Deconstructing negative symptoms of schizophrenia: Avolition–apathy and diminished expression clusters predict clinical presentation and functional outcome

Abstract

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.

The Hierarchical Taxonomy of Psychopathology (HiTOP): A Dimensional Alternative to Traditional Nosologies

“…Factor analyses of these measures have identified three symptom dimensions: reality distortion, disorganization, and negative (Andreasen et al, 1995;Blanchard & Cohen, 2006;Grube et al, 1998). New research indicates that it is informative to subdivide negative symptoms into inexpressivity and avolition-apathy (Kotov et al, 2016;Kring et al, 2013;Strauss et al, 2012Strauss et al, , 2013, resulting in four homogenous components overall. Novel measures, such as the Clinical Assessment Interview for Negative Symptoms (CAINS; Kring et al, 2013) and the Brief Negative Symptom Scale (BNSS; Kirkpatrick et al, 2011), have been developed to provide reliable assessment of the two dimensions of negative symptoms, but are more narrow in scope than the SANS.…”

Ventral striatal hypoactivation is associated with apathy but not diminished expression in patients with schizophrenia

“…[3][4][5] Despite these consequences, current knowledge about the underlying pathophysiology remains limited, hindering the development of effective treatment strategies.…”

“…2,5,6 First, a motivational dimension, which we refer to as apathy, combines anhedonia, avolition and asociality. Second, a diminished expression dimension includes blunted affect and alogia.…”

The association of neurocognitive impairment with diminished expression and apathy in schizophrenia

“…We refer to this dimension as apathy. Diminished expression and apathy have been shown to differentially relate to functional outcome (Strauss et al, 2013), decision-making , or neural reward processing Kirschner et al, 2015), potentially indicating differences in underlying mechanisms. In line with this, studies have investigated the cognitive correlates of diminished expression and apathy separately.…”