The effect of exercise on frontoparietal network connectivity in individuals with depressive symptoms

Depression is one of the most pervasive and burdensome psychiatric disorders globally. This is due, in part, to significant functional impairments associated with deficits in cognitive functioning, such as executive dysfunction. Although there are effective antidepressant and psychological treatments for depression, there are also significant barriers to adhering to these treatments, such as side-effects and cost. Exercise has been shown to be an effective and accessible treatment for depression, and previous literature has demonstrated that it increases cognitive functioning broadly, and executive functioning specifically. One of the potential mechanisms thought to underlie the deficits in executive functioning associated with depression is hypoconnectivity within the frontoparietal network (FPN). Importantly, exercise has been shown to increase FPN resting state functional connectivity. The current study examined whether an 8-week exercise intervention, as compared to an active control stretch condition, decreased depressive symptom severity and increased FPN functional connectivity in individuals with depressive symptoms. Furthermore, it explored whether baseline depressive symptom severity moderated the effects of the interventions on resting state functional connectivity within the FPN. Results indicated that both the exercise and stretch conditions were associated with a statistically and clinically significant reduction in depressive symptom severity. Additionally, baseline depression moderated the effects of stretching on FPN functional connectivity, such that individuals in this condition with moderate to severe depressive symptoms experienced an increase in functional connectivity from pre- to post-intervention. These results demonstrate that both exercise and stretching may be effective treatments for depression, as well as establish a new line of research associating stretching, baseline depressive symptom severity, and FPN functional connectivity. Future research should examine the extent to which changes in FPN neural connectivity underlie changes in executive functioning performance in depressed individuals across exercise and stretch conditions.M.S.Includes bibliographical reference