Suicidal Behavior in Surviving Co-Twins

Risk of psychiatric disorders among the surviving twins after a co-twin loss

Losing a co-twin by death is a severely stressful event yet with unknown impact on the surviving twin's risk of psychiatric disorders. We identified all Swedish-born twins who lost a co-twin by death between 1973 and 2013 (n = 4,528), their 4939 non-twin full siblings, together with 22,640 age- and sex-matched non-bereaved twins. Compared to the non-bereaved twins, exposed twins were at increased risk of receiving a first diagnosis of psychiatric disorders (hazard ratio = 1.65, 95% confidence interval1.48-1.83), particularly during the first month after loss. Similarly, compared to non-twin full siblings, the relative risks were significantly increased after loss of monozygotic co-twin (2.45-fold), and loss of a dizygotic co-twin (1.29-fold), with higher HR observed with greater age gaps between twins and non-twin siblings. As dizygotic twins share equal genetic relatedness to the deceased twin as their full siblings, this pattern suggests that beyond the contribution of genetic factors, shared early life experiences and attachment contribute to the risk of psychiatric disorders among surviving twins after co-twin loss.

Bereavement after the suicide of a significant other

CONTEXT

It is estimated that approximately one in four people know someone who has taken their own life and that one suicide death leaves six or more suicide survivors.

AIMS

The aim of this paper was to review the literature regarding the association between suicide and bereavement, focusing also on the supportive and therapeutic resources available for survivors.

MATERIALS AND METHODS

Careful MedLine and PsycINFO searches for the period 1980-2013.

RESULTS

The review of the literature indicates that emotional turmoil in suicide survivors may last a long time and, in some cases, may end with their own suicide.

CONCLUSION

Future research should evaluate the efficacy of professional treatments and of support groups targeting suicide survivors.

PRACTICE IMPLICATIONS

It is crucial to understand the bereavement process after the suicide of a significant other in order to provide proper care, reduce stigma, and improve the outcomes of related psychiatric conditions.

The possible contributory role of the S allele of 5-HTTLPR in the emergence of suicidality

Suicide is a complex and challenging human phenomenon, and, although knowledge is expanding concerning its risk factors, its background is still not fully understood. There is currently an increasing interest in genetic factors associated with suicide, since these may lead to the emergence of personality traits and temperaments that may be long-term predictors of suicidal behaviour. One of the most likely genetic candidates in the background of suicide is the 5-HTTLPR polymorphism of the serotonin transporter gene. This review focused on papers published on the association of the 5-HTTLPR polymorphism of the serotonin transporter gene and suicidal behaviour as well as research on possible endophenotypes related to suicide. Although there are contradictory results, several studies and meta-analyses support the idea that the S allele plays a role in the background of violent suicide. However, in order to be able to delineate the genetic background of suicide, different types of suicidal behaviour should be distinguished, since studies indicate that these may have different genetic factors. Also, personality traits and temperaments should be identified that may play a modulating role between genetic factors and suicidal behaviour. So far, neuroticism, affective temperaments, and impulsive aggression have been found to be associated with both the S allele and suicidal behaviour. This study aimed to integrate findings concerning possible endophenotypes modulating between genetic factors and manifested suicidal behaviour.

Genetics of suicide: a systematic review of twin studies

OBJECTIVES

Convergent evidence from a multitude of research designs (adoption, family, genomescan, geographical, immigrant, molecular genetic, surname, and twin studies of suicide) suggests genetic contributions to suicide risk. The present account provides a comprehensive and up-to-date review of the twin studies on this topic.

METHODS

A total of 32 studies (19 case reports, 5 twin register-based studies, 4 population-based epidemiological studies, 4 studies of surviving co-twins) located through extensive literature search strategies are summarized and discussed here. This literature corpus was published between 1812 and 2006 in six languages and reports data from 13 countries.

RESULTS

A meta-analysis of all register-based studies and all case reports aggregated shows that concordance for completed suicide is significantly more frequent among monozygotic than dizygotic twin pairs. The results of co-twin studies rule out exclusively psychosocially based explanations of this pattern. Population-based epidemiological studies demonstrate a significant contribution of additive genetic factors (heritability estimates: 30-55%) to the broader phenotype of suicidal behavior (suicide thoughts, plans and attempts) that largely overlaps for different types of suicidal behavior and is largely independent of the inheritance of psychiatric disorders. Nonshared environmental effects (i.e. personal experiences) also contribute substantially to the risk of suicidal behavior, whereas effects of shared (family) environment do not.

CONCLUSIONS

The totality of evidence from twin studies of suicide strongly suggests genetic contributions to liability for suicidal behavior. To further research progress in this area, an extensive discussion of design limitations, shortcomings of the literature and further points is provided, including sources of bias, gaps in the literature, errors in previous reviews, age and sex effects and twin-singleton differences in suicide risk, and notes from a history-of-science view.

Consistency in suicide rates in twenty-two developed countries by gender over time 1874--78, 1974--76, and 1998--2000

To determine whether the relative levels of suicide rates among the 22 developed countries were consistent over time 1974--76 v 2000--02 and to compare Durkheim's 11 European countries 1874--78 with their modern counterparts, including the 1984--86 period associated with the European recession. Data from the WHO of All Age "General Population Suicide Rates" (GPSR) by sex were calculated to obtain 3-year averages for the end-points. To determine the consistency of the levels of suicides a series of Spearman Rank Order correlations are calculated for each period. Highly significant correlations are found for men, women and total suicide rates between 1974--76 and 1998--2000, and for the Durkheim countries for the three review periods, indicating despite within-national variations over time, the relative rates between countries was consistent. This consistency suggests a certain national "suicide tradition" based on a complex interaction between cultural, sociological, recording/administrative, and genetic factors.