Genetics of suicide: an overview

Development and Use of Suicide Registry for Recording Patient Profile with Self-harm Visiting Tertiary Hospital of Nepal: A Descriptive Cross-sectional Study

INTRODUCTION

Suicide is a major public health concern globally as well as in Nepal. It is important to have baseline data regarding suicide attempts to develop a prevention strategy. This study aims to describe the methodology used to develop a suicide registry and use it to collect data from patient visiting emergency or psychiatric outpatient department with suicide attempts in a tertiary care hospital.

METHODS

This is a descriptive cross-sectional study conducted retrospectively after obtaining ethical approval (Reference number: drs2005211371) from institutional review committee. Total sampling was done from the database covering the period from October 1, 2017, to September 30, 2023. The database was in the form of suicide registry that was developed after reviewing the existing data of primary health care centres, private hospitals, and tertiary care centers and a series of discussions among mental health experts. Data was entered in Microsoft Excel and analysis was done.

RESULTS

Among the 248 patients, there were 109 (43.95%) male and 139 (56.05%) female. There were 209 (84.27%) patients who attempted suicide inside home, poisoning was seen in 90 (36.29%) and 183 (73.79%) had impulsive intention. Out of total patients, 59 (23.79%) had prior communication and 84 (33.87%) had previous attempts, 109 (43.95%) patients had impulsive attempts as diagnosis and 75 (30.24%) had depression.

CONCLUSIONS

As per the suicide registry, most of the patients attempted suicide inside home and the most common method used was ingestion of poison.

Genome-wide association study meta-analysis of suicide death and suicidal behavior

Suicide is a worldwide health crisis. We aimed to identify genetic risk variants associated with suicide death and suicidal behavior. Meta-analysis for suicide death was performed using 3765 cases from Utah and matching 6572 controls of European ancestry. Meta-analysis for suicidal behavior using data across five cohorts (n = 8315 cases and 256,478 psychiatric or populational controls of European ancestry) was also performed. One locus in neuroligin 1 (NLGN1) passing the genome-wide significance threshold for suicide death was identified (top SNP rs73182688, with p = 5.48 × 10-8 before and p = 4.55 × 10-8 after mtCOJO analysis conditioning on MDD to remove genetic effects on suicide mediated by MDD). Conditioning on suicidal attempts did not significantly change the association strength (p = 6.02 × 10-8), suggesting suicide death specificity. NLGN1 encodes a member of a family of neuronal cell surface proteins. Members of this family act as splice site-specific ligands for beta-neurexins and may be involved in synaptogenesis. The NRXN-NLGN pathway was previously implicated in suicide, autism, and schizophrenia. We additionally identified ROBO2 and ZNF28 associations with suicidal behavior in the meta-analysis across five cohorts in gene-based association analysis using MAGMA. Lastly, we replicated two loci including variants near SOX5 and LOC101928519 associated with suicidal attempts identified in the ISGC and MVP meta-analysis using the independent FinnGen samples. Suicide death and suicidal behavior showed positive genetic correlations with depression, schizophrenia, pain, and suicidal attempt, and negative genetic correlation with educational attainment. These correlations remained significant after conditioning on depression, suggesting pleiotropic effects among these traits. Bidirectional generalized summary-data-based Mendelian randomization analysis suggests that genetic risk for the suicidal attempt and suicide death are both bi-directionally causal for MDD.

Genetic propensity for risky behavior and depression and risk of lifetime suicide attempt among urban African Americans in adolescence and young adulthood

Suicide attempts (SA) among African Americans have increased at a greater rate than any other racial/ethnic group. Research in European ancestry populations has indicated that SA are genetically influenced; however, less is known about the genetic contributors that underpin SA among African Americans. We examined whether genetic propensity for depression and risky behaviors (assessed via polygenic risk scores; PRS) independently and jointly are associated with SA among urban, African Americans and whether sex differences exist in these relations. Participants (N = 1,157, 45.0% male) were originally recruited as part of two first grade universal school-based prevention trials. Participants reported in adolescence and young adulthood on whether they ever attempted suicide in their life. Depression and risky behaviors PRS were created based on large-scale genome-wide association studies conducted by Howard et al. (2019) and Karlson Línner et al. (2019), respectively. There was a significant interaction between the risky behavior PRS and depression PRS such that the combination of high risky behavior polygenic risk and low/moderate polygenic risk for depression was associated with greater risk for lifetime SA among the whole sample and African American males specifically. In addition, the risky behavior PRS was significantly positively associated with lifetime SA among African American males. These findings provide preliminary evidence regarding the importance of examining risky behavior and depression polygenic risk in relation to SA among African Americans, though replication of our findings in other African American samples is needed.

The Sources of Parent-Child Transmission of Risk for Suicide Attempt and Deaths by Suicide in Swedish National Samples

OBJECTIVE

The authors aimed to clarify the sources of parent-child transmission for suicide attempt and death by suicide.

METHODS

Three sources of parent-child resemblance (genes plus rearing, genes only, and rearing only) were examined in parents and offspring from four family types from Swedish national samples: intact nuclear families, families with a not-lived-with biological father, families with a stepfather, and adoptees and their biological and adoptive parents. Parent-child resemblance was assessed primarily by tetrachoric correlation.

RESULTS

For suicide attempt to suicide attempt transmission, best-estimate tetrachoric correlations for genes plus rearing, genes only, and rearing only were 0.23 (95% CI=0.23, 0.24), 0.13 (95% CI=0.11, 0.15), and 0.14 (95% CI=0.11, 0.16), respectively. Suicide attempt was more strongly transmitted to male offspring compared with female offspring. Parental psychiatric disorders accounted for 40% of the genetic transmission but had no impact on rearing effects. For suicide death to suicide death transmission, best estimates of tetrachoric correlations for genes plus rearing, genes only, and rearing only were 0.16 (95% CI=0.15, 0.18), 0.07 (95% CI=0.02, 0.12), and -0.05 (95% CI=-0.17, 0.07), respectively. Although the suicide attempt-suicide death genetic correlation was high (0.84), the hypothesis that they reflect behaviors only differing in severity on the same continuum of genetic liability could be rejected.

CONCLUSIONS

The transmission of suicide attempt across generations is moderately strong and arises equally from genetic and rearing effects. Parental psychiatric illness explains almost half of the genetic transmission of suicide attempt but none of the rearing effect. Suicide death is modestly transmitted across generations, probably via genetic effects, although rearing may play a role. While suicide attempt and suicide death share a substantial proportion of their hereditary risk, they do not, from a genetic perspective, simply reflect milder and more severe forms of the same diathesis.

Genetic aetiology of self-harm ideation and behaviour

Family studies have identified a heritable component to self-harm that is partially independent from comorbid psychiatric disorders. However, the genetic aetiology of broad sense (non-suicidal and suicidal) self-harm has not been characterised on the molecular level. In addition, controversy exists about the degree to which suicidal and non-suicidal self-harm share a common genetic aetiology. In the present study, we conduct genome-wide association studies (GWAS) on lifetime self-harm ideation and self-harm behaviour (i.e. any lifetime self-harm act regardless of suicidal intent) using data from the UK Biobank (n > 156,000). We also perform genome wide gene-based tests and characterize the SNP heritability and genetic correlations between these traits. Finally, we test whether polygenic risk scores (PRS) for self-harm ideation and self-harm behaviour predict suicide attempt, suicide thoughts and non-suicidal self-harm (NSSH) in an independent target sample of 8,703 Australian adults. Our GWAS results identified one genome-wide significant locus associated with each of the two phenotypes. SNP heritability (hsnp2) estimates were ~10%, and both traits were highly genetically correlated (LDSC rg > 0.8). Gene-based tests identified seven genes associated with self-harm ideation and four with self-harm behaviour. Furthermore, in the target sample, PRS for self-harm ideation were significantly associated with suicide thoughts and NSSH, and PRS for self-harm behaviour predicted suicide thoughts and suicide attempt. Follow up regressions identified a shared genetic aetiology between NSSH and suicide thoughts, and between suicide thoughts and suicide attempt. Evidence for shared genetic aetiology between NSSH and suicide attempt was not statistically significant.

