A controlled family study of children with DSM-IV bipolar-I disorder and psychiatric co-morbidity.
BACKGROUND
To estimate the spectrum of familial risk for psychopathology in first-degree relatives of children with unabridged DSM-IV bipolar-I disorder (BP-I).


METHODS
We conducted a blinded, controlled family study using structured diagnostic interviews of 157 children with BP-I probands (n=487 first-degree relatives), 162 attention deficit hyperactivity disorder (ADHD) (without BP-I) probands (n=511 first-degree relatives), and 136 healthy control (without ADHD or BP-I) probands (n=411 first-degree relatives).


RESULTS
The morbid risk (MR) of BP-I disorder in relatives of BP-I probands (MR=0.18) was increased 4-fold [95% confidence interval (CI) 2.3-6.9, p<0.001] over the risk to relatives of control probands (MR=0.05) and 3.5-fold (95% CI 2.1-5.8, p<0.001) over the risk to relatives of ADHD probands (MR=0.06). In addition, relatives of children with BP-I disorder had high rates of psychosis, major depression, multiple anxiety disorders, substance use disorders, ADHD and antisocial disorders compared with relatives of control probands. Only the effect for antisocial disorders lost significance after accounted for by the corresponding diagnosis in the proband. Familial rates of ADHD did not differ between ADHD and BP-I probands.


CONCLUSIONS
Our results document an increased familial risk for BP-I disorder in relatives of pediatric probands with DSM-IV BP-I. Relatives of probands with BP-I were also at increased risk for other psychiatric disorders frequently associated with pediatric BP-I. These results support the validity of the diagnosis of BP-I in children as defined by DSM-IV. More work is needed to better understand the nature of the association between these disorders in probands and relatives.
Wozniak
J
J
Clinical and Research Program in Pediatric Psychopharmacology and Adult ADHD at Massachusetts General Hospital, Boston, MA 02114, USA. jwozniak@partners.org
Faraone
S V
SV
Mick
E
E
Monuteaux
M
M
Coville
A
A
Biederman
J
J
D000987:Antisocial Personality Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D001008:Anxiety Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D001714:Bipolar Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D002648:Child; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004311:Double-Blind Method; D005190:Family / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D011618:Psychotic Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D012307:Risk Factors; D012720:Severity of Illness Index