Impulsive-aggressive behaviours and completed suicide across the life cycle: a predisposition for younger age of suicide.
BACKGROUND
It is unclear whether the association between impulsive-aggressive behaviours and suicide exists across different ages.


METHODS
Via psychological autopsy, we examined a total of 645 subjects aged 11-87 years who died by suicide. Proxy-based interviews were conducted using the SCID-I & SCID-II or K-SADS interviews and a series of behavioural and personality-trait assessments. Secondarily, 246 living controls were similarly assessed.


RESULTS
Higher levels of impulsivity, lifetime history of aggression, and novelty seeking were associated with younger age of death by suicide, while increasing levels of harm avoidance were associated with increasing age of suicide. This effect was observed after accounting for age-related psychopathology (current and lifetime depressive disorders, lifetime anxiety disorders, current and lifetime substance abuse disorders, psychotic disorders and cluster B personality disorders). Age effects were not due to the characteristics of informants, and such effects were not observed among living controls. When directly controlling for major psychopathology, the interaction between age, levels of impulsivity, aggression and novelty seeking predicted suicide status while controlling for the independent contributions of age and these traits.


CONCLUSIONS
Higher levels of impulsive-aggressive traits play a greater role in suicide occurring among younger individuals, with decreasing importance with increasing age.
McGirr
A
A
McGill Group for Suicide Studies, Douglas Hospital Research Center, McGill University, Montreal, Canada.
Renaud
J
J
Bureau
A
A
Seguin
M
M
Lesage
A
A
Turecki
G
G
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000374:Aggression / Q000523:psychology*; D002423:Cause of Death; D002648:Child; D015897:Comorbidity; D003625:Data Collection; D005106:Exploratory Behavior; D005260:Female; D006801:Humans; D007175:Impulsive Behavior / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology*; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology / Q000523:psychology; D008875:Middle Aged; D010552:Personality Assessment; D015995:Prevalence; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D013405:Suicide / Q000523:psychology / Q000706:statistics & numerical data*; D013406:Suicide, Attempted / Q000523:psychology / Q000706:statistics & numerical data