The intergenerational transmission of suicidal behavior: an offspring of siblings study

We examined the extent to which genetic factors shared across generations, measured covariates, and environmental factors associated with parental suicidal behavior (suicide attempt or suicide) account for the association between parental and offspring suicidal behavior. We used a Swedish cohort of 2,762,883 offspring born 1973-2001. We conducted two sets of analyses with offspring of half- and full-siblings: (1) quantitative behavior genetic models analyzing maternal suicidal behavior and (2) fixed-effects Cox proportional hazard models analyzing maternal and paternal suicidal behavior. The analyses also adjusted for numerous measured covariates (e.g., parental severe mental illness). Quantitative behavior genetic analyses found that 29.2% (95% confidence interval [CI], 5.29, 53.12%) of the intergenerational association was due to environmental factors associated with exposure to maternal suicidal behavior, with the remainder due to genetic factors. Statistical adjustment for parental behavioral health problems partially attenuated the environmental association; however, the results were no longer statistically significant. Cox hazard models similarly found that offspring were at a 2.74-fold increased risk [95% CI, 2.67, 2.83]) of suicidal behavior if their mothers attempted/died by suicide. After adjustment for familial factors and measured covariates, associations attenuated but remained elevated for offspring of discordant half-siblings (HR, 1.57 [95% CI, 1.45, 1.71]) and full-siblings (HR, 1.62 [95% CI, 1.57, 1.67]). Cox hazard models demonstrated a similar pattern between paternal and offspring suicidal behavior. This study found that the intergenerational transmission of suicidal behavior is largely due to shared genetic factors, as well as factors associated with parental behavioral health problems and environmental factors associated with parental suicidal behavior.

The association between general childhood psychopathology and adolescent suicide attempt and self-harm: A prospective, population-based twin study

Few quantitative behavior genetic studies have examined why psychopathology is associated with suicide attempt (SA) and self-harm (SH) in adolescence. The present study analyzed data from the Child and Adolescent Twin Study in Sweden to examine the extent to which genetic and environmental factors explain SA/SH and its association with psychopathology in childhood, an often-cited risk factor of subsequent SA/SH. When children were 9 or 12 years old (n = 30,444), parents completed the Autism-Tics, AD/HD and other Comorbidities Inventory (Larson et al., 2010) regarding their children's psychiatric problems as part of an ongoing, longitudinal study. At age 18 years (n = 10,269), adolescents completed self-report questionnaires, including SA/SH assessments. In a bifactor model of childhood psychopathology, a general factor of psychopathology was a statistically significant predictor of adolescent SA/SH at a higher magnitude (β, 0.25, 95% confidence interval [CI; 0.15, 0.34] for suicide attempt), as compared with specific factors of inattention, impulsivity, oppositional behavior, and anxiety/emotion symptoms. Quantitative genetic modeling indicated that the additive genetic influences on the general factor accounted for the association with each outcome (β, 0.24, 95% CI [0.13, 0.34] for suicide attempt). The results remained virtually identical when we fit a higher order factors model. Two additional outcomes demonstrated comparable results. The results extend current literature by revealing the shared genetic overlap between general psychopathology during childhood and adolescent SA/SH. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

An Investigation of Psychosis Subgroups With Prognostic Validation and Exploration of Genetic Underpinnings: The PsyCourse Study

IMPORTANCE

Identifying psychosis subgroups could improve clinical and research precision. Research has focused on symptom subgroups, but there is a need to consider a broader clinical spectrum, disentangle illness trajectories, and investigate genetic associations.

OBJECTIVE

To detect psychosis subgroups using data-driven methods and examine their illness courses over 1.5 years and polygenic scores for schizophrenia, bipolar disorder, major depression disorder, and educational achievement.

DESIGN, SETTING, AND PARTICIPANTS

This ongoing multisite, naturalistic, longitudinal (6-month intervals) cohort study began in January 2012 across 18 sites. Data from a referred sample of 1223 individuals (765 in the discovery sample and 458 in the validation sample) with DSM-IV diagnoses of schizophrenia, bipolar affective disorder (I/II), schizoaffective disorder, schizophreniform disorder, and brief psychotic disorder were collected from secondary and tertiary care sites. Discovery data were extracted in September 2016 and analyzed from November 2016 to January 2018, and prospective validation data were extracted in October 2018 and analyzed from January to May 2019.

MAIN OUTCOMES AND MEASURES

A clinical battery of 188 variables measuring demographic characteristics, clinical history, symptoms, functioning, and cognition was decomposed using nonnegative matrix factorization clustering. Subtype-specific illness courses were compared with mixed models and polygenic scores with analysis of covariance. Supervised learning was used to replicate results in validation data with the most reliably discriminative 45 variables.

RESULTS

Of the 765 individuals in the discovery sample, 341 (44.6%) were women, and the mean (SD) age was 42.7 (12.9) years. Five subgroups were found and labeled as affective psychosis (n = 252), suicidal psychosis (n = 44), depressive psychosis (n = 131), high-functioning psychosis (n = 252), and severe psychosis (n = 86). Illness courses with significant quadratic interaction terms were found for psychosis symptoms (R2 = 0.41; 95% CI, 0.38-0.44), depression symptoms (R2 = 0.28; 95% CI, 0.25-0.32), global functioning (R2 = 0.16; 95% CI, 0.14-0.20), and quality of life (R2 = 0.20; 95% CI, 0.17-0.23). The depressive and severe psychosis subgroups exhibited the lowest functioning and quadratic illness courses with partial recovery followed by reoccurrence of severe illness. Differences were found for educational attainment polygenic scores (mean [SD] partial η2 = 0.014 [0.003]) but not for diagnostic polygenic risk. Results were largely replicated in the validation cohort.

CONCLUSIONS AND RELEVANCE

Psychosis subgroups were detected with distinctive clinical signatures and illness courses and specificity for a nondiagnostic genetic marker. New data-driven clinical approaches are important for future psychosis taxonomies. The findings suggest a need to consider short-term to medium-term service provision to restore functioning in patients stratified into the depressive and severe psychosis subgroups.

Prospective Investigation of the Interaction Between Social Problems and Neuropsychological Characteristics on the Development of Suicide Ideation

OBJECTIVE

Negative social interactions are known to contribute to the development of suicide ideation. However, it is unclear how this risk factor interacts with other predisposing risk factors. The purpose of this study was to determine how social and neuropsychological factors interact as a prospective predictor of the emergence of suicide ideation in adolescents.

METHOD

Data were collected from adolescents (M age = 13.12, SD = 1.48) over 3 years as part of a larger study. Participants completed the MINI-Kid and Youth Self-Report, which were used to assess for suicidality. Negative social interactions were operationalized as the Social Problems scale of the YSR. Additionally, adolescents completed a neuropsychological battery at each wave of data collection.

RESULTS

Logistic moderation analyses demonstrated a significant interaction between task switching and endorsement of negative social interactions in the prediction of suicide ideation one year later, Wald χ² (1) = 4.94, OR = 0.90, p < .05. Distractibility was a significant predictor, Wald χ² (1) = 5.52, OR = 3.45, p < .05, but it did not demonstrate an interaction effect. Perseveration failed to reach statistical significance independently and in the interaction.

CONCLUSIONS

The results indicate that certain neuropsychological characteristics can aid in predicting which adolescents will develop suicide ideation in the presence of negative social interactions, which may have significant clinical implications.

Regulação molecular do ritmo circadiano e transtornos psiquiátricos: uma revisão sistemática

RESUMO Objetivo O artigo possui como objetivo investigar os genes relógio que estão mais associados com os transtornos psiquiátricos, as funções e localizações desses genes, assim como investigar o principal transtorno, método e modelo considerados nas análises. O trabalho busca resumir os achados e discutir o impacto dessas pesquisas no conhecimento científico. Métodos Esta revisão utilizou-se de uma metodologia sistemática (Prospero; ID 152031) e seguiu as diretrizes PRISMA. A busca dos estudos foi realizada nas bases de dados PubMed/MEDLINE e Scientific Eletronic Library Online e foram utilizados os termos do Medical Subject Headings Terms . Foram selecionados estudos quantitativos com resultados conclusivos referentes à associação de transtornos psiquiátricos com a regulação molecular do ritmo circadiano. As informações úteis foram extraídas e utilizadas para a elaboração de gráficos e tabelas. Resultados Foram incluídos 24 artigos em nosso estudo. Observou-se que o transtorno bipolar consistiu no transtorno psiquiátrico mais abordado (40% dos estudos); a nacionalidade polonesa dos participantes também se destacou em 39% dos trabalhos. Adicionalmente, o gene PER foi o mais estudado (25%) e o córtex cerebral foi a principal região em que os genes relógio avaliados se expressam (34%). A PCR comum mostrou ser o método mais utilizado (38%) e o metabolismo da serotonina mostrou ser a principal função desempenhada pelos produtos gênicos (16%). Conclusões Em conjunto, os resultados sugerem que o transtorno bipolar consiste no distúrbio psiquiátrico mais prevalente entre as pesquisas relacionadas aos genes circadianos, expressos principalmente no córtex cerebral de humanos, em especial o gene PER .

