Neurocognitive functioning in the early stages of bipolar disorder: visual backward masking performance in high risk subjects.
BACKGROUND
Cognitive deficits, including deficits in early information processing, are associated with remitted bipolar disorder. The temporal relationship between these deficits and the clinical course is not known. The current study investigated whether or not deficits in early information processing were present before the onset and/or during the early stages of bipolar disorder.


METHODS
Unaffected and remitted high risk offspring of well-characterized bipolar parents completed a visual backward masking task. For comparison we included a cohort of unaffected offspring of well parents and a clinically referred group of remitted bipolar patients.


RESULTS
There was no evidence of a deficit in early information processing in well high risk subjects. As expected, the referred patient group had the highest error rates. After excluding the patients, interaction effect showed that the affected remitted high risk subjects performed differently in terms of error rates than unaffected high risk and control subjects. There were no significant differences in response times across study groups. Exploratory analyses revealed an association between a lifetime history of psychosis and increased errors on the task.


CONCLUSIONS
There was no evidence of a vulnerability in early information processing in offspring at risk for bipolar disorder. However, there were emergent changes in performance in the affected remitted high risk group. Psychosis appears to be an important clinical correlate associated with cognitive deficits. Mapping of the early course of bipolar disorder and associated changes in cognition has important implications for establishing critical periods for intervention.
Duffy
Anne
A
Department of Psychiatry, Dalhousie University, Halifax, NS, Canada. anne.duffy@dal.ca
Hajek
Tomas
T
Alda
Martin
M
Grof
Paul
P
Milin
Robert
R
MacQueen
Glenda
G
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001714:Bipolar Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology*; D002170:Canada / Q000453:epidemiology; D016241:Child of Impaired Parents / Q000523:psychology*; D003072:Cognition Disorders / Q000453:epidemiology / Q000523:psychology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010290:Parents; D010470:Perceptual Masking; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance; D011930:Reaction Time; D013997:Time Factors; D014786:Vision Disorders / Q000523:psychology; D014796:Visual Perception; D055815:Young Adult