Stability of positive and negative symptoms in schizophrenic patients: a 3-year follow-up study

Abstract

The course of negative and positive symptoms was studied in neuroleptic-treated patients over a 3-year period, in consideration also of the initial phase of illness (post-acute or chronic). This study was carried out in a broadly defined schizophrenic sample, in order not to give preference to one diagnostic subgroup over another. Forty-six patients were evaluated every year for 3 years, 23 in the post-acute group and 23 in the chronic group. Aggravations of the Clinical Global Impression (CGI) and of the SANS total score were observed, regardless of the group (chronic or post-acute). This global aggravation confirmed Kraepelin's concept of dementia praecox; moreover, this aggravation was not due to an increase in the number of patients relapsing, or to an aggravation of akinesia. Three types of negative and positive symptom courses were observed: i) the mean sub-scores of positive symptoms, such as hallucinations, delusions, positive formal thought disorders, and of negative symptoms such as flattening affect, avolition/apathy and attentional impairment, did not vary significantly over time in either group; ii) the mean sub-scores of bizarre behavior and alogia fluctuated over time (p < 0.05) and only poverty of speech was perfectly stable among the items constituting alogia; iii) the mean subscores of anhedonia/asociality worsened significantly over time irrespective of the groups (p < 0.05), and among the items constituting anhedonia, recreational interest-activities and intimacy-closeness abilities worsened (p < 0.05 and p < 0.01, respectively). This aggravation was neither due to an increase in neuroleptic doses nor to the duration and chronicity of illness. However, negative symptoms, except anhedonia, can be reversible in some patients. The very strong stability of anhedonia, whatever the group, emphasize the importance of taking anhedonia into account in future diagnostic classifications.