"Out, out, brief candle! Life's but a walking shadow": 5-HTTLPR Is Associated With Current Suicidal Ideation but Not With Previous Suicide Attempts and Interacts With Recent Relationship Problems

BACKGROUND

Suicide is an unresolved psychiatric and public health emergency, claiming 800,000 lives each year, however, its neurobiological etiology is still not understood. In spite of original reports concerning the involvement of 5-HTTLPR in interaction with recent stress in the appearance of suicidal ideation and attempts, replication studies have yielded contradictory results. In our study, we analyzed the association between 5-HTTLPR and lifetime suicide attempts, current suicidal ideation, hopelessness and thoughts of death as main effects, and in interaction with childhood adversities, recent stress, and different types of recent life events in a general population sample.

METHODS

Two thousand and three hundred fifty-eight unrelated European volunteers were genotyped for 5-HTTLPR, provided phenotypic data on previous suicide attempts, and current suicidal ideation, hopelessness and thoughts about death, and information on childhood adversities and recent life events. Logistic and linear regression models were run with age, gender, and population as covariates to test for the effect of 5-HTTLPR as a main effect and in interaction with childhood adversities and recent life events on previous suicide attempts and current suicidal ideation. Benjamini-Hochberg FDR Q values were calculated to correct for multiple testing.

RESULTS

5-HTTLPR had no significant effect on lifetime suicide attempts either as a main effect on in interaction with childhood adversities. 5-HTTLPR had a significant main effect on current suicidal ideation in the dominant model (Q=0.0344). 5-HTTLPR did not interact with childhood adversities or total number of recent life events on any phenotypes related to current suicidal risk, however, a significant interaction effect between 5-HTTLPR and current relationship problems emerged in the case of current suicidal ideation in the dominant model (Q=0.0218) and in the case of thoughts about death and dying in the dominant (Q=0.0094) and additive models (Q=0.0281).

CONCLUSION

While 5-HTTLPR did not influence previous suicide attempts or interacted with childhood adversities, it did influence current suicidal ideation with, in addition, an interaction with recent relationship problems supporting the involvement of 5-HTTLPR in suicide. Our findings that 5-HTTLPR impacts only certain types of suicide risk-related behaviors and that it interacts with only distinct types of recent stressors provides a possible explanation for previous conflicting findings.

Genetics of suicide attempts in individuals with and without mental disorders: a population-based genome-wide association study

Family studies have shown an aggregation of suicidal behavior in families. Yet, molecular studies are needed to identify loci accounting for genetic heritability. We conducted a genome-wide association study and estimated single nucleotide polymorphisms (SNP) heritability for a suicide attempt. In a case-cohort study, national data on all individuals born in Denmark after 1981 and diagnosed with severe mental disorders prior to 2013 (n = 57,377) and individuals from the general population (n = 30,000) were obtained. After quality control, the sample consisted of 6024 cases with an incidence of suicide attempt and 44,240 controls with no record of a suicide attempt. Suggestive associations between SNPs, rs6880062 (p-value: 5.4 × 10^-8) and rs6880461 (p-value: 9.5 × 10^-8), and suicide attempt were identified when adjusting for socio-demographics. Adjusting for mental disorders, three significant associations, all on chromosome 20, were identified: rs4809706 (p-value: 2.8 × 10^-8), rs4810824 (p-value: 3.5 × 10^-8), and rs6019297 (p-value: 4.7 × 10⁸). Sub-group analysis of cases with affective disorders revealed SNPs associated with suicide attempts when compared to the general population for gene PDE4B. All SNPs explained 4.6% [CI-95: 2.9-6.3%] of the variation in suicide attempt. Controlling for mental disorders reduced the heritability to 1.9% [CI-95: 0.3-3.5%]. Affective and autism spectrum disorders exhibited a SNP heritability of 5.6% [CI-95: 1.9-9.3%] and 9.6% [CI-95: 1.1-18.1%], respectively. Using the largest sample to date, we identified significant SNP associations with suicide attempts and support for a genetic transmission of suicide attempt, which might not solely be explained by mental disorders.

Risk factors for suicide in rural Italy: a case-control study

PURPOSE

Increased frequency of suicide in rural areas of Tuscany has been described since the 1970s. A case-control study was conducted in 2014 and 2015. The objective of this study was to identify major individual risk factors related to suicides in six rural districts of Tuscany.

METHODS

Cases were identified as all 128 suicides occurred in six rural districts between 2009 and 2013. Controls (three for each case) were matched for age, sex, and general practice. Information was collected from GPs using a structured questionnaire. Univariate and multivariate analyses were carried out to investigate the association between individual risk factors and suicide.

RESULTS

Informants for 91 cases of the 128 identified cases were successfully interviewed (response rate 71.1%). About 40.5-65.9% suicide cases and 11.4-20.0% of controls had some psychiatric pathology, accordingly to different definitions. Univariate conditional regression analysis showed that living in isolated houses (OR 2.48), living alone (OR 2.97), not being married (OR 2.63), low income (OR 2.73), psychiatric pathology (OR 9.70), psychotropic medication (OR 5.58), problems with relatives (OR 14.78), psychiatric family history (OR 5.67), and suicidal ideation (OR 15.61) were all risk factors. Practising religion (OR 0.27) was the only protective factor identified. Multivariate regression identified two independently and significantly associated variables namely, psychiatric pathology (OR 8.87) and living alone (OR 2.30).

CONCLUSIONS

Results of this study showed, similarly to recent research, that not all suicide events are the results of psychiatric pathology. Prevention strategies should, therefore, target both socio-economic and clinical risk factors.

Familial and social transmission of suicidal behavior in older adults

BACKGROUND

Both biological and social mechanisms have been implicated in the transmission of suicidal behavior in younger and middle-aged adults. Yet, while suicide rates rise with age, it is not clear whether such mechanisms operate in late life. Thus, we looked for evidence of social and familial suicidal transmission in elderly with late- vs. early-onset suicidal behavior by examining exposure to suicidal behavior within biological relatives and broader social networks.

METHOD

Participants were 356 adults, aged 50 or older (mean: 67), divided into five groups: early-onset suicide attempters (first lifetime attempt before age 60), late-onset attempters, suicide ideators (without attempt history), depressed non-suicidal controls, and non-psychiatric controls. History of suicidal behavior in one's biological relatives and friends/unrelated kin was assessed via clinical interview, and group differences were examined via generalized linear mixed-effects models.

RESULTS

There was a main effect of group (χ²₄ = 18.38, p < 0.001) such that familial or social exposure to suicidal behavior was more prevalent in early- than late-onset attempters. Late-onset attempters' exposure was similar to non-suicidal groups'. However, there was no significant group by relationship interaction, indicating that suicidal behavior was not significantly more prominent among the biological relatives of either attempter group.

LIMITATIONS

Participants' report of exposure is subject to awareness and recall biases.

CONCLUSION

Suicidal clustering in biological relatives and friends/unrelated kin is associated with early-, but not late-onset suicidal behavior in older adults. Suicidal transmission in older adults follows a pattern of familial and social clustering suggestive of social transmission.

Completed suicide in an autopsy-confirmed case of early onset Alzheimer's disease

We report a case of a 57-year-old male with clinically diagnosed and autopsy-confirmed early onset Alzheimer's disease who completed suicide by gunshot wound to the chest. This case has several unique aspects that have not been discussed in previous case reports of completed suicide in Alzheimer's disease. In particular, our patient's death was highly planned with successful compensation for his cognitive deficits. After all firearms had been removed from the home as a safety precaution, he obtained a new weapon, hid it and left himself cues to find and use it. The case is discussed in the context of literature differentiating the neural circuitry propagating impulsive versus planned suicidal acts.

The role of COMT gene Val108/158Met polymorphism in suicidal behavior: systematic review and updated meta-analysis

BACKGROUND

It is accepted that there is a genetic factor that influences the risk of suicidal behavior. The catechol-O-methyltransferase (COMT) gene, especially the Val108/158Met polymorphism, has been associated with suicide; however, no conclusive outcome has been attained. Therefore, the aim of the present study was to assess the role of COMT Val108/158Met in suicidal behavior throughout an updated meta-analysis.

