Aerobic Exercise and Hippocampal Plasticity in Young Adults with Depression

Abstract

Major depressive disorder (MDD) is a significant public health problem. Exercise has shown promise in reducing symptoms and promoting brain plasticity in MDD. A relationship between symptom severity, hippocampus volume and N-acetyl-aspartate (NAA) concentration, a marker of neuron density/viability, has been shown. The relationship of these variables to fitness (as assessed by volume of oxygen uptake - VO2 max) is underexplored. In this study, unmedicated, inactive young adults with MDD and healthy controls underwent neuroimaging, fitness and clinical assessments at baseline and after 12-weeks. After 12-weeks of aerobic exercise, VO2max increased and depression scores decreased relative to baseline in participants with MDD. No changes in hippocampal volume or NAA levels were observed, compared to controls. This finding may have resulted from small samples and high variability on the measures of interest. Depression symptom decreases were not related with VO2max changes or exercise compliance.