Patients in the early stages of bipolar disorder show the same gender differences in cognitive functioning as mentally healthy individuals, findings from the STOP-EM trial show.
The current findings from STOP-EM (Systematic Treatment Optimization Program for Early Mania), along with those of previous studies, therefore highlight “the potentially progressive nature of the illness,” says the team led by Lakshmi Yatham, from the University of British Columbia in Vancouver, Canada.
“It is possible that a significant cognitive insult must first occur before sex differences in cognitive functioning veer away from healthy patterns,” the researchers write in the Journal of Affective Disorders.
A total of 74 bipolar I disorder patients (36 men) who had recently experienced their first manic or mixed episode and 98 mentally healthy individuals (39 men), who were similar in age and premorbid IQ, completed a neuropsychologic test battery. This assessed executive function, attention, working memory, verbal memory, and verbal fluency.
The patients performed significantly worse than mentally healthy individuals on most of the tests. And in both groups, men performed significantly better than women on measures of sustained attention and spatial working memory.
However, there were no group by gender interactions, in that the cognitive differences between men and women were the same in the first-episode mania patients as in the mentally healthy participants.
“Given that cognitive impairment appears to be similar between men and women in first-episode samples, these findings may help identify a time point for customized therapeutic intervention,” say the researchers.
They also point out that if gender differences in cognitive performance remain in the early stages of bipolar disorder, it might be that neuroanatomic sexual dimorphisms in the brain are also maintained.
This article first appeared on ‘News Medical’ on November 14 2013.