Depressive and anxiety symptoms in patients with schizophrenia and schizophreniform disorder
Background: Symptoms of depression and anxiety are frequently encountered in the course of schizophrenia and are of considerable clinical importance. They may compromise social and vocational functioning, and they are associated with an increased risk of relapse and suicide. Various treatment approaches have been reported to be successful. Method: The sample comprised 177 patients with DSM-III-R or DSM-IV schizophrenia or schizophreniform disorder who were participants in multinational clinical drug trials at our academic psychiatric unit over a 7-year period and who were assessed by means of the Positive and Negative Syndrome Scale (PANSS). Analysis was performed on baseline PANSS scores. The depression/anxiety score was compared in the men and women, first-episode and multiple-episode patients, and those with predominantly positive and negative syndromes. Correlations were sought between depression/anxiety scores and age, total PANSS score, positive score, negative score, general psychopathology score, and treatment outcome. Multivariate analysis was applied to determine contributions of individual variables toward depression/anxiety and outcome scores. Results: Depression and anxiety symptoms were more severe in women (p = .007), first-episode patients (p = .02), and those with predominantly positive symptoms (p < .0001). Depression/anxiety scores were significantly correlated to age (r =-0.31, p < .0001), PANSS positive scores (r = 0.39, p < .0001), and treatment outcome (r = 0.25, p = .006). Multivariate analysis bore out these results, with the exception that first episode was not a significant predictor of depression and anxiety scores. Conclusion: PANSS depressive/anxiety scores were generally low in our sample, perhaps because patients with schizoaffective disorder were excluded. The finding that these symptoms were more prominent in women and first-episode patients is in keeping with previous literature. The higher scores in first-episode patients are likely due to the higher positive symptom scores in these patients. The association between depressive/anxiety scores and positive symptoms but not with negative symptoms points to a specific relationship between affective symptoms and the positive symptom domain of schizophrenia. The presence of depressive and anxiety symptoms may predict a more favorable outcome to treatment, although this may only apply to the acute exacerbations of the illness.