METHODS

We performed an online search using PubMed and Web of Science (up to March 2017). Our systematic review included case-control studies of individuals who attempted suicide and completed suicide. We tested allelic, homozygous, heterozygous, dominant, and recessive inheritance models. The meta-analysis was performed in accordance with the statement of Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

RESULTS

The meta-analysis comprised 17 studies, which included 3,282 cases and 3,774 controls, and showed that when evaluating the overall population, the Val108/158Met polymorphism of COMT was not associated with suicidal behavior in any of the inheritance models; however, the subanalyses showed that this polymorphism exhibits a risk factor in males and a protective effect in females. Additionally, it conveyed a risk factor in Asian populations when using the allelic (OR 1.25; CI: 1.04-1.51) and recessive models (OR 1.32; CI: 1.03-1.68).

CONCLUSION

Our updated meta-analysis suggests a possible association between COMT Val108/158Met and suicidal behavior in Asian populations. However, in view of the small number of studies, these results should be considered exploratory. We recommend that more studies be performed with larger samples.

ABCA1 Polymorphism, a Genetic Risk Factor of Harm Avoidance

Abstract. Even though cholesterol homeostasis and self-harm behaviors have shown to be associated, gene polymorphisms of the cholesterol system have not been studied yet in the context of self-harm related personality traits. Here we present an association study between six ABCA1 polymorphisms and temperament scales measured by Cloninger’s Temperament and Character Inventory on 253 young adults. An association between ABCA1 rs4149264 and harm avoidance has been observed. This association remained significant after Bonferroni correction. Haplotype analysis confirmed an independent association between rs4149264 and harm avoidance. ABCA1, a cholesterol homeostasis gene, is a candidate gene for harm related personality traits.

Evidence for a Positive Ecological Correlation of Regional Intelligence and Suicide Mortality in the United States during the Early 20th Century

Several contemporary cross-national and intranational geographic studies have reported positive ecological (group-level) associations of intelligence and suicide mortality. These findings are consistent with facts from suicide research and with an evolutionary view of suicidal behavior. The present research extended these accounts cross-temporally. Analysis of E. L. Thorndike's state-level personal quality scores and standardized birth rates of eminent persons, taken as proxy variables for regional intelligence, along with historical state suicide rates (1913–1924 and 1928–1932) showed that intelligence and suicide mortality across the USA were already clearly positively related during the early 20th century, suggesting time stability of the effect. Within the USA, the effect is possibly due to state differences in the ethnic composition, which correspond to both suicide rates and intelligence proxies. It is argued that the most parsimonious interpretation of these ecological findings remains that they indeed reflect individual-level effects, that a positive link between intelligence and suicide is entirely compatible with positive overall links between intelligence and health and longevity, and that the ultimate explanative background for the positive link between intelligence and suicide may be provided through the framework of Rushton's differential K theory.

Belief and Disbelief in the Existence of Genetic Risk Factors for Suicide: Cross-Cultural Comparisons

There is evidence for widespread disbelief in the genetics of suicide, despite recent research progress in this area and convergent evidence supporting a role for genetic factors. This study analyzed the beliefs held in 8 samples (total N=1224) of various types (psychology, medical, and various undergraduates, psychology graduates, and the general population) from 6 countries located on 3 continents (Austria, Canada, Malaysia, Romania, United Kingdom, and the USA). Endorsement rates for the existence of genetic risk factors for suicide ranged from 26% and 30% (Austrian psychology undergraduates and general population) to around 50% (psychology undergraduates in the USA and United Kingdom). In the 8 samples, respondents' sex, age, religiosity, political orientation, and other demographic variables were, for the most part, unrelated, but overall knowledge about suicide throughout was related positively to endorsement rates. Consistent with previous research, across a considerable variety of sample types and cultural settings there was no evidence for a clear majority believing in genetic bases for suicide.

Correlates, Item-Sequence Invariance, and Test-Retest Reliability of the Beliefs in the Inheritance of Risk Factors for Suicide Scale (BIRFSS)

Genetic contributions to suicide are increasingly recognized. This study further validated the novel 22-item Beliefs in the Inheritance of Risk Factors for Suicide Scale (BIRFSS), which assesses individuals' beliefs about the genetics of suicide. Data from 155 mainly Austrian psychology undergraduates (42 men, 113 women) indicated adequate internal scale consistency and 2-mo. test-retest reliability. Scores were temporally stable and factor analysis of items yielded a dominant first factor. Scores were positively related to general beliefs about genetic determinism and to positive attitudes towards psychiatric genetic research (convergent validity), but unrelated to lay theories of suicide, locus of control, self-reported religiosity and political orientation, religious and spiritual beliefs, and social dominance orientation (discriminant validity). Effects of sex, age, and nationality (Austrian vs other) on scores were negligible. Item statistics corresponded strongly to those obtained from administering the item sequence in reverse order. Item statistics were strongly correlated with those observed in two previous validation studies, suggesting cross-sample robustness of the item-performance indicators of this measure. The scale shows potential for basic research and curriculum evaluation.

The Beliefs in the Inheritance of Risk Factors for Suicide Scale (Birfss): Further Results on Demographic Correlates, Dimensionality, Reliability, and Validity

Convergent lines of evidence from adoption, family, geographical, immigrant, molecular genetic, surname, and twin studies of suicide point to genetic contributions to risk factors for suicidal behavior. Related mental health literacy (knowledge and beliefs) of professionals and laypersons may, however, lag behind this research progress. The purpose of this study was to further validate the 22-item Beliefs in the Inheritance of Risk Factors for Suicide Scale (BIRFSS), a novel instrument for assessing individuals' beliefs in the genetics of suicide. Data from a general population sample of 159 Austrian adults showed adequate internal scale consistency. Due to deliberate content heterogeneity, the instrument has a subscale structure, but factor analysis of items extracted a dominant first factor. BIRFSS scores were positively related to overall and specific knowledge on suicide facts (convergent validity), whereas unrelated to the Big Five personality dimensions, locus of control, social desirability, and verbal intelligence (discriminant validity). Demographic correlates of BIRFSS scores included respondents' age and religiosity (both positive ones), but not respondents' sex, educational level, or political orientation.

Genetic Association Studies of Suicidal Behavior: A Review of the Past 10 Years, Progress, Limitations, and Future Directions

Suicidal behaviors (SBs), which range from suicidal ideation to suicide attempts and completed suicide, represent a fatal dimension of mental ill-health. The involvement of genetic risk factors in SB is supported by family, twin, and adoption studies. The aim of this paper is to review recent genetic association studies in SBs including (i) case-control studies, (ii) family-based association studies, and (iii) genome-wide association studies (GWAS). Various studies on genetic associations have tended to suggest that a number of genes [e.g., tryptophan hydroxylase, serotonin receptors and transporters, or brain-derived neurotrophic factors (BDNFs)] are linked to SBs, but these findings are not consistently supported by the results obtained. Although the candidate-gene approach is useful, it is hampered by the present state of knowledge concerning the pathophysiology of diseases. Interpretations of GWAS results are mostly hindered by a lack of annotation describing the functions of most variation throughout the genome. Association studies have addressed a wide range of single-nucleotide polymorphisms in numerous genes. We have included 104 such studies, of which 10 are family-based association studies and 11 are GWAS. Numerous meta-analyses of case-control studies have shown significant associations of SB with variants in the serotonin transporter gene (5-HTT or SLC6A4) and the tryptophan hydroxylase 1 gene (TPH1), but others report contradictory results. The gene encoding BDNF and its receptor (NTRK2) are also promising candidates. Only two of the GWAS showed any significant associations. Several pathways are mentioned in an attempt to understand the lack of reproducibility and the disappointing results. Consequently, we review and discuss here the following aspects: (i) sample characteristics and confounding factors; (ii) statistical limits; (iii) gene-gene interactions; (iv) gene, environment, and by time interactions; and (v) technological and theoretical limits.

Genetic Vulnerability as a Distal Risk Factor for Suicidal Behaviour: Historical Perspective and Current Knowledge

INTRODUCTION

Suicide is a multidimensional problem. Observations of family history of suicide suggest the existence of a genetic vulnerability to suicidal behaviour.

AIM

Starting with a historical perspective, the article reviews current knowledge of a genetic vulnerability to suicidal behaviour, distinct from the genetic vulnerability to psychiatric disorders, focused on clinical and population-based studies, and findings from recent molecular genetics association studies.

METHOD

The review includes peer-reviewed research articles and review papers from the professional literature in English language, retrieved from PubMed/Medline and PsycINFO.

RESULTS

The research literature confirms a existence of a genetic vulnerability to suicidal behaviour. Even though the results of individual studies are difficult to compare, genetic influences could explain up to half of the variance of the occurrence of suicide.

