Symptomatic determinants of insight in schizophrenia spectrum disorders

Impaired insight in schizophrenia spectrum disorders has been linked to several psychopathologic features including positive symptoms, although not all dimensions of psychopathology have been studied and confounds from other symptoms have not been ruled out. In addition, the nature of the association between insight and specific positive symptoms, in particular delusions, remains unclear. The present investigation examined whether, in patients with schizophrenia spectrum disorders insight is associated with specific symptom dimensions including delusional severity. The factor structure was determined from scores of 151 patients rated on the Signs and Symptoms of Psychotic Illness scale. Associations of the Signs and Symptoms of Psychotic Illness insight item with the resulting components and delusions were assessed using regression-based methodology. Principal component analysis revealed 4 orthogonal symptom clusters. Correlational analyses demonstrated that only depression/anxiety and psychomotor excitation were significantly related to insight. Hierarchical regression indicated that delusions explained unique variance in insight over and above depression/anxiety and psychomotor excitation. These results suggest that depression/anxiety is associated with better insight and that psychomotor excitation and delusions are associated with poorer insight.