Grant: Operating Grant

Drug-induced parkinsonism, featuring resting tremor, motor slowing, and body stiffness, remains an unacceptable and frequent complication in about one third of patients treated for schizophrenia with antipsychotic drugs. It typically occurs shortly after drug initiation, often recovering following drug readjustment or withdrawal. However, other individuals with chronic schizophrenia display delayed-onset, persistent parkinsonism, and are thought to suffer from Parkinson's disease. The body of data supporting this hypothesis is thin at present. Since the mechanisms underlying parkinsonism in chronic schizophrenia have not been thoroughly investigated, the condition is not well treated and affects quality of life. In this proposal, clinical markers targeting non-motor aspects of parkinsonism (changes in smell, pain threshold, and sleep architecture), as well as chemical brain scanning markers, will be assessed in patients treated for chronic schizophrenia over 50 years of age, to determine whether those with parkinsonism really suffer from Parkinson's disease. This project may well challenge our concepts about the cause of parkinsonism in chronic schizophrenia. The original data generated may provide ground work to improve treatment strategies.