Further evidence of unique developmental phenotypic correlates of pediatric bipolar disorder: findings from a large sample of clinically referred preadolescent children assessed over the last 7 years.
BACKGROUND
A comparison of the prevalence, clinical correlates, and patterns of comorbidity among children with bipolar disorder (BPD) assessed in the early 1990s (1st cohort) with those evaluated over the last 7 years (2nd cohort).


METHODS
Subjects in both cohorts were children aged <or=12 years referred to a child psychiatry service and evaluated with identical assessment methods. Children with a DSM-III-R BPD diagnosis (1st cohort, n=43; 2nd cohort, n=129) were identified. For comparison purposes, we used attention-deficit/hyperactivity disorder (ADHD) children without BPD referred to the same clinic during the same time period (1st cohort, n=164; 2nd cohort, n=450).


RESULTS
Analogous to 1st cohort findings, 2nd cohort results showed that (1) mania was identified in 17% of subjects; (2) the clinical picture was predominantly irritable and mixed, and the course was chronic; (3) BPD children frequently met criteria for major depression, ADHD, psychosis, and anxiety disorders; and (4) BPD children had high rates of psychiatric hospitalization and had evidence of severely impaired psychosocial functioning.


CONCLUSIONS
These findings confirm that pediatric BPD is a severe clinical disorder afflicting a sizable number of referred preadolescent children. Its unique phenotypic features and patterns of comorbidity support the hypothesis that clinically referred pediatric bipolar disorder represents a very severe developmental subtype of bipolar disorder.
Biederman
Joseph
J
Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA. biederman@partners.org
Faraone
Stephen V
SV
Wozniak
Janet
J
Mick
Eric
E
Kwon
Anne
A
Aleardi
Megan
M
D017668:Age of Onset; D001008:Anxiety Disorders / Q000150:complications / Q000523:psychology; D001714:Bipolar Disorder / Q000150:complications / Q000453:epidemiology / Q000523:psychology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D019964:Mood Disorders / Q000150:complications / Q000523:psychology; D010641:Phenotype; D015995:Prevalence; D011379:Prognosis