A STUDY OF CORRELATION OF DEPRESSION AND HIPPOCAMPAL VOLUME

Abstract

INTRODUCTION: Major depressive disorder is a common, severe and debilitating illness with increasing rate of morbidity and mortality. The biological model used to conceptualise the course of depression involves structural changes in hippocampus. Reduced plasticity of hippocampus has been found to be correlated to stress and depression in many studies. Depression is associated with hypercortisolaemia which down-regulates the HPA axis and damages hippocampal neurons. Executive deficits are very common in depression which strongly suggests hippocampal involvement over the course of depressive illness.

AIM: To look for changes in hippocampal volume due to depression.

METHODS: The study will include 60 patients between ages 18-65 interviewed using HAM-D Scale Questionnaire and had MRI Brain with a 3D IR-PREP sequence. In this sequence we acquire the 3D data and reformat hippocampal region and measure antero-posterior superior-inferior and transverse dimension with volume estimate. The data was then be pooled, tabulated and subjected to statistical analysis.

RESULTS AND DISCUSSION: The depressive patients had a significant correlation with Hippocampal Volume which is observed on the both sides and its inversely related to increasing duration and severity. The correlation of Hippocampal Volume with Duration is significant at; For the Right Side (beta=-0.57,p<0.00, R²⁼0.231) and For the Left Side (beta=-0.05, p<0.00, R²=0.268). The correlation of Hippocampal Volume with Severity is significant at; Right Side (beta=-0.038, p<0.002,R²=0.155) and for the Left Side (beta=-0.26, p<0.029, R²=0.08).

CONCLUSION: There is a significant correlation in role of hippocampus and the pathology of depression. It has been found that there is inverse correlation of hippocampal volume and increasing severity and duration of illness.