To address significant gaps in our understanding about how neurocognition, intrinsic motivation (IM), and psychosocial functioning are interrelated in schizophrenia, this study investigated the following questions: Is IM stable or dynamic over time? Does neurocognition predict change in IM over time? What is the association between change in neurocognition, change in IM, and change in psychosocial functioning? Finally, what is the causal structure of the relationships among neurocognition, IM, and psychosocial functioning over time? One hundred and thirty individuals diagnosed with schizophrenia or schizoaffective disorder were recruited from 4 community-based psychosocial rehabilitation programs in urban Los Angeles. Measures of neurocognition were taken at baseline and 12 months. Measures of IM, psychosocial functioning, and symptoms were taken at baseline, 6, and 12 months. Results of latent growth curve modeling analyses demonstrated that IM is dynamic over time. Baseline neurocognition was associated with the initial level of IM but did not predict the rate of change in motivation. However, baseline levels of IM predicted rates of subsequent improvement in neurocognition. Change in IM was strongly associated with change in psychosocial functioning, and change in neurocognition was associated with change in psychosocial functioning, but change in IM was not associated with change in neurocognition. Latent difference score analyses revealed that neurocognition caused changes in psychosocial functioning, and psychosocial functioning caused changes in IM. These findings improve our fundamental understanding of the relationships among these variables and contribute to intervention development for improving outcomes in schizophrenia.Key words: intrinsic motivation/neurocognition/ schizophrenia/psychosocial functioning/outcome/ rehabilitation
IntroductionRecent studies indicate that neurocognition and intrinsic motivation (IM) have significant functional consequences for individuals with schizophrenia.1-8 Substantial research links aspects of neurocognition to functional outcomes in work, social, and independent living domains (for review, see Green et al ) and functional improvement during rehabilitation. 2,4,5 There is newer but also growing literature linking intrinsic and extrinsic motivation separately to functional outcomes and treatment responsiveness (eg, Choi and Medalia
6). There is also recent evidence that IM mediates the relationship between neurocognition and functional outcomes. 7,8 While knowledge is growing in this area, we lack a fundamental understanding of how these variables are interrelated. A prospective approach is essential to better understand the relationships among neurocognition, IM, and functional outcomes in schizophrenia. Longitudinal multiwave data will allow for an examination of the relationships among change in these variables over time as well as for modeling the causal relationships among them. This will contribute to understanding the relationships among these variables, as w...