Neural correlates of disbalanced motor control in major depression

BackgroundMotor retardation is a common symptom of major depressive disorder (MDD). Despite the existence of various assessment methods, little is known on the pathobiology of motor retardation. We aimed to elucidate aspects of motor control investigating the association of objective motor activity and resting state cerebral blood flow (CBF).MethodsNineteen control subjects and 20 MDD patients were investigated using arterial spin labeling (ASL) at 3 T in the morning to quantify resting state CBF. Afterwards wrist actigraphy was recorded for 24 h. CBF, group and activity level (AL) were entered into a whole brain general linear model.ResultsMDD patients had reduced AL. Both groups had linear associations of AL and CBF in bilateral rostral prefrontal cortex. Groups differed in four clusters associated with motor control. In controls a positive association was found in the left caudal cingulate zone (CCZ) and an inverse association in the right external globus pallidus (GPe). MDD patients had positive associations in the right orbitofrontal cortex and inverse associations in the left supplemental motor area.LimitationsPatients were on antidepressant medication.ConclusionsThe pattern of associations between CBF and AL suggest disbalanced motor control in MDD. Findings are in line with the hypothesis of dopamine deficits contributing to motor retardation in MDD.