What Can Different Motor Circuits Tell Us About Psychosis? An RDoC Perspective

Abstract

Signs of motor dysfunction are evidenced across a range of psychiatric disorders including schizophrenia. Historically, these features have been neglected but emerging theoretical and methodological advancements have shed new light on the utility of considering movement abnormalities. Indeed, the National Institute of Mental Health Research Domain Criteria initiative has recently met to develop a Motor Systems Domain. This reflects a growing appreciation for the enhanced reliability and validity that can come along with evaluating disturbances relevant to psychiatric illnesses from multiple levels of analysis, and conceptualizing these domains with respect to the complexity of their role in a broader integrated system (ie, weighing contributions and interactions between the cognitive, affective, and motor domains). This article discusses motor behaviors and seeks to explain how research into basal ganglia, cerebellar, and cortico-motor circuit function/dysfunction, grounded in brain circuit-motor behavior relationships, can elucidate our understanding of pathophysiology, provide vital links to other key systems of interest, significantly improve identification and classification, and drive development of targeted individualized treatments.

Keywords: RDoC; basal ganglia; cerebellum; cortico-motor circuits; motor; movement abnormalities; psychosis; schizophrenia.

Fig. 1.

The figure shows the relevant motor circuits for psychosis. (A) Basal ganglia circuit. GPi and e: Globus pallidus internal and external; STN = subthalamic nucleus. (B) Cerbellar-thalamo-cortical circuit. Here, we show the cerebello-thalamo-motor. While the cerebello-thalamo-frontal circuit was originally noted by Andreasen and colleagues as being implicated in patients with schizophrenia, more recent work, including our own, has demonstrated that the cerebello-thalamo-motor circuit is also impacted in this population, and relates to deficits in sensorimotor integration. (C) Cortico-motor circuits. Multiple areas of the frontal and parietal cortices interact to control and influence movement. Notably, these regions also interact with the subcortical systems in (A) and (B).