Deconstructing negative symptoms of schizophrenia: avolition-apathy and diminished expression clusters predict clinical presentation and functional outcome.

BACKGROUND: Previous studies indicate that negative symptoms reflect a separable domain of pathology from other symptoms of schizophrenia. However, it is currently unclear whether negative symptoms themselves are multi-faceted, and whether sub-groups of patients who display unique negative symptom profiles can be identified. METHODS: A data-driven approach was used to examine the heterogeneity of negative symptom presentations in two samples: Study 1 included 199 individuals with schizophrenia assessed with a standard measure of negative symptoms and Study 2 included 169 individuals meeting criteria for deficit schizophrenia (i.e., primary and enduring negative symptoms) assessed with a specialized measure of deficit symptoms. Cluster analysis was used to determine whether different groups of patients with distinct negative symptoms profiles could be identified. RESULTS: Across both studies, we found evidence for two distinctive negative symptom sub-groups: one group with predominantly Avolition-Apathy (AA) symptoms and another with a predominantly Diminished Expression (DE) profile. Follow-up discriminant function analyses confirmed the validity of these groups. AA and DE negative symptom sub-groups significantly differed on clinically relevant external validators, including measures of functional outcome, premorbid adjustment, clinical course, disorganized symptoms, social cognition, sex, and ethnicity. CONCLUSIONS: These results suggest that distinct subgroups of patients with elevated AA or DE can be identified within the broader diagnosis of schizophrenia and that these subgroups show clinically meaningful differences in presentation. Additionally, AA tends to be associated with poorer outcomes than DE, suggesting that it may be a more severe aspect of psychopathology.

Differential patterns of premorbid social and academic deterioration in deficit and nondeficit schizophrenia.

Numerous studies indicate that social dysfunction is associated with negative symptoms of schizophrenia during the chronic phase of illness. However, it is unclear whether social abnormalities exist during the premorbid phase in people who later develop schizophrenia with prominent negative symptoms, or whether social functioning becomes progressively worse in these individuals from childhood to late adolescence. The current study examined differences in academic and social premorbid functioning in people with schizophrenia meeting criteria for deficit (i.e., primary and enduring negative symptoms) (DS: n = 74) and non-deficit forms of schizophrenia (ND: n = 271). Premorbid social and academic functioning was assessed for childhood, early adolescence, and late adolescence developmental periods on the Premorbid Adjustment Scale (PAS). Results indicated that both DS and ND participants showed deterioration in social and academic functioning from childhood to late adolescence. However, while ND schizophrenia demonstrated greater deterioration of academic compared to social premorbid functioning from childhood to late adolescence, the DS group exhibited comparable deterioration across both premorbid domains, with more severe social deterioration than the ND group. Findings suggest that people with DS show poorer social premorbid adjustment than those with ND as early as childhood, and are particularly susceptible to accelerated deterioration as the onset of schizophrenia becomes imminent. Thus, poor premorbid social adjustment and significant social deterioration from childhood to adolescence may be a hallmark feature of people who later go on to develop prominent negative symptoms and a unique marker for the DS subtype of schizophrenia.