Differential improvement of negative-symptom subfactors after cognitive remediation in low-functioning individuals with schizophrenia

Abstract

BackgroundNegative symptoms and cognitive deficits have a substantial predictive value for functional deficits and recovery in schizophrenia. However, the relationship between negative symptoms and cognitive abnormalities is unclear possibly due to the heterogeneity of negative symptoms. This study used the model of expressive and experiential negative symptoms subfactors to decrease this heterogeneity. It examined these subfactors and cognition before and after treatment with computerized cognitive remediation training (CRT) in chronically-hospitalized individuals with psychosis and predominant negative symptoms.MethodsSeventy-eight adult participants with a DSM-IV-TR diagnosis of schizophrenia or schizoaffective disorder were enrolled in a 12-week CRT program. Assessments of demographic and illness variables, baseline and endpoint assessments of psychopathology (Positive and Negative Syndrome Scale) and cognition (MATRICS Consensus Cognitive Battery - MCCB) were conducted.ResultsThe baseline expressive negative subfactor was associated with Processing Speed (r = −0.352, p ≤ 0.001) and Reasoning/Problem Solving (r = −0.338, p ≤ 0.001). Following CRT, there was a significant decrease in the experiential negative subfactor (p < 0.01) but not of the expressive negative subfactor. Change in MCCB domains after CRT accounted for 51.1% and 50.2% of the variance of change in expressive and experiential negative subfactor scores, respectively. For both subfactors, Visual Learning was a significant predictor of change (p < 0.05).ConclusionOur findings suggest that CRT has benefits for negative symptoms in very low-functioning patients and that this change may be in part mediated by change in cognitive functions after CRT.

Negative Symptom Domains Are Associated With Verbal Learning in Adolescents With Early Onset Psychosis

“…One line of research points to cognitive deficits underlying symptoms of this domain (26,28,29). In support of this theory, a stronger association to cognitive deficits for diminished expression than apathy has been shown in some studies of adult patients with schizophrenia, although the overall differences are not large, and not consistent regarding the cognitive domains involved (22,23,30). In the present study of adolescents with EOP, apathy and diminished expression were similarly associated with lower verbal learning performance.…”

“…Thus, we aimed to (1) explore the factorial structure of the negative symptom construct and (2) investigate associations between cognitive impairments and negative symptom domains in EOP. We hypothesized that two factors of negative symptoms will be identifiable; an apathy factor and a diminished expression factor, and that diminished expression is more strongly associated with cognitive impairments, in accordance with studies of adult patients [e.g., (22,23)].…”

“…This structure has been supported by a confirmatory factor analysis in an adult schizophrenia sample (19), and validated against corresponding subdomains of the Brief Negative Symptom Assessment Scale (20). Investigations of the two negative symptom domains, separately, have reported differential associations with other clinical aspects of psychotic disorders and neurobiology, including functional outcome (21), cognitive impairments (22,23), neuronal task activation (24), and white matter connectivity (25). Although the exact mechanisms still need to be elucidated, these results may indicate different underlying pathophysiology (26), which may require different treatment approaches.…”

“…More general cognitive impairments, according to the "cognitive resource limitation model", have been proposed to contribute to diminished expression symptoms (26,28,29). Some studies exploring the putative associations between cognition and the two negative symptom domains, have suggested a stronger association to cognitive impairments for diminished expression, than for apathy (22,23,30).…”

Pathophysiology of negative symptom dimensions of schizophrenia – Current developments and implications for treatment

“…A recent metaanalysis (n=309) has provided evidence for an improvement of overall negative symptoms (Cella et al, 2017a), but specific effects for apathy are unfortunately rarely reported. In this regard, post-hoc analyses based on data from a previously reported randomized 12week study with CRT in chronic patients (Lindenmayer et al, 2018) revealed that CRT improved severity of apathy measured with the Positive and Negative Symptoms Scale (PANSS) social amotivation factor (Sevy et al, 2020) (see (Fervaha et al, 2014;Liemburg et al, 2013) for more details on PANSS social amotivation factor). In relation to apathy, cognitive remediation interventions can potentially improve deficits of reward learning, which have been linked to deficits in cognitive functions, in particular, in working memory (Collins et al, 2017).…”