A Comprehensive Evaluation of Executive Functions Using the Cambridge Neuropsychological Test Automated Battery in People with Major Depressive Disorder

Major depression is a common disease in the world, which is associated with cognitive impairment. Executive functions are among the cognitive functions that are influenced by major depression. This study was conducted to comprehensively evaluate the executive functions of people with major depressive disorder and normal people using the Cambridge Neuropsychological Test Automated Battery (CANTAB).

This case-control study was conducted on 13 patients with major depressive disorder and 13 normal individuals aged 21 to 35 years who were referred to psychology and psychiatry centers in Tehran (Iran) in 2019. The subjects were randomly selected from six centers in four districts of Tehran and then divided into an experimental group and a healthy control group. Both groups were subjected to cognitive assessment using the CANTAB, n-back test as well as Daneman and Carpenter's working memory sentences.

The mean of executive functions was significantly lower in people with major depressive disorder compared to their healthy counterparts (P<0.05). When examining the components of executive functions in both the experimental and control groups, there was a significant increase in the shifting in the total number of errors and the inhibition component in direction errors. In addition, there was a statistically significant decrease in the updating component in errors 1 and error 2 and an increase in time 2. Furthermore, there was a significant increase in the component of working memory maintenance in error as well as the planning component in the average delay (response speed) to the first choice, to correct the error and a decrease in working memory manipulation (P<0.05).

Our findings indicate that the executive functions of people with major depressive disorder are lower than healthy counterparts according to the CANTAB.