Increased intrasubject variability in response time in youths with bipolar disorder and at-risk family members.
OBJECTIVE
Deficits in sustained attention may represent an endophenotype for bipolar disorder (BD). One heritable measure of sustained attention is intrasubject variability in response time (ISV-RT). We tested the hypothesis that, compared with controls, both youths with BD and those at familial risk for the disorder would have increased ISV-RT.


METHODS
Subjects were 28 patients with BD, 26 unaffected youths with a first-degree relative with BD, and 24 control youths without an affected relative, all aged 7 to 17 years. Subjects completed the Flanker Continuous Performance Test.


RESULTS
Bipolar disorder and at-risk youths had increased ISV-RT, compared with the controls. Differences were independent of comorbid psychopathology in youths with BD and present in psychiatrically healthy at-risk youths.


CONCLUSIONS
Increased ISV-RT may be a risk marker for BD. Further research is needed to investigate the neural and genetic underpinnings of this deficit, as well as the specificity of the finding to BD.
Brotman
Melissa A
MA
Rooney
Melissa H
MH
Skup
Martha
M
Pine
Daniel S
DS
Leibenluft
Ellen
E
D000293:Adolescent; D001288:Attention; D001714:Bipolar Disorder / Q000175:diagnosis / Q000235:genetics* / Q000523:psychology; D002648:Child; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics / Q000523:psychology; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010641:Phenotype; D011930:Reaction Time; D012307:Risk Factors