Hippocampal volume alteration in medication-naive depression patients in comparison to healthy individuals: An Indian perspective

Abstract

Context: Depression is the most common mental health problem in all the age groups. However, the exact pathophysiology of this devastating disorder remains an enigma. Many hitherto conflicting studies have focused on volumetric measurement of the hippocampus using magnetic resonance imaging (MRI), but few studies have been conducted in our country. Thus, our study envisages comparing hippocampal volumes of medication-naïve depressed individuals against healthy controls. Materials and Methods: This study was conducted both on patients admitted to the hospital and those attending outdoor clinic fulfilling inclusion/exclusion criteria in a tertiary care hospital. The sample consisted of 25 patients freshly diagnosed as Depressive Episode as per the International Classification of Diseases (ICD-10) and 25 healthy controls. Sociodemographic and clinical history pro forma and Hamilton Rating Scale for Depression were administered on all individuals before obtaining the volumetric measurements of the hippocampi of all individuals using a 1.5 Tesla MRI scanner. Results: Our study indicated right hippocampal volumes (RHVs) of depressed individuals were significantly reduced more so with advancing age. It hinted to the lesser effect of severity of depression on RHVs than in the left hippocampal volumes (LHVs). We found that female patients are more predisposed to RHV loss. However, our study did not reveal any significant difference in LHVs or total hippocampal volumes between depressed individuals and healthy controls. Conclusions: It is one of the exclusive studies which have attempted to shed light on the pathophysiology of depression in relation to its severity and hippocampal volumes in the Indian context.

Keywords

• Depression
• hippocampus
• India
• magnetic resonance imaging
• medication-naïve
• volume