Grip Strength as a Marker of Brain Network Integrity and Well-Being in Early Psychosis

What is it about?

We identified shared brain circuitry in the Default Mode Network (DMN) responsible for grip strength and overall function and well-being using an agnostic, data-driven, connectome-wide analysis. Using data from the multi-site Human Connectome Project for Early Psychosis (HCP-EP, n=206) of individuals with early psychosis and healthy participants, we performed a multivariate pattern analysis of the entire connectome to identify brain circuits linked to grip strength, overall function, and well-being. We observed that higher grip strength was correlated with greater connectivity from multiple brain regions to the DMN. Given the associations between grip strength and well-being, we then repeated this data-driven, connectome-wide analysis to determine if we would identify similar brain correlates for grip strength and well-being – and we did. We identified significant relationships between the same brain regions and their connectivity patterns to the DMN that were related to well-being, overall function, and grip strength. These results have dramatic implications for treatment of psychomotor function in psychotic disorders, as they suggest a unifying role of DMN connectivity in psychomotor disturbance, overall function, and well-being.

Featured Image

Photo by Kelly Sikkema on Unsplash

Photo by Kelly Sikkema on Unsplash

Why is it important?

This manuscript answers a longstanding question in the field: What is the underlying neurobiological mechanism of psychomotor disturbance in psychiatric disorders? Psychomotor disturbance is highly prevalent across psychiatric disorders and has many manifestations, e.g., catatonia, psychomotor retardation, psychomotor agitation, disorganized behavior, and repetitive behaviors or stereotypies. Moreover, there has been an exponential increase in the interest to understand psychomotor processes in disease pathology — the fundamental nature of the motor system enhances our ability to link psychological processes to brain to symptoms, promoting clinically useful targets for intervention. Grip strength is one measure of motor function that has been associated with all-cause mortality and overall well-being. It has been assumed that associations between grip strength and well-being are purely related to mechanical impairments reflective of overall poorer physical health. Therefore, the brain correlates of grip strength have been presumed to lie in the motor system, so previous brain analyses are frequently restricted to motor regions. However, a unifying brain circuit explanation linking grip strength and overall well-being has remained elusive until now. Ours is the first analysis to link grip strength and well-being to alterations in resting-state functional connectivity.