Childhood-onset bipolar disorder: Evidence for increased familial loading of psychiatric illness.
OBJECTIVE
To determine whether childhood-onset bipolar disorder (BP) is associated with an increased psychiatric family history compared with adolescent-onset BP.


METHODS
Semistructured psychiatric interviews were conducted for 438 youth with BP spectrum disorders. To evaluate the effects of age at onset and psychiatric family history, the sample was divided into childhood-onset BP (age and BP onset <12 years; n = 192), adolescents with early-onset BP (age > or =12 years and BP onset <12 years; n = 136), and adolescents with late-onset BP (age and BP onset > or =12 years; n = 110). Lifetime family history of psychiatric illness was ascertained for first- and second-degree relatives through both direct interview of caretakers and the Family History Screen.


RESULTS
After significant demographic and clinical factors were controlled for, children and adolescents with childhood-onset BP showed higher percentages of positive first-degree family history for depression, anxiety, attention-deficit/hyperactivity, conduct, and substance dependence disorders and suicidal behaviors compared with adolescents with late onset. Subjects with childhood-onset BP also showed elevated familial loading for depression and attention-deficit/hyperactive disorder in second-degree relatives.


CONCLUSIONS
These data support a model that postulates a higher density of familial risk for a broad range of psychopathology in childhood-onset BP.
Rende
Richard
R
Department of Psychiatry and Human Behavior, Brown Medical School, Providence, RI, USA. Richard_Rende@Brown.edu
Birmaher
Boris
B
Axelson
David
D
Strober
Michael
M
Gill
Mary Kay
MK
Valeri
Sylvia
S
Chiappetta
Laurel
L
Ryan
Neal
N
Leonard
Henrietta
H
Hunt
Jeffrey
J
Iyengar
Satish
S
Keller
Martin
M
D000293:Adolescent; D000367:Age Factors; D001714:Bipolar Disorder / Q000175:diagnosis / Q000235:genetics* / Q000523:psychology; D002648:Child; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005820:Genetic Testing; D005838:Genotype; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000235:genetics / Q000523:psychology; D010641:Phenotype