Sex differences in cognitive functioning in patients with bipolar disorder who recently recovered from a first episode of mania: data from the Systematic Treatment Optimization Program for Early Mania (STOP-EM).
BACKGROUND
Studies investigating bipolar disorder (BD) showed that healthy patterns of sex differences in cognitive functioning are altered within this population, but is it unknown whether these alterations are present in BD patients early in their course of illness.


METHODS
Patients with bipolar I disorder (36 males, 38 female), who had recently experienced their first manic or mixed episode were tested along with healthy controls (39 males, 59 females) similar in age, sex and premorbid IQ. Cognitive function was assessed through a comprehensive neuropsychological test battery.


RESULTS
Significant group effects were found in a majority of administered tests (p<0.05) with patients performing worse than healthy controls. Significant sex effects (p<0.05) were observed on tasks of spatial working memory and sustained attention, with males performing better than females. No significant group by sex interaction was found in any of the tasks administered.


CONCLUSIONS
The cognitive battery employed in this study may not have been optimally sensitive in detecting sex differences.


CONCLUSIONS
The results suggest that unlike patients with long standing multi-episode BD or schizophrenia, healthy cognitive sex differences are maintained in patients with early BD, following recovery from a first-episode of mania. These findings highlight the progressive nature of the illness and provide justification for an early intervention.
Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC, Canada V6T2A1; Bipolar Disorder Program and Laboratory of Molecular Psychiatry, National Institute for Translational Medicine, INCT-TM Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Joana
J
Bücker
Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC, Canada V6T2A1.
Swetha
S
Popuri
Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC, Canada V6T2A1; Department of Psychiatry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Bangalore, India.
Kesavan
K
Muralidharan
Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC, Canada V6T2A1.
Jan-Marie
JM
Kozicky
Simon Fraser University, Canada.
Heather A
HA
Baitz
Centre for Complex Disorders, University of British Columbia, Vancouver, Canada.
William G
WG
Honer
Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC, Canada V6T2A1.
Ivan J
IJ
Torres
Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC, Canada V6T2A1. Electronic address: yatham@mail.ubc.ca.
Lakshmi N
LN
Yatham
D000293:Adolescent; D000328:Adult; D001714:Bipolar Disorder / Q000503:physiopathology*; D016022:Case-Control Studies; D003071:Cognition / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011446:Prospective Studies; D012737:Sex Factors; D055815:Young Adult
Bipolar disorder; First episode; Gender; Mania; Neurocognitive functions; Sex