Seventy-nine patients with a first episode of psychosis who met the DSM-III-R criteria for schizophrenia or schizophreniform psychosis were assessed over the period of the study. Of these, 50 (63%) were male and 29 were female. Their mean age was 27.7 years (SD=9.7). Forty-nine of these patients were neuroleptic-naive at the time of assessment; the remaining 30 had been medicated for less than 1 month, either having been started on medication before referral by their primary health care physicians or being too ill to cooperate with assessment before treatment began. Seventeen patients (22%) also met the DSM-III-R criteria for drug or alcohol abuse or dependence in the past month. Four patients had comorbid physical illness: one had partial deafness, another had a congenital hand deformity, the third had a history of head injury, and the fourth was receiving interferon treatment for nonmetastatic malignant melanoma. Seventy-seven patients were Caucasian, and two patients were of mixed racial origin.
The mean total AIMS score for the group was 1.6 (SD=2.2, range=0–12). When the criteria of Schooler and Kane were applied, six patients were found to have spontaneous dyskinesia. Five of these were neuroleptic-naive, and one had been treated with neuroleptics for 1 week; all were of Irish origin and free of comorbid physical illness. Two of these patients with spontaneous dyskinesia had comorbid cannabis and alcohol dependence. The topography of their involuntary movements was primarily orofacial; three patients had mild orofacial movements of the tongue, jaw, and lips, and two patients evidenced a mixed topography with jaw and tongue movements (one having moderate severity) in conjunction with mild upper limb movements. One patient had mild upper and lower limb movements only. A further nine patients had mild involuntary movements of one orofacial region but did not meet the Schooler and Kane criteria for spontaneous dyskinesia. The four patients with comorbid physical illness did not have mild involuntary movements in any body area. The rate of spontaneous schizophrenia/schizophreniform psychosis was 7.6% (N=6 of 79; 95% confidence interval=2.8%–15.8%). The rate in the neuroleptic-naive group was 10.2% (N=5 of 49; 95% confidence interval=3.4%–22.2%). Exclusion of patients with current alcohol or drug abuse or dependence had little influence on either rate: 6.5% (N=4 of 62) in the total group and 9.8% (N=4 of 41) in the neuroleptic-naive group.
The mean age at presentation did not differ between the patients with spontaneous dyskinesia and those without (mean=25.3 years, SD=11.6, and mean=27.9 years, SD=9.6, respectively; t=0.63, df=77, p=0.53). There was no significant difference in gender distribution between the group of patients with spontaneous dyskinesia (three male and three female) and the group without (47 male and 26 female) (p=0.66, Fisher’s exact test).
Patients with spontaneous dyskinesia had completed significantly fewer years of education (mean=11.3 years, SD=2.3) than patients without spontaneous dyskinesia (mean=13.3 years, SD=2.4) (t=2.15, df=77, p=0.03). However, in a logistic regression (T2) in which the presence of spontaneous dyskinesia was the dependent variable and age, gender, years of education, treatment status, and current drug or alcohol abuse or dependence were the independent variables, the overall regression model was not significant (-2 log likelihood χ2=8.21, df=5, p=0.15). When we went on to do a stepwise logistic regression using the same variables, years of education discriminated between the groups (Wald χ2=4.26, df=1, p=0.04, after the forward-stepping procedure). However, when we used a Bonferroni correction for the five variables considered in the regression, this failed to reach the required level of significance (corrected p=0.20). In a multiple linear regression (T3) with total AIMS score as the dependent variable and the same independent variables as above, the overall regression model was not significant (F=1.41, df=5, 73, p=0.23, R2=2.6%). After forward stepping, years of education was the only variable related to the total AIMS score (F=4.93, df=1, 77, p=0.03, R2=4.8%). However, again this did not meet the required level of significance after Bonferroni correction (corrected p=0.15).