberate self-poisonings

OBJECTIVE

Investigating diurnal variation in the timing of suicidal behaviours offers opportunity to better understand its various proximal risk factors. Acute use of alcohol is a potent proximal risk factor for suicidal behaviour, though the nature of this risk is poorly understood. The aim of this study was to compare the diurnal variation in time of poison ingestion between deliberate self-poisonings that involve alcohol versus those that do not.

METHODS

A retrospective analysis of consecutive presentations to a toxicology service following deliberate self-poisoning, 1996-2016. An independent samples Kolmogorov-Smirnov test was performed to test the null hypothesis that the diurnal distribution of poison ingestion time was equal across self-poisonings that did and did not involve alcohol co-ingestion. Presence of circadian rhythmicity was established using cosinor analysis.

RESULTS

A total of 11,088 deliberate self-poisoning records, for 7467 patients (60.8% females), were included in the analysis. In all, 31.3% of the total records involved alcohol co-ingestion. Distribution of exposure time was significantly different between deliberate self-poisonings that did and did not involve alcohol ( p < 0.001). The alcohol co-ingestion group showed a significantly greater prominent peak with poisoning occurring later in the evening (~20:00 hours) compared to poisonings that did not involve alcohol (~18:00 hours).

CONCLUSION

This study exposed the differential diurnal patterns in deliberate self-poisoning according to the presence of alcohol co-ingestion. This analysis adds to the accumulating evidence that suicidal behaviour that involves alcohol co-ingestion represents a distinct subtype, which may be driven by alcohol consumption patterns in society. This also means that this large proportion of deliberate self-poisonings may not otherwise have occurred if it were not for alcohol consumption, underscoring the importance of drug and alcohol services for alcohol-related self-harm.

Suicide behavior as a quantitative trait and its genetic background

INTRODUCTION

Studies have not given yet a clear answer what is the genetic background of suicidal predisposition. The associations between polymorphisms of the TPH1 and 5-HTTLPR genes and violent suicidal behavior was revealed with the least inconsistencies.

METHOD

We selected 10 "strong candidate genes" and 35 SNPs, SLC6A4 and ACP1 for replication study. We searched associations between precisely described suicidal phenotype in 825 affective patients and polymorphisms of selected neurobiological pathways genes as well as their interactions that constitute suicidal risk.

RESULTS

The results confirm the role of TPH1, TPH2, 5HT2A, CRHR1 and ACP1 variants in the risk of suicidal behavior.

LIMITATIONS

In our study we analyzed limited number of candidate genes and only one of them is linked to lithium mechanism of action. We had no data on pharmacological treatment of investigated patients and its relation to the time of suicide attempt.

CONCLUSION

Our results indicate that polymorphisms of various signaling pathways are involved in the pathogenesis of suicidal behavior. Non-genetic factors are also involved in the risk of suicidal attempts.

Role of Demographic and Personality Factors in Mediating Vulnerability to Suicide Attempts under Intoxication with Alcohol: A Record-based Exploratory Study

BACKGROUND

Identifying those who are likely to make suicide attempts under alcohol intoxication has important implications for management and prevention of further suicidal behavior.

AIMS

To identify the frequency of suicide attempts made under the influence of alcohol and the percentage of impulsive suicide attempts among them. We also aimed to identify predictors of attempted suicide under intoxication with alcohol.

SETTING AND DESIGN

Record-based study carried out at a tertiary care hospital.

MATERIALS AND METHODS

The clinical charts of consecutive suicide attempters (n = 147) who presented to the crisis intervention clinic from July 2013 to June 2014 were reviewed, and relevant data were extracted. The participants were divided into three groups - nonusers of alcohol (n = 85), alcohol users who did not attempt under intoxication (n = 31) and alcohol users who attempted under intoxication (n = 31). These groups were compared on various sociodemographic and clinical variables. Logistic regression was done to identify predictors of suicide attempt under intoxication.

STATISTICAL ANALYSIS USED

Chi-square (χ²) test, one-way ANOVA (F) test and backward stepwise logistic regression.

RESULTS

About 21.08% of all suicide attempts occurred under alcohol intoxication. Such subjects were more likely to be older (F = 12.428, P < 0.001), male (χ² = 87.367, P < 0.001), married (χ² = 6.787, P = 0.034), employed (χ² = 41.778, P < 0.001), and fewer years of formal schooling (F = 3.312, P = 0.039). Physical methods (hanging) were used more often in this group (χ² = 19.510, P = 0.012). In regression analysis, only marital status and living condition emerged as predictors of attempt under intoxication (odds ratios 4.52 [confidence interval (CI) 1.34-15.24, P = 0.015] and 5.67 [CI 1.17-27.39, P = 0.031] respectively).

