Innovations In Clinical Neuroscience

NOV-DEC 2017

A peer-reviewed, evidence-based journal for clinicians in the field of neuroscience

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19 ICNS INNOVATIONS IN CLINICAL NEUROSCIENCE November-December 2017 • Volume 14 • Number 11–12 O R I G I N A L R E S E A R C H (SANS) 6 defined negative symptoms, and 30 years after the Positive and Negative Syndrome Scale (PANSS) 7 identified a negative symptom subscale and yielded multiple factor structures, uncertainties about the symptoms that comprise the negative symptom dimension and their optimal assessment 8-9 still exist. Recent research has suggested that negative symptoms can be considered in terms of two different dimensions: diminished expression (expressive deficit) and reduced experience (experiential deficit). 10–13 Expression includes displays of facial affect (referred to as blunted affect), reduced vocal inflection, and reduced vocal output. Experience includes the motivation to engage in potentially pleasurable activities and the subjective experience of enjoyment when engaging in reinforcing activities. This second dimension has also been referred to as reflecting avolition and apathy, as a descriptor of the observable consequences of deficits in experience. These two domains have been reported to be quite separable, with factor analyses suggesting that experience and expression are separate factors. 14 Importantly, different clusters of patients can be identified whose primary presentations reflect diminished expression, reduced experience, or low levels of negative symptoms. 15 Thus, these domains of negative symptoms appear quite robust and disinct. Studies examining the prediction of functional outcomes in schizophrenia have suggested that social functioning, everyday activities, and vocational and other productive outcomes might have different determinants. Specifically, deficits in cognition and functional capacity appear to predict residential and vocational outcomes better than social outcomes. 16 Cross-sectionally, negative symptoms appear to be more strongly related with social outcomes, with additional contributions from social cognition and social competence. 17 However, some of the research on domains of negative symptoms has suggested that reduced experience (i.e., avolition-asociality) has a more potent impact on social outcomes than reduced expression. 18 Thus, studies in which overall scores on negative symptoms are found to predict social outcomes might not capture the specifics of prediction as precisely as possible. In fact, in our research, overall scores on negative symptoms accounted for less variance in social outcomes than did two of the symptoms on the PANSS typically seen to reflect reduced experience: active and passive social avoidance. We present the results of a study using PANSS-derived factors reflecting reduced expression and experience from the study of Khan et al. 19a We took these factors and then used them to predict three different aspects of functional outcome in a dataset on which we had previously published. 16 Our primary aim is to assess the relative prediction potential of PANSS expression deficits and PANSS experience deficits in comparison with each other and as compared with the combined negative symptom factor (PANSS NSF) for the prediction of social, vocational, and everyday activities in a large and well-assessed sample of people with schizophrenia. In that previous study, 16 the best fitting predictor model was that overall negative symptoms predicted social outcomes, but not vocational or residential outcomes, and that cognition and functional capacity predicted vocational and residential outcomes, but not social functioning. METHODS The sample of patients and their assessments was previously reported by Strassnig et al. 16 We will review the details of the previous study briefly. Participants. The data are part of four study cohorts collected in five different geographical areas within the United States, aimed at identifying the course and correlates of change in functional status as well as the optimal method for rating everyday functioning among schizophrenia outpatients. The study participants were patients (n=821) with schizophrenia or schizoaffective disorder receiving treatment at one of several different outpatient service delivery systems in Atlanta, Dallas, Miami, San Diego, and the city of New York. All research participants provided signed informed consent per standards approved by the responsible local Institutional Review Boards. These data were collected between March 2003 and May 2014. All enrollees completed a structured diagnostic interview, administered by a trained interviewer. The Structured Clinical Interview for the DSM (SCID19) was used at the Atlanta sites, the Mini International Neuropsychiatric Interview, 6th Edition 20 was used in Dallas, San Diego, and Miami, and the Comprehensive Assessment of Symptoms and History (CASH 21 ) was used in New York; all diagnoses were verified in local consensus procedures. Patients were excluded if they had a history of traumatic brain injury, brain disease such as seizure disorder or neurodegenerative condition, a reading score below the sixth grade in all samples, or the presence of another Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) diagnosis that would exclude the diagnosis of schizophrenia. These procedures were described in previous publications. 1,22–24 Assessment strategy. Real world functioning. Real world functioning was rated with the SLOF 25 across all study cohorts. Across the studies, ratings were generated by a high-contact clinician, either a case manager, a residential facility manager, or a psychotherapist who stated that they knew patient "very well." The original SLOF was abbreviated to assess five functional domains from which we selected the following domains to be examined in all studies: interpersonal functioning (e.g., initiating, accepting, and maintaining social contacts; effectively communicating), independent participation in everyday activities (e.g., shopping, using TABLE 1. Descriptive statistics on the outcomes and predictor variables OUTCOMES MEAN STANDARD DEVIATION SLOF Interpersonal functioning 25.87 6.59 SLOF everyday activities 45.93 9.38 SLOF vocational functioning 22.83 5.54 Cognitive composite 36.84 7.62 UPSA-B total score 71.85 16.72 Negative symptoms total score 14.24 5.73 SLOF: specific levels of functioning; UPSA-B: University of California, San Diego Performance-based Skills Assessment- brief

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