Executive functioning and theory of mind in euthymic bipolar disorder.
OBJECTIVE
To examine the nature of executive deficits in euthymic patients with bipolar disorder (BD).


METHODS
Fifteen euthymic BD patients and 13 controls were administered a battery of executive tasks including verbal fluency, Stroop, Theory of Mind (ToM) tests and selected subtests from the Cambridge Neuropsychological Test Automated Battery (CANTAB). Self-report and clinician ratings of mood and social and occupational functioning were also obtained.


RESULTS
There were no significant differences between BD patients and controls on the primary measures of the following executive tasks: verbal fluency, attentional set-shifting, problem solving or planning. On secondary measures of speed, BD patients were slower to complete the first trial of the Stroop task (p = 0.001). Patients with BD committed more errors across all secondary measures. Patients performed poorly when compared with controls on tests of verbal ToM (p = 0.02), and although they performed non-verbal ToM tasks at a level comparable to controls (p = 0.60), they were slower to initiate a response (p = 0.006). ToM was not significantly correlated with any measure of social and occupational functioning; however it correlated with the achievement scores of the CANTAB Stockings of Cambridge task (Pearson's r = 0.68, p < 0.01).


CONCLUSIONS
Deficits found in euthymic bipolar patients suggest fronto-subcortical pathway dysfunction. This is consistent with other neuropsychological and neuroimaging research that points to a trait deficit in BD. Further investigation is necessary perhaps using more real-world tests.
Olley
Amanda L
AL
School of Psychiatry, Black Dog Institute, University of New South Wales, Sydney, NSW, Australia.
Malhi
Gin S
GS
Bachelor
Jennifer
J
Cahill
Catherine M
CM
Mitchell
Philip B
PB
Berk
Michael
M
D000328:Adult; D001288:Attention; D001714:Bipolar Disorder / Q000503:physiopathology* / Q000523:psychology; D003072:Cognition Disorders / Q000175:diagnosis* / Q000523:psychology; D032882:Comprehension; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D012938:Social Perception