Familial Transmission of Suicidal Behavior

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Adoption and twin studies show that familial transmission of suicidal behavior is partly attributable to genetic factors. Transmission of suicidal behavior is mediated by transmission of impulsive aggression or neuroticism and neurocognitive deficits. The most plausible explanations for nongenetic familial transmission are the intergenerational transmission of abuse and adverse familial environments. Bereavement and relationship disruption contribute to suicidal risk via the development of complicated grief, although long-term effects may be mediated by a complex chain of interrelated events. Imitation may contribute to suicidal risk, at least in attempted suicide. However, so-called family environmental factors often are related to risk factors that are heritable. Conversely, genetic factors exert their impact on depression and suicidal behavior via interaction with a stressful environment.

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Adoption Studies

Three adoption studies have been conducted, all using the same Danish adoption registry (Table 1). Kety and colleagues [2], in a study designed to examine the genetics of schizophrenia and mood disorders, found a nonsignificant trend toward higher concordance for suicide in biological, compared with adoptive relatives of adoptees who committed suicide. Subsequently, a second study compared the rates of suicide among the biological and adoptive relatives of adoptees who committed suicide versus

Twin Studies

In their review of twin case reports for suicide, Roy and Segal [5] found an increased concordance for suicide in monozygotic (MZ) versus dizygotic twins (DZ) (14.9% versus 0.7%), consistent with Tsuang's [6] original observations (Table 3, Table 4). Roy and colleagues [5], [7] found an even higher concordance rate for suicide attempt in the surviving monozygotic twin of the co-twin's suicide in MZ versus DZ twins (38% versus 0%), supporting the view that the clinical phenotype for concordance

Family Studies

Family studies compare the rate of suicide or suicidal behavior in the relatives of a proband with suicidality to the rate of suicide or suicidal behavior in the relatives of probands without suicidality. Studies have varied in outcome (family history of completed suicide, attempted suicide, or both), choice of proband (either completed or attempted suicide), choice of comparison group (community or psychiatric control), and method of assessment of family loading (record review, family history,

Studies of the Risk of Suicide in Probands with Completed Suicide

In studies that examined the familial rates of completed suicide in the relatives of probands who committed suicide, all show an elevated rate of completed suicide in the relatives of completers versus relatives of a comparison group, regardless of whether that comparison group consists of psychiatric, general medical, and community controls (Table 5). Also, these findings are consistent, regardless of whether the probands were drawn from large community pedigrees [14], diagnostically

Population Registry Studies

Four studies using Scandinavian registries report an increased risk of suicide conveyed to a first-degree relative, even after controlling for parental and personal history of inpatient psychiatric treatment (Table 6) [35], [37], [38], [41]. In one study, family history of suicide was associated with an increased rate of suicide even compared with those who have had a first-degree relative die from either accidents or homicides, supporting the view that the familial transmission of suicidal

Family Studies of Suicide Probands and Familial Rates of Suicidal Behavior

Four studies have examined rates of attempted and completed suicide in the families of suicide probands versus the relatives of community controls (Table 7) [23], [24], [28], [40]. Two studies focused on adolescents [23], [24], and two on adults [28], one of which focused exclusively on males [40]. All found an increased rate of suicidal behavior in the relatives of completers compared with relatives of community controls, even after controlling for differences in rates of psychiatric disorder

Family History of Suicidal Behavior in Suicide Attempting Probands

Table 8 lists 12 studies that have examined the rate of suicidal behavior in the families of suicide attempter probands, using a family history method. The findings are very consistent across studies, finding an increased rate of both completed and attempted suicide in the relatives of suicide attempters compared with the family members of controls. These findings are robust across a wide range of conditions: age of attempters (adolescents and adults), sampling frame (community samples,

