FREE PAPER: Comparative Study of Cognitive Dysfunction in Patients with Bipolar Affective Disorder Receiving Prophylaxis of Oral Sodium Valproate and Lithium

BACKGROUND: Cognitive impairment is a common complaint among patients taking Lithium and Sodium Valproate as mood stabiliser for treatment of BPAD often leading to non-compliance. Previous studies suggest that both Lithium and Na Valproate may cause impairment in memory and psychomotor speed on long term use. AIMS: The evidence is equivocal regarding Mood-stabilisers effect on cognition; hence we conducted a study to test the cognitive functions in euthymic patients of BPAD on Lithium and Na-Valproate monotherapy using comprehensive neuropsychological tests. SETTING AND DESIGN: Cross-sectional assessment of euthymic BPAD done in tertiary neuropsychiatric hospital, on OPD basis. METHOD: Study of 60 euthymic patients of BPAD on monotherapy with mean duration of 7.97 ± 4.72 years on Lithium and 6.27± 3.26 years on Na-Valproate was conducted. Cognitive functions were assessed using Trail making test part A for attention and part B for cognitive flexibility, Digit vigilance test for attention, PGI-BBD memory scale to assess memory and Stroop test for executive function of response inhibition. RESULTS: The patients on Na-Valproate monotherapy were found to have severe dysfunction of attention, cognitive flexibility, delayed, verbal and visual memory. On Na-Valproate, severe dysfunction of delayed, verbal and visual memory and executive function was found. CONCLUSION: The euthymic BPAD patients on long-term Na-Valproate monotherapy were found to have more dysfunction of response inhibition under the domain of executive function than patients on Lithium treatment.