PHENOMENOLOGICAL DIFFERENCES BETWEEN HISPANIC AND CAUCASIAN SCHIZOPHRENIA SUBJECTS

Abstract

prised of two key symptom subdomains: 1) diminished expression (affective flattening and poverty of speech); and 2) amotivation (apathy and anhedonia), and contribute to functional impairment in this illness. Recent data, including our own work, suggests that motivational deficits serve as a critical determinant to functioning. This study aims to explore the longitudinal relationship between motivational and pleasure deficits, cognitive dysfunction, and functional outcomes in schizophrenia. We hypothesize that motivational deficits are the critical determinant of both current and future functioning in individuals with schizophrenia. Methods: Outpatients between the ages of 18 and 55with a diagnosis of schizophrenia, on stable doses of antipsychotic medication, were evaluated at baseline and 6 months later with the Scales for the Assessment of Positive Symptoms (SAPS) and Negative Symptoms (SANS). Amotivationwas assessed with the Apathy Evaluation Scale – Clinician version (AES-C), anticipatory/consummatory pleasure with the Temporal Experience of Pleasure Scale (TEPS), and cognition with theBriefAssessmentofCognition inSchizophrenia (BACS). TheQuality of Life Scale (QLS) was used to evaluate functional status. Results: Nineteen participants (mean age of 42 years, mean duration of illness of 15 years) were assessed at both baseline and 6 months. Stepwise hierarchical regression revealed that baseline amotivation, as measured by the AES-C, was the strongest predictor of both baseline and future functioning, as measured by the QLS. Specifically, AES-C scores accounted for 75% of the variance in baseline functioning (R2 change=0.749, p<.001), and 73% of the variance in functioning at 6month follow-up (R2 change=0.727, p<.001). After exclusion of the Intrapsychic Foundations subscale of the QLS due to overlap in item content with amotivation measures, the AES-C score continued to be the strongest predictor of functioning at baseline and follow-up, accounting for 65% and64%of the variance in functioning, respectively. Positive symptoms (SAPS total score) explained an additional 7% and 5% of the variance in functioning at baseline and follow-up, respectively. Further, amotivation measured by the SANS amotivation subdomain explained an additional 8% and 10% of the variance in functioning at baseline and follow-up, respectively. Other measures including TEPS anticipatory/consummatory pleasure scores, and BACS composite score did not offer additional predictive value. Discussion: Negative symptoms have been implicated in poor functional outcome, with recent work suggesting that motivational deficits are the central link between negative symptoms and poor functioning. The present data take this issue a step further and examine the longitudinal relationship between the negative symptoms of schizophrenia and functional outcomes. In keeping with the cross-sectional findings, motivational deficits appear to play a pivotal role in predicting longitudinal functional outcomes in schizophrenia, with other symptom domains offering little, if any, additional contribution. These preliminary findings highlight the importance of motivational deficits in schizophrenia, and suggest that it is this loss of drive that links negative symptoms to poor functional outcomes.