Introduction: Cognitive effects of novel antipsychotics (AP) as compared to mood stabilizers in bipolar disorder have not been studied in euthymic patients on monotherapy. We compared the cognitive profile of DSM-IV-TR euthymic patients on monotherapy with lithium (Li) , valproic acid (VPA) or a novel AP.
Method: Eutyhmic outpatients on Li (n=19) or VPA (n=14) or a novel AP (n=12) were assessed with a detailed standard battery including clinical and cognitive measures. Groups were similar in terms of gender, age, education, duration and severity of illness, psychotic features, hospitilazation, comorbid physical and psychiatric ilnesses, psychaitric history in the family and severity of residual mood symptoms. Scores were analyzed in a MANOVA model.
Results: Working memory was more impaired in the AP group compared to the Li group (p=0.03). Other between-group differences were not significant. The three groups were also similar in terms of executive functions, verbal memory, psychomotor speed and visuospatial abilities.
Discussion: Relative working memory impairment in the AP group might indicate a side-effect of AP’s or a protective effect of Li. The clinical and sociodemographic similarity of the groups decreases the probability of confounder effects, however, more detailed assessments and follow-up in larger samples are needed for definitive conclusions.