Neuro-cognitive functions in patients of major depression

Earlier studies have shown conflicting results regarding impairment of executive functions in patients of major depression. In the present study, subjects were divided into following groups-Group 1 (19 Males & 11 females, age 18-45 years) consisting of patients of major depression diagnosed on the basis of DSM IV criteria and Group 2 (20 Males & 10 females, age 18-45 years) consisting of healthy subjects who had been screened for any sub-psychiatric illness by standardized hindi version of Goldberg's General Health Questionnaire (G.H.Q.). All the Group 1 & Group 2 subjects were rated on Hamilton Rating Scale for Depression (HAM-D) and then administered Neuro-cognitive test battery consisting of Letter Cancellation test, Trail Making test 'A' & 'B', Ruff Figural Fluency test, Forward & Reverse Digit Span test for assessing following cognitive domains: Attention span, visuo-motor scanning, short term memory and executive functions like working memory, information manipulation, set-shifting strategy analysis etc. Results showed significant impairment on all the studied neuro-cognitive parameters in Group 1 subjects as compared to Group 2 subjects, which demonstrate significant impairment of attention, visuomotor speed, immediate verbal memory, short-term retentive capacity and executive functions (strategic planning, attentional set shifting and working memory) in patients of major depression. It may probably be due to the disruption of dorso-lateral prefrontal cortex (dlpfc) and orbito-frontal networks in patients of major depression.