CONCLUSION

Genetic vulnerability could be a distal risk factor for suicide, which helps us to understand the occurrence of suicide among vulnerable people. Ethical implications of such vulnerability are highlighted.

The Influence of Parental Psychopathology on Offspring Suicidal Behavior across the Lifespan

Suicide tends to occur in families, and parental psychopathology has been linked to offspring suicidal behaviors. This study explores the influence of parental mental disorders across the lifespan. Data are from the Sao Paulo Megacity Mental Health Survey, a cross-sectional household study with a representative sample of the adult population living in the Sao Paulo Metropolitan Area, Brazil (N=2,942). Survival models examined bivariate and multivariate associations between a range of parental disorders and offspring suicidality. After controlling for comorbidity, number of mental disorders and offspring psychopathology, we found that parental psychopathology influences suicidal behaviors throughout most part of the life cycle, from childhood until young adult years. Generalized anxiety disorder (GAD) and antisocial personality were associated with offspring suicidal ideation (OR 1.8 and 1.9, respectively), panic and GAD predicted suicidal attempts (OR 2.3 and 2.7, respectively), and panic was related to the transition from ideation to attempts (OR 2.7). Although noticed in many different stages of the lifespan, this influence is most evident during adolescence. In this period, depression and antisocial personality increased the odds of suicidal ideation (OR 5.1 and 3.2, respectively), and depression, panic disorder, GAD and substance abuse predicted suicidal attempts (OR varying from 1.7 to 3.8). In short, parental disorders characterized by impulsive-aggression and anxiety-agitation were the main predictors of offspring suicidality across the lifespan. This clinically relevant intergenerational transmission of suicide risk was independent of offspring mental disorders, and this underscores the need for a family approach to psychopathology.

International Society for Bipolar Disorders Task Force on Suicide: meta-analyses and meta-regression of correlates of suicide attempts and suicide deaths in bipolar disorder

OBJECTIVES

Bipolar disorder is associated with a high risk of suicide attempts and suicide death. The main objective of the present study was to identify and quantify the demographic and clinical correlates of attempted and completed suicide in people with bipolar disorder.

METHODS

Within the framework of the International Society for Bipolar Disorders Task Force on Suicide, a systematic review of articles published since 1980, characterized by the key terms bipolar disorder and 'suicide attempts' or 'suicide', was conducted, and data extracted for analysis from all eligible articles. Demographic and clinical variables for which ≥ 3 studies with usable data were available were meta-analyzed using fixed or random-effects models for association with suicide attempts and suicide deaths. There was considerable heterogeneity in the methods employed by the included studies.

RESULTS

Variables significantly associated with suicide attempts were: female gender, younger age at illness onset, depressive polarity of first illness episode, depressive polarity of current or most recent episode, comorbid anxiety disorder, any comorbid substance use disorder, alcohol use disorder, any illicit substance use, comorbid cluster B/borderline personality disorder, and first-degree family history of suicide. Suicide deaths were significantly associated with male gender and first-degree family history of suicide.

CONCLUSIONS

This paper reports on the presence and magnitude of the correlates of suicide attempts and suicide deaths in bipolar disorder. These findings do not address causation, and the heterogeneity of data sources should limit the direct clinical ranking of correlates. Our results nonetheless support the notion of incorporating diagnosis-specific data in the development of models of understanding suicide in bipolar disorder.

Microglia of prefrontal white matter in suicide

Immune functions in the brain are associated with psychiatric illness and temporary alteration of mental state. Microglia, the principal brain immunologic cells, respond to changes in the internal brain milieu through a sequence of activated states, each with characteristic function and morphology. To assess a possible association of frontal white matter pathology with suicide, we stained autopsy brain tissue samples from 11 suicide and 25 nonsuicide subjects for ionized calcium-binding adapter molecule 1, cluster of differentiation 68, and myelin. Groups were matched by age, sex, and psychiatric diagnosis. We classified ionized calcium-binding adapter molecule 1-immunoreactive cells based on shape, immunoreactivity to cluster of differentiation 68, and association with blood vessels to obtain stereologic estimates of densities of resting microglia, activated phagocytes, and perivascular cells. We found no effect of psychiatric diagnosis but 2 statistically significant effects of suicide: 1) The dorsal-ventral difference in activated microglial density was reversed such that, with suicide, the density was greater in ventral prefrontal white matter than in dorsal prefrontal white matter, whereas in the absence of suicide, the opposite was true; and 2) with suicide, there was a greater density of ionized calcium-binding adapter molecule 1-immunoreactive cells within or in contact with blood vessel walls in dorsal prefrontal white matter. These observations could reflect a mechanism for the stress/diathesis (state/trait) model of suicide, whereby an acute stress activates a reactive process in the brain, either directly or by compromising the blood-brain barrier, and creates a suicidal state in an individual at risk. They also indicate the theoretical potential of imaging studies in living vulnerable individuals for the assessment of suicide risk. Further studies are needed to investigate specific phenotypes of perivascular cells and blood-brain barrier changes associated with suicide.

The molecular bases of the suicidal brain

Suicide ranks among the leading causes of death around the world and takes a heavy emotional and public health toll on most societies. Both distal and proximal factors contribute to suicidal behaviour. Distal factors - such as familial and genetic predisposition, as well as early-life adversity - increase the lifetime risk of suicide. They alter responses to stress and other processes through epigenetic modification of genes and associated changes in gene expression, and through the regulation of emotional and behavioural traits. Proximal factors are associated with the precipitation of a suicidal event and include alterations in key neurotransmitter systems, inflammatory changes and glial dysfunction in the brain. This Review explores the key molecular changes that are associated with suicidality and discusses some promising avenues for future research.

Association of TPH-1 and TPH-2 gene polymorphisms with suicidal behavior: a systematic review and meta-analysis

BACKGROUND

It is widely acknowledged that suicidal behavior (SB) has a genetic influence. As a consequence, molecular genetic studies have been mostly conducted on serotonergic genes. One of the most promising candidate genes of this system is tryptophan hydroxylase (TPH). Although there have been several positive studies associating TPH genes and SB, the evidence is not entirely consistent. Therefore, we performed a meta-analysis to gain a better understanding into this issue.

METHODS

The meta-analysis was conducted with 37 articles of genetic association studies of TPH-1 (A218C and A779C) and TPH2 (G-703 T, A-473 T and G19918A) genes. To analyze the association of these variants with SB we used the following models: allelic, additive, dominant and recessive. In addition, we performed a sub-group analysis by Caucasian and Asian populations using the same four models.

RESULTS

TPH-1 gene variants showed a positive significant association with SB, but only in the fixed effects models. With regard to TPH-2 gene variants we could not find an association with SB.

CONCLUSIONS

The study provides evidence that A218C/A779C TPH-1 variants may be a risk factor to manifest SB at the clinical level, which is in agreement with previously reported meta-analyses. With regard to G-703 T/A-473 T/G19918A TPH-2 variants, our up-to-date meta-analysis could not detect any significant association between those genetic variants and SB. However, these results should be interpreted with caution since further studies need to be undertaken using larger sample sizes in different ethnic populations to confirm our findings.

Attempted suicide in bipolar disorder: risk factors in a cohort of 6086 patients

OBJECTIVE

Bipolar disorder is associated with high risk of self-harm and suicide. We wanted to investigate risk factors for attempted suicide in bipolar patients.

METHOD

This was a cohort study of 6086 bipolar patients (60% women) registered in the Swedish National Quality Register for Bipolar Disorder 2004-2011 and followed-up annually 2005-2012. Logistic regression was used to calculate adjusted odds ratios for fatal or non-fatal attempted suicide during follow-up.

RESULTS

Recent affective episodes predicted attempted suicide during follow-up (men: odds ratio = 3.63, 95% CI = 1.76-7.51; women: odds ratio = 2.81, 95% CI = 1.78-4.44), as did previous suicide attempts (men: odds ratio = 3.93, 95% CI = 2.48-6.24; women: odds ratio = 4.24, 95% CI = 3.06-5.88) and recent psychiatric inpatient care (men: odds ratio = 3.57, 95% CI = 1.59-8,01; women: odds ratio = 2.68, 95% CI = 1.60-4.50). Further, those with many lifetime depressive episodes were more likely to attempt suicide. Comorbid substance use disorder was a predictor in men; many lifetime mixed episodes, early onset of mental disorder, personality disorder, and social problems related to the primary group were predictors in women.

CONCLUSION

The principal clinical implication of the present study is to pay attention to the risk of suicidal behaviour in bipolar patients with depressive features and more severe or unstable forms of the disorder.