Family Studies of Suicide-Attempting Probands

Three family studies of child or adolescent suicide-attempting probands have been conducted, finding an increased risk of suicide attempt in the relatives of suicide-attempting probands (Table 9) [21], [25], [26]. These studies also support a definition of the clinical phenotype that includes suicidal behavior, but does not include suicidal ideation, insofar as Pfeffer and colleagues [21] found that a family history of attempts was increased only in the relatives of proband attempters but not

High-Risk Studies

A variant of the family study, the high-risk study, has been used to prospectively examine the risks and processes associated with the familial transmission of suicidal behavior. In three studies that have taken this strategy, results are consistent—offspring of adult mood-disordered suicide attempters have a much higher risk of suicide attempt than offspring of mood-disordered probands who have never made a suicide attempt (Fig. 1). Greater familial loading for suicidal behavior is associated

Possible Mechanisms By Which Familial Transmission of Suicidal Behavior May Occur

Some possible intermediate phenotypes have emerged from family genetic studies. An intermediate phenotype according to Gottesman and Gould [53], must be related to the clinical phenotype, must be heritable, must predict the onset of the condition in offspring, and show evidence of mediation when controlling for the relationship between parent and offspring transmission of the overall clinical phenotype. The intermediate phenotype with the most convergent evidence is impulsive aggression, ie,

Parental Divorce and Separation

There is a large literature documenting a higher risk for suicidal behavior and suicide in children from non-intact families. However, divorce per se is unlikely to lead to suicidal behavior [41], [80], [81]. For example, marital disruption is more common in parents with psychiatric disorder. In studies that have examined the three-way relationships among divorce, parental and child psychiatric disorder, and child suicidal behavior, the relationship between divorce and child suicidal behavior

Summary

It is well recognized that suicidal behavior runs in families. Adoption and twin studies together make a compelling case that familial transmission of suicidal behavior is in part attributable to genetic factors. There is some evidence that the transmission of suicidal behavior is mediated by the transmission of impulsive aggression. Other, less thoroughly investigated possible mediators include neuroticism and neurocognitive deficits. However, given that at best, around 50% of the variance is

References (132)

  • A. Roy

    Characteristics of drug addicts who attempt suicide

    Psychiatry Res

    (2003)
  • R.D. Goodwin et al.

    Familial transmission of suicidal ideation and suicide attempts: evidence from a general population sample

    Psychiatry Res

    (2004)
  • D.A. Brent et al.

    Familial transmission of mood disorders: convergence and divergence with transmission of suicidal behavior

    J Am Acad Child Adolesc Psychiatry

    (2004)
  • E. Coccaro et al.

    Heritability of aggression and irritability: a twin study of the Buss-Durkee aggression scales in adult male subjects

    Biol Psychiatry

    (1997)
  • M. Chaffin et al.

    Onset of physical abuse and neglect: psychiatric, substance abuse and social risk factors from prospective community data

    Child Abuse Negl

    (1996)
  • D.A. Brent et al.

    Long-term impact of exposure to suicide: a three-year controlled follow-up

    J Am Acad Child Adolesc Psychiatry

    (1996)
  • M.T. Lynskey et al.

    Factors protecting against the development of adjustment difficulties in young adults exposed to childhood sexual abuse

    Child Abuse Negl

    (1997)
  • J. Cerel et al.

    Childhood bereavement: psychopathology in the 2 years postparental death

    J Am Acad Child Adolesc Psychiatry

    (2006)
  • J. Cerel et al.

    Suicide-bereaved children and adolescents: a controlled longitudinal examination

    J Am Acad Child Adolesc Psychiatry

    (1999)
  • M.S. Gould et al.

    Separation/divorce and child and adolescent completed suicide

    J Am Acad Child Adolesc Psychiatry

    (1998)
  • M.S. Gould et al.

    Youth suicide risk and preventative interventions: a review of the past 10 years

    J Am Acad Child Adolesc Psychiatry

    (2003)
  • G. Li

    The interaction effect of bereavement and sex on the risk of suicide in the elderly: an historical cohort study

    Soc Sci Med

    (1995)
  • J.L. Rowe et al.

