Neural and Behavioral Predictors of Psychosis

Although psychosis is a hallmark of schizophrenia, psychotic symptoms are not unique to schizophrenia. A subset of individuals who chronically abuse methamphetamine [MA] also develop severe recurrent psychotic symptoms commonly termed MA psychosis. These symptoms are often associated with high levels of psychiatric hospitalization and serious social dysfunction. Clinically the psychotic symptoms of MA psychosis and schizophrenia are striking in their similarity. The nature and severity of MA psychosis can be debilitating, often persisting long after cessation of drug use and in some cases eventually meet criteria for a primary psychotic disorder, suggesting that MA use may be a risk factor for schizophrenia in vulnerable individuals. Although psychotic symptoms are well documented in a subset of MA abusers, little is known about neural mechanisms underlying the vulnerability to develop psychosis in MA users. Furthermore, little is known about why psychotic symptoms persist after cessation of drug use in some MA abusers, but not in others. In our research program, we are utilizing fMRI and MRS imaging techniques in conjunction with targeted cognitive measures of prefrontal function, assessments of childhood attention function as well as genetic sampling to identify risk markers reflecting cortical function that may be linked to predictors of psychotic symptoms. As neurobiological models propose the existence of common neural circuits underlying the neuropathology of both schizophrenia and addiction (i.e. MA abuse), behavioral and neuroimaging data from chronic MA abusers who experience MA psychosis may yield rich data regarding the neural and behavioral predictors of psychosis applicable to other psychiatric populations.