Association between parental psychopathology and suicidal behavior among adult offspring: results from the cross-sectional South African Stress and Health survey

BACKGROUND

Prior studies have demonstrated a link between parental psychopathology and offspring suicidal behavior. However, it remains unclear what aspects of suicidal behavior among adult offspring are predicted by specific parental mental disorders, especially in Africa. This study set out to investigate the association between parental psychopathology and suicidal behavior among their adult offspring in a South African general population sample.

METHOD

Parental psychopathology and suicidal behavior in offspring were assessed using structured interviews among 4,315 respondents from across South Africa. The WHO CIDI was used to collect data on suicidal behavior, while the Family History Research Diagnostic Criteria Interview was used to assess prior parental psychopathology. Bivariate and multivariate survival models tested the associations between the type and number parental mental disorders (including suicide) and lifetime suicidal behavior in the offspring. Associations between a range of parental disorders and the onset of subsequent suicidal behavior (suicidal ideation, plans, and attempts) among adult offspring were tested.

RESULTS

The presence of parental psychopathology significantly increased the odds of suicidal behavior among their adult offspring. More specifically, parental panic disorder was associated with offspring suicidal ideation, while parental panic disorder, generalized anxiety disorder and suicide were significantly associated with offspring suicide attempts. Among those with suicidal ideation, none of the tested forms of parental psychopathology was associated with having suicide plans or attempts. There was a dose-response relationship between the number of parental disorders and odds of suicidal ideation.

CONCLUSIONS

Parental psychopathology increases the odds of suicidal behavior among their adult offspring in the South African context, replicating results found in other regions. Specific parental disorders predicted the onset and persistence of suicidal ideation or attempts in their offspring. Further research into these associations is recommended in order to determine the mechanisms through which parent psychopathology increases the odds of suicidal behavior among offspring.

Field procedures in the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS)

The Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS) is a multi-component epidemiological and neurobiological study of unprecedented size and complexity designed to generate actionable evidence-based recommendations to reduce US Army suicides and increase basic knowledge about determinants of suicidality by carrying out coordinated component studies. A number of major logistical challenges were faced in implementing these studies. The current report presents an overview of the approaches taken to meet these challenges, with a special focus on the field procedures used to implement the component studies. As detailed in the paper, these challenges were addressed at the onset of the initiative by establishing an Executive Committee, a Data Coordination Center (the Survey Research Center [SRC] at the University of Michigan), and study-specific design and analysis teams that worked with staff on instrumentation and field procedures. SRC staff, in turn, worked with the Office of the Deputy Under Secretary of the Army (ODUSA) and local Army Points of Contact (POCs) to address logistical issues and facilitate data collection. These structures, coupled with careful fieldworker training, supervision, and piloting, contributed to the major Army STARRS data collection efforts having higher response rates than previous large-scale studies of comparable military samples.

Genetic risk factors in two Utah pedigrees at high risk for suicide

We have used unique population-based data resources to identify 22 high-risk extended pedigrees that show clustering of suicide over twice that expected from demographically adjusted incidence rates. In this initial study of genetic risk factors, we focused on two high-risk pedigrees. In the first of these (pedigree 12), 10/19 (53%) of the related suicides were female, and the average age at death was 30.95. In the second (pedigree 5), 7/51 (14%) of the suicides were female and the average age at death was 36.90. Six decedents in pedigree 12 and nine in pedigree 5 were genotyped with the Illumina HumanExome BeadChip. Genotypes were analyzed using the Variant Annotation, Analysis, and Search program package that computes likelihoods of risk variants using the functional impact of the DNA variation, aggregative scoring of multiple variants across each gene and pedigree structure. We prioritized variants that were: (1) shared across pedigree members, (2) rare in other Utah suicides not related to these pedigrees, (3) < or = 5% in genotyping data from 398 other Utah population controls and (4) < or = 5% frequency in publicly available sequence data from 1358 controls and/or in dbSNP. Results included several membrane protein genes (ANO5, and TMEM141 for pedigree 12 and FAM38A and HRCT1 for pedigree 5). Other genes with known neuronal involvement and/or previous associations with psychiatric conditions were also identified, including NFKB1, CASP9, PLXNB1 and PDE11A in pedigree 12, and THOC1, and AUTS2 in pedigree 5. Although the study is limited to variants included on the HumanExome BeadChip, these findings warrant further exploration, and demonstrate the utility of this high-risk pedigree resource to identify potential genes or gene pathways for future development of targeted interventions.

Psychological morbidity among suicide-bereaved and non-bereaved parents: a nationwide population survey

OBJECTIVE

To determine how psychological premorbidity affects the risk of depression in parents who lost a child through suicide.

DESIGN

Population-based survey.

SETTING

Sweden, between 2009 and 2010.

PARTICIPANTS

All parents who lost a child, age 15-30, through suicide between 2004 and 2007 according to National population registries. Non-bereaved parents matched for age, sex, living area, marital status, number of children.

EXCLUSION CRITERIA

born outside a Nordic country, not Swedish speaking, contact details missing. Participants: 666 of 915 (73%) suicide-bereaved and 377 of 508 (74%) non-bereaved parents.

MAIN OUTCOME MEASURES

Depression measured by the nine-item depression scale of the Patient Health Questionnaire (PHQ-9) and study-specific questions to assess psychological premorbidity and experience of the child's presuicidal morbidity.

RESULTS

In all, 94 (14%) suicide-bereaved and 51 (14%) non-bereaved parents (relative risk 1.0; 95% CI 0.8 to 1.4) had received their first treatment for psychological problems or had been given a psychiatric diagnosis more than 10 years earlier. The prevalence of moderate-to-severe depression was 115 (18%) in suicide-bereaved versus 28 (7%) in non-bereaved parents (RR 2.3; 95% CI 1.6 to 3.5). For those without psychological premorbidity, the relative risk was 2.3 (95% CI 1.4 to 3.6). 339 (51%) suicide-bereaved parents expressed worry over the child's psychological health during the month preceding the suicide and 259 (39%) had anticipated the suicide.

CONCLUSIONS

In parents who lost a child through suicide in Sweden we did not find a higher prevalence of long-term psychological premorbidity than among parents who had not lost a child; the more than twofold risk of depression among the bereaved can probably be explained by the suicide and the stressful time preceding the suicide.

Suicidal Behavior and Neurological Illnesses

OBJECTIVE

Suicidal ideation and behavior have been associated with a variety of neurological illnesses. Studies are ongoing in combat veterans and other groups to examine possible mechanisms and pathways that account for such associations.

METHOD

This article provides a review of the literature on suicide ideation and suicidal behavior in patients with neurological illnesses including publications on veteran's health and military medicine. Studies of suicide attempts and deaths in people with neurological illnesses are also reviewed.

RESULTS

The studies summarized in this review indicate that there are important linkages between suicidal ideation and behavior and neurological conditions, including epilepsy, multiple sclerosis, and amyotrophic lateral sclerosis.

CONCLUSION

Additional studies are needed to further clarify why suicide ideation and suicidal behavior are associated with neurological diseases, in order to improve quality of life, alleviate patient distress, and prevent nonfatal and fatal suicide attempts in veteran and non-veteran populations.

Inevitable suicide: a new paradigm in psychiatry

The author suggests that a new paradigm may be needed which holds that some suicides may be inevitable. The goal of this paradigm would be to diminish the sense of failure and inadequacy felt by many psychiatrists who experience the suicide of a patient and to increase understanding of the unique biopsychosocial profile of those whose suicides appear to be inevitable. The author stresses that this proposed paradigm should not be misconstrued as therapeutic nihilism but rather should serve to stimulate efforts to treat this patient population more effectively. Risk factors that place individuals at high risk for suicide are reviewed, including presence of a mental illness, genetic predisposition, and factors such as a history of abuse, divorce, unemployment, male gender, recent discharge from a psychiatric hospital, prior suicide attempts, alcohol or other substance abuse, a history of panic attacks, and persistent suicidal thoughts, especially if coupled with a plan. The author notes that, in those suicides that appear to have been inevitable, risk factors are not only numerous but at the extreme end of profound pathology. The example of Ernest Hemingway is used to illustrate how such a combination of risk factors may have contributed to his eventual suicide. Psychiatrists, like other doctors, may have to acknowledge that some psychiatric disorders are associated with a high mortality rate as a natural outcome. This could lead to heightened vigilance, a more realistic view of what can and cannot be achieved with therapy, and efforts to improve the quality of life of patients at high risk for suicide with the goal of reducing this risk and prolonging their lives. (Journal of Psychiatric Practice 2012;18:221-224).

