Motor dysfunction and risk for schizophrenia

Motor dysfunction is associated with schizophrenia, and recent longitudinal studio, indicate that it precedes the onset of clinical symptoms. Of parti cular interest is the heightened occurrence of involuntary movements, which are apparent as early as infancy and suggest the presence of subcortical b rain abnormalities. In this article, we present the results of a study of s pontaneous movements in adolescents with schizotypal personality disorder ( SPD). SPD is a syndrome that has been shown to be genetically linked with s chizophrenia and is often observed prior to the early adult onset of schizo phrenia. Systematic coding of videotapes of diagnostic interviews revealed that the SPD group showed significantly more involuntary movements of the h ead, trunk, and upper limbs than did normals and adolescents with other per sonality disorders. There were no diagnostic group differences in the rate of voluntary movements. Salivary cortisol, measured before the interview, w as positively correlated with involuntary movements. Taken together, the fi ndings provide further support for the hypothesized etiologic relation betw een SPD and schizophrenia. Based on a neural diathesis-stress model, potent ial underlying mechanisms are discussed.