Comparative change in P300 indices following antidepressant treatment in patients with major depressive disorder

Cognitive disturbance is seen in patients with major depressive disorder (MDD). Event-related potential can assist in measuring the neurocognition, and P300 is the most commonly used noninvasive electrophysiological parameter for measuring cognition.

The aim of this study is to assess the baseline P300 parameters, Hamilton Rating Scale for Depression (HAM-D), and Montgomery-Asberg Depression Rating Scale (MADRS) scores and compare them with their levels after 3 months of antidepressant therapy.

a longitudinal study was done on total 24 diagnosed cases of major depression who underwent P300, HAM-D, and MADRS assessment in the gap of 3 months before and after starting antidepressant therapy.

Newly diagnosed cases of MDD patients were assessed using HAM-D and MADRS for severity rating. P300 assessment was also carried out with auditory oddball paradigm using Nihon Kohden NCV-SMG-EP system. The assessments were repeated after 3 months of antidepressant treatment.

The Wilcoxon test was used to compare mean values of P300 parameters, HAM-D, and MADRS score. Spearman correlation analysis was done to study the association between various parameters of P300 and HAM-D and MADRS score before and after treatment of 3 months of antidepressant therapy.

Significant difference is shown in various parameters P300 except for A11-P300 amplitude and A31-P300 amplitude. A significant difference was shown in HAM-D and MADRS scores. No significant correlation was seen between other P300 parameters and HAM-D and MADRS scale before as well as after antidepressant therapy.

P300 may be used as an index to evaluate the response to antidepressant treatment in patients with MDD.