Suicidal Behavior in Surviving Co-Twins

Recent research has provided strong support for the existence of a familial risk for suicide, and efforts have been made to separate genetic from enviromental risk factors. Twin studies have played a major role in the identification of genetic factors, and the results indicate that the concordance rate for suicide is higher in identical than in fraternal twins (Baldessarini & Hennen, 2004). Moreover, Segal and Roy (1995) reported a significantly higher frequency of nonfatal suicidal attempts by monozygotic (MZ) than by dyzygotic (DZ) twins whose co-twins had committed suicide. However, doubts remain as to whether the increased risk of suicide in MZ twins is a response to the intense grief over the loss of a close relative, or whether a common genotype is associated with suicidal behavior. Sudden loss, which may carry a stigma in the case of a suicide, has been linked to increased persistent emotional stress and physiological changes (Epstein, 1993; Martin & Dean, 1993). A number of researchers have reported greater suicidal ideation among bereaved MZ twins as compared to DZ twins, suggesting that a loss due to suicide may increase the risk of suicidal behavior in the surviving co-twin (Segal & Bouchard, 1993; Segal & Roy, 1995; Segal et al., 1995). The aim of the present article is to address the issue of the intense grief experienced by twins after the co-twin suicide.

Variation in OPRM1 and risk of suicidal behavior in drug-dependent individuals

Completed suicide and nonfatal suicide-related outcomes (SROs), such as suicidal ideation and attempts, are heritable. A recent genetic association study in a sample of suicide victims reported a protective effect of the G allele of Asn40Asp (rs1799971) on risk for completed suicide. We examined the association of three OPRM1 single nucleotide polymorphisms (SNPs) (rs1799971, rs609148, and rs648893) with SRO in 426 European Americans, using GEE logistic regression analysis to examine the association of a lifetime history of SRO. There was no allelic association with the SRO phenotypes. A larger sample may be needed to identify risk variants that convey SRO risk. OPRM1 may not be important in the risk of SRO. 

Parental psychopathology and the risk of suicidal behavior in their offspring: results from the World Mental Health surveys

Previous research suggests that parental psychopathology predicts suicidal behavior among offspring; however, the more fine-grained associations between specific parental disorders and distinct stages of the pathway to suicide are not well understood. We set out to test the hypothesis that parental disorders associated with negative mood would predict offspring suicide ideation, whereas disorders characterized by impulsive aggression (for example, antisocial personality) and anxiety/agitation (for example, panic disorder) would predict which offspring act on their suicide ideation and make a suicide attempt. Data were collected during face-to-face interviews conducted on nationally representative samples (N=55 299; age 18+) from 21 countries around the world. We tested the associations between a range of parental disorders and the onset and persistence over time (that is, time since most recent episode controlling for age of onset and time since onset) of subsequent suicidal behavior (suicide ideation, plans and attempts) among offspring. Analyses tested bivariate and multivariate associations between each parental disorder and distinct forms of suicidal behavior. Results revealed that each parental disorder examined increased the risk of suicide ideation among offspring, parental generalized anxiety and depression emerged as the only predictors of the onset and persistence (respectively) of suicide plans among offspring with ideation, whereas parental antisocial personality and anxiety disorders emerged as the only predictors of the onset and persistence of suicide attempts among ideators. A dose-response relation between parental disorders and respondent risk of suicide ideation and attempt was also found. Parental death by suicide was a particularly strong predictor of persistence of suicide attempts among offspring. These associations remained significant after controlling for comorbidity of parental disorders and for the presence of mental disorders among offspring. These findings should inform future explorations of the mechanisms of intergenerational transmission of suicidal behavior.

Familial clustering of suicide risk: a total population study of 11.4 million individuals

BACKGROUND

Research suggests that suicidal behaviour is aggregated in families. However, due to methodological limitations, including small sample sizes, the strength and pattern of this aggregation remains uncertain.

METHOD

We examined the familial clustering of completed suicide in a Swedish total population sample. We linked the Cause of Death and Multi-Generation Registers and compared suicide rates among relatives of all 83 951 suicide decedents from 1952-2003 with those among relatives of population controls.

RESULTS

Patterns of familial aggregation of suicide among relatives to suicide decedents suggested genetic influences on suicide risk; the risk among full siblings (odds ratio 3.1, 95% confidence interval 2.8-3.5, 50% genetic similarity) was higher than that for maternal half-siblings (1.7, 1.1-2.7, 25% genetic similarity), despite similar environmental exposure. Further, monozygotic twins (100% genetic similarity) had a higher risk than dizygotic twins (50% genetic similarity) and cousins (12.5% genetic similarity) had higher suicide risk than controls. Shared (familial) environmental influences were also indicated; siblings to suicide decedents had a higher risk than offspring (both 50% genetically identical but siblings having a more shared environment, 3.1, 2.8-3.5 v. 2.0, 1.9-2.2), and maternal half-siblings had a higher risk than paternal half-siblings (both 50% genetically identical but the former with a more shared environment). Although comparisons of twins and half-siblings had overlapping confidence intervals, they were supported by sensitivity analyses, also including suicide attempts.

CONCLUSIONS

Familial clustering of suicide is primarily influenced by genetic and also shared environmental factors. The family history of suicide should be considered when assessing suicide risk in clinical settings or designing and administering preventive interventions.

No association between COMT val158met polymorphism and suicidal behavior: meta-analysis and new data

BACKGROUND

The polymorphism COMTval158met has been associated with suicidal behavior in case-control and meta-analysis studies, but results and conclusions remain controversial. The objective of this study was to examine the association between COMT val158met with suicidal behavior in a case-control study and to assess the combined evidence -this case-control study and available data from other related studies- we carried out a meta-analysis.

METHODS

We conducted a case-control study with 105 patients with suicide attempts and 236 controls. Subsequently, we performed a meta-analysis of published genetic association studies by searching through Medline, PubMed and Web of Science databases.

RESULTS

No significant differences were found in the distribution of alleles (χ2 = 0.33, 1 df, p = 0.56) or genotypes (χ2 = 2.36, 2 df, p = 0.26). The meta-analysis comprising 12 association studies (including the present one) showed that the risk COMTmet allele of COMTval158/met is not associated with suicidal behavior (OR: 1.09, 95% CI: 0.97-1.23), even in the absence of heterogeneity (OR: 1.09, 95% CI: 0.97-1.23).

CONCLUSION

Our results showed no association between COMTval158/met and suicidal behavior. However, more studies are necessary to determine conclusively an association between COMT and suicidal behavior.

An Evolutionary Hypothesis of Suicide: Why it Could be Biologically Adaptive and is so Prevalent in Certain Occupations

From an evolutionary perspective, suicide is a puzzle, because it has serious adverse effects, yet is remarkably common and heritable. An hypothesis is proposed to explain this puzzle, by explaining how suicide could be adaptive through reducing risk that individuals will transmit infections to kin. Empirical evidence supports four predictions from the hypothesis. There are well-established mechanisms by which infections and immune factors increase risk for mental disorders that contribute to suicide. Suicide is more prevalent in occupations with greater exposure to infection and immune-compromising factors and at higher latitudes, where key environmental factors increase vulnerability to infection. In several other highly social species, suicide-like behaviors have evolved to reduce transmission of infections. If the hypothesis is correct, detection and treatment of underlying infections and immune dysfunction should help predict and prevent suicidal behavior, while also combating spread of infectious diseases.

Maternal smoking during pregnancy and risks of suicidal acts in young offspring

Obstetric and neonatal complications have been associated with completed and attempted suicide (suicidal acts) in young offspring. Maternal smoking is one of the most important risk factors for obstetric complications, but the association between prenatal smoking exposure and offspring risk of suicidal acts is unknown. We performed a population-based study of 1,449,333 single births born in Sweden between 1983 and 1996, derived from linked registry data. Maternal smoking and risks of suicidal acts in offspring were estimated using hazard ratios, derived from proportional-hazard models, controlling for potential confounding of parental socio-demographic factors and psychiatric care in first degree relatives. To control for unmeasured familial confounding, a matched case-control analysis of suicidal acts was performed within sibling pairs discordant for prenatal smoking exposure. In the cohort analysis, the adjusted hazard ratio for completed suicide among offspring to women smoking 1-9 cigarettes and at least 10 cigarettes per day were 1.67, 95% confidence interval (CI), 1.29-2.16, and 1.54, 95% CI, 1.12-2.10. For suicidal acts, corresponding hazard ratios were 1.28, 95% CI 1.21-1.35 and 1.48, 95% CI 1.39-1.57, respectively. However, in sibling pairs discordant for suicidal acts and prenatal smoking exposure, we found no evidence that prenatal smoking exposure increased the risk of suicidal acts. We conclude that the association between prenatal smoking exposure and offspring risk of suicidal acts is probably confounded by unmeasured familial factors.