    Social support and suicidal ideation in order adults using home healthcare services

    Am J Geriatr Psychiatry

    (2006)
  • D.A. Brent et al.

    Age and sex-related risk factors for adolescent suicide

    J Am Acad Child Adolesc Psychiatry

    (1999)
  • D.M. Fergusson et al.

    Childhood circumstances, adolescent adjustment, and suicide attempts in a New Zealand birth cohort

    J Am Acad Child Adolesc Psychiatry

    (1995)
  • D.A. Brent et al.

    Family genetic studies of suicide and suicidal behavior

    Am J Med Genet C Semin Med Genet

    (2005)
  • F. Schulsinger et al.

    A family study of suicide

  • P.H. Wender et al.

    Psychiatric disorders in the biological and adoptive families of adopted individuals with affective disorders

    Arch Gen Psychiatry

    (1986)
  • M.T. Tsuang

    Genetic factors in suicide

    Dis Nerv Syst

    (1977)
  • A. Roy et al.

    Attempted suicide among living co-twins of twin suicide victims

    Am J Psychiatry

    (1995)
  • D.J. Statham et al.

    Suicidal behaviour: an epidemiological and genetic study

    Psychol Med

    (1998)
  • Q. Fu et al.

    A twin study of genetic and environmental influences on suicidality in men

    Psychol Med

    (2002)
  • R. Plomin et al.

    Nature and nurture: genetic contributions to measures of the family environment

    Dev Psychol

    (1994)
  • B. Devlin et al.

    The heritability of IQ

    Nature

    (1997)
  • J.A. Egeland et al.

    Suicide and family loading for affective disorders

    J Am Med Assoc

    (1985)
  • B.D. Garfinkel et al.

    Suicide attempts in children and adolescents

    Am J Psychiatry

    (1982)
  • A. Roy

    Family history of suicide

    Arch Gen Psychiatry

    (1983)
  • M.T. Tsuang

    Risk of suicide in the relatives of schizophrenics, manics, depressives, and controls

    J Clin Psychiatry

    (1983)
  • P. Linkowski et al.

    Suicidal behaviour in major depressive illness

    Acta Psychiatr Scand

    (1985)
  • S.B. Sorenson et al.

    Transgenerational patterns of suicide attempt

    J Consult Clin Psychol

    (1991)
  • D.A. Brent et al.

    Suicidal behavior runs in families: a controlled family study of adolescent suicide victims

    Arch Gen Psychiatry

    (1996)
  • M.S. Gould et al.

    Psychosocial risk factors of child and adolescent completed suicide

    Arch Gen Psychiatry

    (1996)
  • B.A. Johnson et al.

    The familial aggregation of adolescent suicide attempts

    Acta Psychiatr Scand

    (1998)
  • T. Foster et al.

    Risk factors for suicide independent of DSM-III-R Axis I disorder: case control psychological autopsy study in Northern Ireland

    Br J Psychiatry

    (1999)
  • A.T. Cheng et al.

    Psychosocial and psychiatric risk factors for suicide: case-control psychological autopsy study

    Br J Psychiatry

    (2000)
  • J. Powell et al.

    Suicide in psychiatric hospital in-patients: risk factors and their predictive powers

    Br J Psychiatry

    (2000)
  • A. Roy

    Relation of family history of suicide to suicide attempts in alcoholics

    Am J Psychiatry

    (2000)
  • A. Roy

    Characteristics of cocaine-dependent patients who attempt suicide

    Am J Psychiatry

    (2001)
  • A. Roy

    Childhood trauma and neuroticism as an adult: possible implication for the development of the common psychiatric disorders and suicidal behaviour

    Psychol Med

    (2002)
  • A. Roy

    Characteristics of opiate dependent patients who attempt suicide

    J Clin Psychiatry

    (2002)
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    This work was supported by NIMH grants MH 43366, 55123, 6612, 56390, 66371, 62185, and 77930. The expert assistance of Beverly Sughrue in preparation of the manuscript is appreciated.

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