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Background: Functional near-infrared spectroscopy (fNIRS) is being increasingly utilized to visualize the brain areas involved in cognitive activity to understand the human brain better. Its portability and easy setup give it an advantage over other functional brain imaging tools. The current study utilizes fNIRS while performing a Stroop test, which is commonly used to assess the impairment of information selection in depression. Aim: To compare cortical activation during the Stroop test in depressed individuals to healthy controls. Methods: This cross-sectional study compared oxyhemoglobin (OxyHb) concentration changes in 39 individuals with depression to 40 healthy individuals. The Stroop test was construed in an event-related design with an intertrial interval of 2 seconds with jitter. A continuous wave fNIRS system was used for recording the cortical activity at 17 locations. Analysis of fNIRS data was done using statistical parametric mapping (SPM) for estimating general linear model (GLM) coefficients. Further analysis of the mean change of OxyHb concentrations during the 2 seconds after the presentation of congruent and incongruent stimuli was done between the groups using Mann--Whitney U test corrected for multiple comparisons with Bonferroni correction. Results: While the number of errors and correct responses were similar between the groups, the reaction time for correct responses was more in the depression group in comparison to healthy individuals (t = -2.39, P = 0.01). For both healthy and depressive individuals in incongruent versus congruent task contrast, deactivation was seen in the region between the left middle frontal sulcus and frontopolar area of the brain (t = 0.41 and t = 0.21, respectively, P < 0.05). The depressed group had a higher mean change in OxyHb concentration following incongruent stimuli in comparison to the HCs (mean rank: HC = 32.63, depression = 47.56). Conclusion: Our findings indicate that individuals with depression exhibited prolonged reaction times and distinct activation patterns of the frontal cortex compared to healthy individuals. The observed pattern of brain activation for congruent and incongruent tasks among both healthy and depressed individuals aligns with the findings of the prior studies, emphasizing the utility of fNIRS as a valuable instrument for assessing brain activity. [ABSTRACT FROM AUTHOR]

Background: There is a limited number of studies from India investigating the role of transcranial direct current stimulation (tDCS) in treatment-resistant depression (TRD). This clinic-based study reports on the effectiveness of tDCS as an add-on treatment in individuals suffering from TRD. Materials and Methods: Twenty-six right-handed individuals suffering from major depressive disorder who failed to respond to adequate trials of at least two antidepressant drugs in the current episode received tDCS as an augmenting treatment. Twice daily sessions of conventional tDCS were given providing anodal stimulation at the left dorsolateral prefrontal cortex (DLPFC) and cathodal placement at the right DLPFC. A total of 20 sessions were given over 2 weeks. The outcome was assessed based on changes in scores of the Hamilton Rating Scale for Depression (HAMD) and Montgomery-Asberg Depression Rating Scale (MADRS). Results: There was a significant reduction in outcome assessment after tDCS intervention as compared to baseline, with more than 50% of the participants showing response in both scales, which increased further to approximately 77% by the end of 1 month of the follow-up period. Conclusion: Twice daily tDCS sessions with anodal stimulation of left DLPFC and cathodal stimulation of right DLPFC is an effective add-on treatment strategy in individuals with TRD. [ABSTRACT FROM AUTHOR]