An overview of mood disorders in the DSM-5

The process of revising the DSM, which is based on new findings in the literature and experience with the current classification, is initiated every 12-18 years. The process for the revision of DSM-IV to the DSM-5 began in 2006-after a series of meeting proceedings and monographs were published during the previous 3 years-with the appointment of diagnostic group chairs by Director Dr. David Kupfer and Vice Director Dr. Darrel Regier. Members were recruited for workgroups to review the existing DSM-IV, to decide what worked well and which areas needed change, to review the available literature and data, and to propose changes based on an appropriate level of evidence in the literature proportional to the significance of the change. At the halfway point in this process, the Mood Disorders Workgroup has made tentative recommendations to be tested in field trials. These recommendations and some of the basis for them are discussed in this review. Final decisions await the data from field trials, possible revisions by the workgroups, and action by the task force. This article describes some of the recommendations made by the Mood Disorders Workgroup at this point in the process.

Surrogate endpoints in suicide research

Surrogate endpoints frequently substitute for rare outcomes in research. The ability to learn about completed suicides by investigating more readily available and proximate outcomes, such as suicide attempts, has obvious appeal. However, concerns with surrogates from the statistical science perspective exist, and mounting evidence from psychometric, neurochemical, genetic, and neuroimaging studies suggests that surrogates may be particularly problematic in suicide research. The need for greater phenotypic refinement of suicide-related behaviors, development of and adherence to a shared suicide nomenclature, and conservative interpretation of investigational results that are limited to the precise population and suicide-related behavior under examination are discussed.

Association of HPA axis genes with suicidal behaviour in schizophrenia

Family, adoption and twin studies show that genetics influences suicidal behaviour, but do not indicate specific susceptibility variants. Stress response is thought to be mediated by the corticotrophin-releasing hormone (CRH), which is known to be a regulator of the hypothalamic-pituitary-adrenal pathway (HPA). Alterations in HPA system have been related to impulsivity, aggression and suicidal behaviour, common feature in schizophrenia. CRH is the hypothalamic factor that stimulates the pituitary gland. To search for markers conferring genetic susceptibility to suicide, we typed six HPA axis genes (CRH, CRHR1, CRHR2, CRHBP, MC2R, NC3R1) in a cohort of 231 subjects with schizophrenia in which 81 attempted suicide. The genotype analyses yielded significant association between CRH binding protein (CRHBP) and suicide attempt (P = 0.035). The genotype analysis for quantitative measures of suicidal behaviour showed no association. The interaction analysis showed a significant interaction between CRH receptor type 1 (CRHR1) and CRH binding protein (CRHBP) in influencing suicide attempt and the severity of suicidal behaviour. Current results show that genetic variation in HPA axis genes could be associated with suicidal behaviour in schizophrenia. This is to our knowledge the first study on suicidal behaviour investigating the interaction among the HPA axis genes.

Suicidal behaviors in surviving monozygotic and dizygotic co-twins: is the nature of the co-twin's cause of death a factor?

Genetically informative samples can address hereditary and experiential influences on suicide-related behaviors. The frequency of suicide-related behaviors was compared in twins from two survivor groups: (1) those whose co-twins' deaths were suicides (monozygotic [MZ]: n = 47; dizygotic [DZ]: n = 31), and (2) those whose co-twins' deaths were nonsuicides (MZ: n = 347; DZ: n = 170). The frequency of suicide attempts among suicide survivors was significantly higher in MZ than DZ twins, while the frequency of suicide attempts among nonsuicide twin survivors did not differ between MZ and DZ twins. Twin concordance for suicide attempts more likely reflects a genetic predisposition than a behavioral reaction to the loss.

The beliefs in the inheritance of risk factors for suicide scale (BIRFSS): cross-cultural validation in Estonia, Malaysia, Romania, the United Kingdom, and the United States

The genetics of suicide is increasingly recognized and relevant for mental health literacy, but actual beliefs may lag behind current knowledge. We examined such beliefs in student samples (total N = 686) from Estonia, Malaysia, Romania, the United Kingdom, and the United States with the Beliefs in the Inheritance of Risk Factors for Suicide Scale. Cultural effects were small, those of key demographics nil. Several facets of construct validity were demonstrated. Marked differences in perceived plausibility of evidence about the genetics of suicide according to research design, observed in all samples, may be of general interest for investigating lay theories of abnormal behavior and communicating behavioral and psychiatric genetic research findings.

Suicide and suicidal behavior

Suicidal behavior is a leading cause of injury and death worldwide. Information about the epidemiology of such behavior is important for policy-making and prevention. The authors reviewed government data on suicide and suicidal behavior and conducted a systematic review of studies on the epidemiology of suicide published from 1997 to 2007. The authors' aims were to examine the prevalence of, trends in, and risk and protective factors for suicidal behavior in the United States and cross-nationally. The data revealed significant cross-national variability in the prevalence of suicidal behavior but consistency in age of onset, transition probabilities, and key risk factors. Suicide is more prevalent among men, whereas nonfatal suicidal behaviors are more prevalent among women and persons who are young, are unmarried, or have a psychiatric disorder. Despite an increase in the treatment of suicidal persons over the past decade, incidence rates of suicidal behavior have remained largely unchanged. Most epidemiologic research on suicidal behavior has focused on patterns and correlates of prevalence. The next generation of studies must examine synergistic effects among modifiable risk and protective factors. New studies must incorporate recent advances in survey methods and clinical assessment. Results should be used in ongoing efforts to decrease the significant loss of life caused by suicidal behavior.

Beliefs about the genetics of suicide in Canadian students: cross-language validation of the Beliefs in the Inheritance of Risk Factors for Suicide Scale (BIRFSS)

AIM

The genetics underlying suicidal behavior is becoming increasingly recognized and investigated. Convergent evidence towards this end has emerged from numerous research strategies (adoption, family, genome-scan, geographic, immigrant, molecular genetic, surname, and twin studies of suicide). The topic-related mental-health literacy (i.e. knowledge and beliefs) of professionals and laypersons, however, may lag behind this research progress, and data on this question are scant. The aim of the present study was therefore to further validate, in a cross-language setting, the novel 22-item Beliefs in the Inheritance of Risk Factors for Suicide Scale (BIRFSS), originally developed in German, which assesses beliefs about the genetics of suicide.

METHODS

Data were collected from a mixed student sample from Canada (n = 288; 70.5% females, 58.0% studying psychology as a major or minor).

RESULTS

Factor analysis of BIRFSS items yielded a dominant first factor. Internal scale consistency was, however, only middling (lower than previously observed in Austrian samples). Although the structure of beliefs about the genetics of suicide seems to be complex, the Canadian sample's item-performance indicators corresponded strongly to those obtained in Austrian samples, thus indicating cross-sample and cross-language robustness of item statistics.

CONCLUSION

For the Canadian sample, BIRFSS scores were positively related to overall and specific knowledge about suicide and general beliefs about genetic determinism (convergent validity), whereas they were not (or only trivially) related to the Big Five personality dimensions, lay theories of suicide, locus of control, social desirability, religiosity, and political orientation (discriminant validity), and to several key demographic variables. Supplemental findings, study limitations, application possibilities, user recommendations, and avenues for further inquiry are discussed.

A further test of the Finno-Ugrian Suicide Hypothesis: correspondence of county suicide rates in Romania and population proportion of ethnic Hungarians

Across the 42 counties of Romania, the total suicide rate and the population percentage of ethnic Hungarians were strongly positively interrelated (79% attributable variance). Counties with the strongest Hungarian minority had suicide rates converging to (or exceeding) the suicide rate for Hungary, which rate is high. Of a set of about 20 vital statistics and socioeconomic indicators, only life expectancy predicted a significant increment of further variance in the suicide rates. However, this effect was small, adding merely 3% further variance explained to 79% already accounted for. Overall, the findings are supportive of the Finno-Ugrian Suicide Hypothesis, i.e., the notion that geographic patterns of suicide prevalence may be partially due to genetic differences between populations. Supplemental analyses of a questionnaire item which specifically queried this study's main finding indicated widespread disbelief of this fact of suicide prevalence across a variety of samples, including two samples from Romania.