Familial Aggregation of Suicide Explained by Cluster B Traits: A Three-Group Family Study of Suicide Controlling for Major Depressive Disorder kongdi

 Objective  Method  Results  Discussion  Conclusions

Objective background  suicide aggregates in families  fivefold risk increase for suicidal behavior among relatives  extent of overlap between the liability to suicide and psychiatric disorders remains important  factors account for the familial transmission of suicidal behavior remain unclear

 a predisposition to be transmitted via intermediate phenotypes between genes and suicidal outcomes  cluster B personality disorders and associated traits may act as intermediate phenotypes of suicidal behavior  the study address these important issues by testing independence of liability to depression and suicide

 a family study of suicide by examining three proband groups: 1)probands who committed suicide in the context of major depressive disorder; 2)living depressed probands with no history of suicidal behavior; 3)psychiatrically normal community comparison probands;

Objective the comparison of rates of recurrence of suicidal behavior in relatives of three groups  tested the hypothesis that cluster B disorders and impulsive-aggressive behavior are intermediate phenotypes of suicide.

Method Proband Groups  Participants were 718 first-degree relatives from 120 families: 296 relatives of 51 depressed probands who committed suicide; 185 relatives of 34 nonsuicidal depressed probands; 237 relatives of 35 community comparison subjects.  Psychopathology, suicidal behavior, and behavioral measures were assessed via interviews.

Proband Comparability and Family Ascertainment  comparable age, sex,marital status, and income,but the first group had lower level of university education  relatives were directly and blindly assessed and scored for demographic characteristics, axis I and II disorders, suicidal behavior, and personality traits.

Assessments  SCID-I and SCID-II  Mental Health Clinical Research Center Suicide History Form  Brown-Goodwin History of Aggression  Barratt Impulsiveness Scale  Buss-Durkee Hostility Inventory  Temperament and Character Inventory Novelty seeking Harm avoidance Persistence

Statistical Analyses  chi-square tests  odds ratios and 95% confidence intervals  t tests or one-way analysis of variance  Tukey’s post hoc tests

Results  to current,Group 1were more likely to have met criteria for alcohol abuse and illicit substance abuse than other two groups.  Group 1 were also more likely than Group3, but not Group2, to have met criteria for lifetime alcohol abuse and illicit substance abuse.  comorbidity with cluster B personality pathology was more common among Group1

Suicidal Behavior Among Relatives Group1 had higher levels of suicidal behavior (10.8%) than Group2 (6.5%) anGroup3(3.4%).  Group1 and Group2 were more likely than Group3 to meet criteria for current and lifetime major depressive disorder.

 Group 1 had higher novelty seeking scores than Group2.  Group 1 had lower persistence scores than both Group2 and Group3.  Group2 had higher Buss-Durkee Hostility Inventory and harm avoidance scores than Group3.

Cluster B Traits as Intermediate Phenotypes of Suicide testing cluster B traits as intermediate phenotypes of suicide showed that Group 1 had elevated levels of cluster B traits.

Prevalence among probands.  Group1 exhibiting higher levels of cluster B traits than Group3.

Association with family predisposition to suicide familial predisposition to suicide was associated with increased levels of cluster B traits.

cluster Btraits are familial cluster B traits demonstrated familial aggregation and were associated with suicide attempts among relatives.

Mediating familial predisposition. cluster B traits mediated,the relationship between familial predisposition and suicide attempts among relatives.

Cluster B Traits and the Severity of Suicidal Behavior

Discussion  Suicidal Behavior  Liability to Psychiatric Illness  Impulsivity and Aggression

Strengths and Limitations  cross-generational  direct and blind assessment of relatives  cross-sectional, retrospective assessment of psychopathology and suicidal behavior  limited in our ability to examine suicide completion among relatives  future investigation in larger samples is warranted

Conclusions  Familial transmission of suicide and major depression, while partially overlapping, are distinct  Cluster Btraits and impulsive-aggressive behavior represent intermediate phenotypes of suicide.

Teacher Philips’ suggestion  This study can also been done in China.  They focus on the independent factor to explain why suicide aggregates in families.

Thank you !