Objectives: To evaluate neuro-cognitive impairment in patients of bipolar affective disorder in the euthymic state of the illness with specific reference to Reaction Time.
Methodology: 30 euthymic patients meeting criterion for Bipolar Affective Disorder according to DSM – IV were matched on a case by case basis with healthy controls on the basis of age, gender, socio-economic status and educational standards. The patient’s socio-demographic data was recorded and details regarding the Bipolar Illness were obtained .The cases and the controls were then tested on the Standardised Reaction Time Apparatus (Chronoscope) to measure their reaction times to sound, light and to a choice stimulus between sound and light, as a measure of cognitive impairment in Bipolar Disorder.
Results: The results revealed that euthymic bipolar affective disorder patients showed cognitive impairment as compared to healthy controls as evidenced by the delayed reaction time in these individuals. The degree of the cognitive impairment was positively correlated with the number of hospitalizations, the number of manic and depressive episodes and the duration of illness. Patients who were receiving Mood stabilizers alone showed less neurocognitive decline than patients receiving a combination of mood stabalizers and antipsychotics and those receiving antipsychotics alone.
Conclusions: Presence of neurocognitive impairment in the euthymic state of the illness supports the “ Trait “ hypothesis i.e. these impairments are a part of the illness thereby challenging the central tenet of complete recovery from bipolar episodes.Reaction Time can be developed as an effective measure of neurocognitive dysfunction owing to ease of measurement.