Negative symptoms across psychotic spectrum disorders

Abstract

Background and objectives: We aimed to study the psychopathological profile in different dis- orders across the psychotic continuum and to demonstrate that negative symptoms are not so rare in delusional disorder, as it was traditionally considered. Methods: This was an observational study utilizing a sample of 112 patients with a psychotic disorder (delusional disorder, schizophrenia or schizoaffective disorder). The Positive and Neg- ative Syndrome Scale (PANSS) was used to ascertain psychopathological symptoms. One-way ANOVA analyses and post hoc comparisons using the Bonferroni correction were carried out to compare illness duration and PANSS indices. Additionally, t-tests were performed to explore the difference between positive and negative symptomatology in the delusional disorder group. Results: Clinical groups were statistically similar in General PANSS scores, but they differed significantly, in Positive, Negative and Composite PANSS scores. Negative symptoms existed in all three psychotic categories, although they were less prominent in delusional disorder. Positive symptoms were also present in all three categories but were significantly more apparent among schizoaffective disorder patients. Conclusions: Our results support the notion of a psychopathological gradient across the psy- chosis continuum from patients with delusional disorder, at one extreme of the scope, to those with schizoaffective disorder, at the other. More importantly, we have found out that in delu- sional disorder, negative symptoms do exist and are of similar intensity as positive symptoms.