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 Movement disorders such as parkinsonism in patients treated with antipsychotics are generally attributed to these medications acting through dopamine antagonism. However, parkinsonism has also been reported in antipsychotic-naive patients with schizophrenia, with rates varying from 4% (1) to 17% (2). Investigators have suggested that these movement abnormalities (spontaneous dyskinesia and extrapyramidal symptoms) are intrinsic to the pathophysiology of schizophrenia (1–3). The incidence rate of TD has been reported to be higher among those with affective symptoms (4–6). However, there are no published data on whether individuals with affective symptoms are also more prone to other forms of spontaneous movements. This study set out to establish rates of SP among the different types of psychosis. We hypothesized that the rate would be higher among those with affective symptoms. MethodThe prevalence of parkinsonism was studied in consecutive patients admitted to a first-episode psychosis intervention program in Singapore. The study was approved by the Institutional Ethics Committee, and all patients gave written consent for the study. Inclusion criteria required patients aged between 15 and 40 years who were experiencing their first episode of nonorganic psychosis with no significant physical disorders and with no history of treatment with antipsychotic medication. These patients were assessed with the Simpson–Angus Rating Scale (7) at baseline, and the psychiatric diagnoses were established with the Structured Clinical Interview for DSM-IV–Patient Version (8). Three psychiatrists did the assessments, and the interrater coefficient for the Simpson–Angus scale was 0.82. Sociodemographic data (such as age, sex, and duration of illness) were recorded from interviews with patients and caregivers and from the medical records. Parkinsonism was assessed to be present if the Simpson–Angus score was ³ 0.3 (9). Chi-square tests and Fisher’s exact test were used for categorical data. All analyses were performed with the SPSS (10). Statistical significance was set at P < 0.05.
ResultsA total of 174 patients were examined; of these, 90 (51.7%) were men and 84 (48.3%) were women. The patients’ mean age was 28.1 years, SD 6.7 years. The mean duration of illness was 17 months, SD 30.5 months, with a median of 6 months. Of these patients, 123 (70.7%) were Chinese, 37 (21.3%) were Malay, 9 (5.2%) were of Indian Subcontinent origin, and the remaining 5 (2.9%) were of other ethnic origins. Seventy-five (43.1%) patients were diagnosed with schizophrenia, 42 (24.1%) with schizophreniform disorder, 16 (9.2%) with brief psychotic episode, 12 (6.9%) with psychosis otherwise specified, 8 (4.6%) with schizoaffective disorder, 5 (2.9%) with delusional disorder, and 10 (5.7%) with affective psychosis (5 with bipolar disorder and 4 with major depressive disorder with psychotic symptoms). Only 4 (2.3%) patients (2 Chinese women, 1 Chinese man, and 1 Malay man) had SP. Two were diagnosed with schizoaffective disorder and 2 with schizophreniform disorder. All had rigidity, and 2 had tremors as well. There was a significant difference in the rates of SP in patients with affective psychosis and schizoaffective disorder, compared with those of all other diagnoses (15.4% vs 1.2%; c2 = 10.7, P = 0.001; Fisher’s exact test, P = 0.05). The 2 groups did not differ significantly in age, duration of untreated psychosis, or sex distribution. DiscussionMcCreadie and others (11) reported that, of 37 never- medicated and chronically ill patients with schizophrenia assessed on 2 occasions, 13 (35%) had parkinsonism on at least one occasion. In a prospective study, Chatterjee and others (2) used the Simpson–Angus Rating Scale to examine 89 neuroleptic-naive, first-episode schizophrenia patients and reported that 15 (16.9%) had extrapyramidal signs. Compared with these studies, the prevalence rate of 2.3% in our study suggests that SP is low among Asian patients with first-episode psychosis. Comparison across studies is fraught with difficulties owing to differences in patient population, in definitions of parkinsonism, and in method of assessments. For example, using clinical assessment, Caligiuri and others (3) found no tremors among their subjects; however, with instrumental assessment (a more sensitive tool than clinical examination), they found that 37% of their subjects exhibited subclinical parkinsonian tremor. Our patient population was relatively young and had a comparatively shorter duration of illness. A longer duration of illness could have permitted the emergence of movement disorders. McCreadie and others found that spontaneous parkinsonism fluctuates over time in drug-naive patients with schizophrenia (11). Because this is a cross-sectional study with a single-point assessment, it is possible that the rate we obtained is an underestimate. References1. Puri BK, Barnes TR, Chapman MJ, Hutton SB, Joyce EM. Spontaneous dyskinesia in first episode schizophrenia. J Neurol Neurosurg Psychiatry 1999;66:76–8. 2. Chatterjee A, Chakos M, Koreen A, Geisler S, Sheitman B, Woerner M, and others. Prevalence and clinical correlates of extrapyramidal signs and spontaneous dyskinesia in never-medicated schizophrenic patients. Am J Psychiatry 1995;152:1724–9. 3. Caligiuri MP, Lohr JB, Jeste DV. Parkinsonism in neuroleptic-naive schizophrenic patients. Am J Psychiatry 1993;150:1343–8. 4. Richardson MA, Pass R, Bregman Z, Craig TJ. Tardive dyskinesia and depressive symptoms in schizophrenics. Psychopharmacol Bull 1985;21:130–5. 5. Sachdev PS. Depression-dependent exacerbation of tardive dyskinesia. Br J Psychiatry 1989;155:253–5. 6. Kane JM, Woerner M, Weinhold P, Wegner J, Kinon B, Borenstein M. Incidence of tardive dyskinesia: five-year data from a prospective study. Psychopharmacol Bull 1984;20:387–9. 7. Simpson GM, Angus JWS. A rating scle for extrapyramidal side effects. Acta Psychiatr Scand Suppl 1970;212:11–9. 8. First MB, Spitzer RL, Gibbon M, Williams JBW. Structured Clinical Interview for DSM-IV Axis I Disorders–Patient Edition (SCID-I/P Version 2.0) New York: Biometrics Research Department New York State Psychiatric Institute; 1997. 9. Halliday J, Farrington S, Macdonald S, MacEwan T, Sharkey V, McCreadie R. Nithsdale Schizophrenia Surveys 23: movement disorders: 20 year review. Br J Psychiatry 2002;181:422–7. 10. SPSS Inc. SPSS. Version 10.1. Chicago (Il):SPSS Inc. 11. McCreadie RG, Padmavati R, Thara R, Srinivasan TN. Spontaneous dyskinesia and parkinsonism in never-medicated, chronically ill patients with schizophrenia: 18-month follow-up. Br J Psychiatry 2002;181:135–7. AuthorsManuscript received April 2004, revised, and accepted March 2005 1. Senior Consultant and Chief of Department of Early Psychosis Intervention; Director of Research, Institute of Mental Health, Woodbridge Hospital, Singapore. 2. Research Administrator, Institute of Mental Health and Woodbridge Hospital, Singapore. 3. Associate Consultant, Department of Early Psychosis Intervention, Institute of Mental Health and Woodbridge Hospital, Singapore. Address for correspondence: Dr SA Chong, Institute of Mental Health and Woodbridge Hospital, 10 Buangkok View, Singapore 539747 e-mail: Siow_Ann_Chong@imh.com.sg
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