CONCLUSION

Certain demographic features may help us in identifying those who are more likely to make attempts under intoxication. The role of personality factors as potential mediators of such behavior needs further exploration.

Inverse association between obesity predisposing FTO genotype and completed suicide

The A allele of rs9939609 in the FTO gene predisposes to increased body mass index (BMI) and obesity. Recently we showed an inverse association between the obesity related A allele of rs9939609 and alcohol dependence which was replicated by others. Since this finding raises a possibility that FTO may be associated with other psychiatric phenotypes, we aimed to examine association of rs9939609 with completed suicide. We genotyped rs9939609 in 912 suicide victims and 733 controls using TaqMan approach. We observed an inverse association between suicide and the rs9939609 A allele (OR = 0.80, P = 0.002, P_cor = 0.006) with genotype distribution suggesting a co-dominant effect. Given the link between alcoholism and suicide under influence of alcohol reported in Polish population, confounding by alcohol addiction was unlikely due to apparently similar effect size among cases who were under influence of ethanol at the time of death (OR = 0.76, P = 0.003, N = 361) and those who were not (OR = 0.80, P = 0.007, N = 469). The search for genotype-phenotype correlations did not show significant results. In conclusion, our study proves that there is an inverse association between rs9939609 polymorphism in FTO gene and completed suicide which is independent from association between FTO and alcohol addiction.

Alcohol and suicidal behavior: what is known and what can be done

Research on associations between substances of abuse and suicidal behaviors is a large, complex area. Herein, alcohol, the most commonly abused intoxicant worldwide, is examined with a focus on two topics: (1) acute use of alcohol (AUA) shortly prior to suicidal behavior; and (2) more chronic alcohol use disorder (AUD) and suicidal behavior. First, a brief summary of what is known about AUA, AUD, and suicidal behavior is provided. Next, we draw on preliminary evidence, practical considerations, and our own experience to offer recommendations for intervention research that may lower risk associated with AUA and AUD. The literature on AUD and suicidal behavior is more developed, thus we discuss separately research designed to: (1) prevent individuals with AUD with suicidal ideation from engaging in suicidal behavior; and (2) prevent individuals with AUD who have made a suicide attempt from reattempting. Our focus is on clinical intervention strategies for individuals at risk for suicidal behavior that use alcohol or have developed AUD. We also focus on applied research that may directly lead to practical prevention efforts. Although clinical interventions are important components of a comprehensive suicide prevention strategy, they should be complemented with primary prevention efforts.

Gene environment interaction studies in depression and suicidal behavior: An update

Increasing evidence supports the involvement of both heritable and environmental risk factors in major depression (MD) and suicidal behavior (SB). Studies investigating gene-environment interaction (G × E) may be useful for elucidating the role of biological mechanisms in the risk for mental disorders. In the present paper, we review the literature regarding the interaction between genes modulating brain functions and stressful life events in the etiology of MD and SB and discuss their potential added benefit compared to genetic studies only. Within the context of G × E investigation, thus far, only a few reliable results have been obtained, although some genes have consistently shown interactive effects with environmental risk in MD and, to a lesser extent, in SB. Further investigation is required to disentangle the direct and mediated effects that are common or specific to MD and SB. Since traditional G × E studies overall suffer from important methodological limitations, further effort is required to develop novel methodological strategies with an interdisciplinary approach.

Suicide attempts during heavy drinking episodes among individuals entering alcohol treatment in Warsaw, Poland

AIMS

Acute alcohol intoxication itself may act as a trigger for suicidal thoughts and attempts among individuals at risk and may influence the potential lethality of the suicide attempt. This study in alcohol-dependent patients compared the correlates of suicide attempts during a heavy drinking episode with those of suicide attempts during relative sobriety.

METHODS

In two outpatient and two residential alcohol treatment programs in Warsaw, Poland, 113 patients who reported a suicide attempt during their lifetime were interviewed. The analyses focused on the patients' most serious suicide attempts and on whether these occurred during a heavy drinking episode.

RESULTS

Over two-thirds of the patients reported that their most serious suicide attempt occurred during a period of heavy drinking. A multivariable logistic model indicated that the following factors significantly distinguished those patients whose most serious suicide attempt occurred during a heavy drinking episode: male gender, younger current age, greater severity of alcohol dependence and the attempt being unplanned.

