Locomotor Movement-Pattern Analysis as an Individualized Objective and Quantitative Approach in Psychiatry and Psychopharmacology: Clinical and Theoretical Implications

Abstract

Psychiatry is the only medical specialty lacking clinically applicable biomarkers for objective quantification of the existing pathology and the subsequent treatment effects at a single-subject level. Based on an original (internationally patented) method for evaluating movement patterns, we have introduced in the everyday clinical practice an easy-to-perform objective and quantitative approach to the individual motor behavior in psychiatric and neurological patients. It involves equilibriometric quantification of the head and body movements during the execution of specific locomotor tasks. For the last 20 years, we have gradually collected a large database from cross-sectional and longitudinal investigations of more than 1000 patients and healthy controls. Comparative analyses have revealed trans-diagnostic similarities among different psychiatric and neurological categories as well as significant within-diagnostic dissimilarities, which can help to separate out subgroups within the same nosological category. Pharmacological challenges and treatment effects permit objective quantification of the normalizing or denormalizing effects of various psychotropic drugs on the individual motor behavior. The computerized locomotor movement-pattern analysis suggests that hyperlocomotion and tachykinesia could be viewed as objectively measurable biomarkers of increased physiological and emotional arousal, supposedly attributable to dopaminergic hyperactivity and/or amygdala hyperactivation, while hypolocomotion and bradykinesia indicate the opposite neurobiological and psychological dysregulation. Analogies with the prominent role of locomotor measures in some well-known animal models of psychiatric disorders advocate for a promising objective translational research in the so far over-subjective fields of psychiatry and clinical psychopharmacology. Most important clinical and theoretical implications of the new approach are discussed.