Executive functions in major depressive disorder

BackgroundIt is reported that executive functions are impaired in a variety of neuropsychiatric syndromes, including depressive disorders. Studies on executive functions in depressive disorders are inconclusive. MethodsA total of 50 drug naïve patients with major depressive disorder were included in the study. The severity of depression was measured using the Hamilton Depression Rating Scale (HAM-D), and executive functions were assessed using the Digit Symbol Substitution Test, Digit Vigilance Test, Controlled Oral Word Association Test, Animal naming test, Verbal N back (1&2) test, Trail making test A & B and Stroop test as per the NIMHANS Neuropsychology Battery 2004 manual. ResultsThe mean age of the sample was 31.9 years. Females constituted 60% of the sample. A majority were Hindus, nearly 75% were from semi-urban areas, 66% were married, and 58% had a college education. Depression was associated with poor performance on executive functions except for working memory and set shifting. Older age, greater severity of depression, a longer duration of illness and the duration of the present episode were associated with poor performance on executive functions. A higher level of education was associated with better performance on executive functions. ConclusionsThis cross-sectional assessment suggests that some aspects of executive functions are impaired in patients with major depressive disorder. Further studies in remitted patients, controlled for age, and education level are suggested.