The Effect of Estrogen on Cognitive Functions in Female Schizophrenics: A Preliminary Study

Kim, Jin Se; Kwak, Dong Il; Jung, In Kwa; Joe, Sook Haeng; You, Young Su

Abstract

OBJECTIVES: There have been many investigations into the evaluation and treatment of cognitive deficits in schizophrenia, because cognitive deficits do not respond well to antipsychotics and may be a very important prognostic factor for social and occupational outcomes. And it has been known that estrogen improves cognitive functions, as proved in animal studies and studies in postmenopausal women and dementia patients. And estrogen has been unvestigated as an etiologic factor of the neuroendocrine abnormalities of schizophrenia. This preliminary study was aimed to investigate the effect of estrogen on cognitive functions of female schizophrenics, as one of the estrogen projects on our institute.
METHODS
The subjects consisted of 30 females with schizophrenia. During the study, all subjects maintained the same dosage of antipsychotics as before the study. Fifteen subjects were given estrogen (EG), and the other fifteen subjects were not(CG). Trail Making Test A and B, Digit Symbol Substitution Test, Finger Tapping Test, Visual continuous Performance Test, Spatial Memory Test, and Wisconsin Card Sorting Test were taken every four weeks from the baseline to the 12th week.
RESULTS
At Baseline, there were no significant differences of ages, duration of illness, antipsychotic dose, ammenorrhea, PANSS, types of schizophrenia, MADRS and CGI, and cognitive function tests between EG and CG. There were no significant improvements of Trial Making Test A & B, Finger Tapping Test, and Visual continuous Performance Test in both groups. But there were significant improvements of Digit Symbol Substitution Test, Spatial Memory Test, and Wisconsin Card Sorting Test (total errors and completed categories) in EG, but not in CG.
CONCLUSION
The authors found that estrogen improved some cognitive functions, such as memory and executive function in EG. But it could not be clearly defined whether those changes are due to the direct effect of estrogen on the cognitive functions, or the improvement of psychotic symptoms, or the generalized enhancing effect of cognitive functions.