CONCLUSION

Among the patients in treatment for alcohol dependence who made a suicide attempt, the most serious attempt was likely to have been unplanned and committed by men when it occurred during a heavy drinking episode.

Advances in tryptophan hydroxylase-2 gene expression regulation: new insights into serotonin-stress interaction and clinical implications

Serotonin (5-HT) modulates the stress response by interacting with the hormonal hypothalamic-pituitary-adrenal (HPA) axis and neuronal sympathetic nervous system (SNS). Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in 5-HT biosynthesis, and the recent identification of a second, neuron-specific TPH isoform (TPH2) opened up a new area of research. While TPH2 genetic variance has been linked to numerous behavioral traits and disorders, findings on TPH2 gene expression have not only reinforced, but also provided new insights into, the long-recognized but not yet fully understood 5-HT-stress interaction. In this review, we summarize advances in TPH2 expression regulation and its relevance to the stress response and clinical implications. Particularly, based on findings on rhesus monkey TPH2 genetics and other relevant literature, we propose that: (i) upon activation of adrenal cortisol secretion, the cortisol surge induces TPH2 expression and de novo 5-HT synthesis; (ii) the induced 5-HT in turn inhibits cortisol secretion by modulating the adrenal sensitivity to ACTH via the suprachiasmatic nuclei (SCN)-SNS-adrenal system, such that it contributes to the feedback inhibition of cortisol production; (iii) basal TPH2 expression or 5-HT synthesis, as well as early-life experience, influence basal cortisol primarily via the hormonal HPA axis; and (iv) 5'- and 3'-regulatory polymorphisms of TPH2 may differentially influence the stress response, presumably due to their differential roles in gene expression regulation. Our increasing knowledge of TPH2 expression regulation not only helps us better understand the 5-HT-stress interaction and the pathophysiology of neuropsychiatric disorders, but also provides new strategies for the treatment of stress-associated diseases.

Genetic and environmental contributions to self-reported thoughts of self-harm and suicide

Thoughts of self-harm and suicidal behavior are thought to be influenced by both genetics and environment. Molecular genetic studies are beginning to address the question of which genes may be involved and whether different genes may be expressed in men and women. We examined thoughts of self-harm and suicidal behavior in a large general population twin sample including male and female same- and opposite-sex twins. In this study, data on self-reported thoughts of self-harm and suicide were obtained from self-report questionnaires (Beck Depression Inventory and Youth or Adult Self Report forms) in 6,265 twin pairs (11,008 individuals) aged 11-90 (62% female) from the Netherlands Twin Registry. Liability threshold models were compared including sex and age (linear and quadratic) effects. Models were compared using measures of parsimony to calculate the simplest model to the data. A model with additive genetic and unique environmental contributions fitted the data for both males and females. There were no qualitative sex differences, but the relative contributions differed between men and women. Heritability was higher in women (0.74, 95% CI 0.65-0.81) than men (0.45, 95% CI 0.28-0.61). The remaining variance was accounted for by environmental influence unique to an individual. These results suggest contributions from additive genetic factors to self-reported thoughts of self-harm and suicide and support the continued study of both molecular genetic and individual-specific environmental risk factors.

Substance use and suicide

PURPOSE OF REVIEW

To address gaps identified in earlier reviews, namely, the comparative influence of substance use on attempted suicide and completed suicide; the proximal role of substance use as a trigger of suicidal behaviour; the association between substances and suicidal behaviour; suicide and substance use disorders in youth; and the influence of combinations of risk factors, including psychiatric morbidity, on suicide.

RECENT FINDINGS

The presence of an alcohol use disorder is confirmed as a distal risk factor for completed suicide, as well as attempted suicide. Alcohol use at the time of the suicide attempt is associated with low-risk methods. The use of other substances as a trigger of suicidal behaviour is highlighted in recent studies, but the circumstances leading to the suicidal act and the direct influence of substances in suicidal behaviour need to be explored further. Inhalant use and cocaine use are particularly associated with suicidal behaviour. Young people with multiple risk behaviours, such as substance use and risky sexual behaviours, are at high risk for suicidal behaviour. Psychiatric comorbidity with substance use escalates the risk for suicidal behaviour. Environmental interventions, such as reduction in the number of bars, may be helpful in reducing alcohol-related morbidity, including suicides.

SUMMARY

Prevention strategies for reducing suicidal behaviour among substance users need to be prioritized at the individual and the national level through effective design, policy and implementation.