This study extends previous literature by establishing the relationship of intrinsic motivation as a mediator between clinical status and functional outcomes among an ethnically/racially diverse sample of treatment-seeking individuals with schizophrenia spectrum disorders. Motivation was a statistically significant mediator of the relationship between functioning and global, positive, negative, and disorganized symptom scores. Further, with the exception of the positive symptom score, we found that the impact of psychiatric symptoms on functioning is fully mediated by intrinsic motivation. The results suggest that intrinsic motivation exerts strong influence on functional outcomes, largely beyond that of clinical status. While this is similar to findings from previous studies (Bellack, 2006
) which suggest that symptoms are not a strong determinant of functioning in community samples, we extend these findings by suggesting that the impact that symptoms might have on functioning is through their relationship with intrinsic motivation.
Our results suggest that intrinsic motivation may be part of the explanation for the relationship observed between clinical status and functional outcomes, yet much work is needed to determine the underlying mechanisms. A vast pool of interdisciplinary literature exists to inform the study of intrinsic motivation for schizophrenia. Possible approaches include: application of social psychological theories (Shah and Gardner, 2008
) that appear to fit well within the recovery framework for individuals with schizophrenia; review of clinical practice literature from within health and allied sciences, stretching back into the early 1970s (Lane and Barry, 1970
; Swanson and Woolson, 1973
); greater integration of basic science literature on motivation in the context of attitudes-behaviors into clinical practice (Fishbein, 1980
); examination of the potential generalizability of outcomes established with children with developmental disabilities (e.g., Lecavalier and Tassé, 2002
); and consideration of underlying neurocognitive and physiological components (e.g., Murray et al., 2008
; Nakagami et al., 2008
By examining ethnic minority status as a moderator in the mediation model we were able to approximate whether underlying sociocultural issues tied to ethnic/racial minority status might influence the findings. Differences in culture that influence self views were not assessed in this study, but have been found in a similar sample of individuals with schizophrenia (Brekke and Barrio, 1997
). For example, European Americans with independent, individualistic views of self tend to be internally motivated by self-interest and curiosity, while ethnic minorities in the United States tend to have higher interdependent self views and place great value on social relationships and external influences on their behavior (Gaines et al., 1997
; Markus and Kitayama, 1991
). If such a difference in self views exists in the current sample, it might help explain why persons in the ethnic minority group scored lower on intrinsic motivation than did individuals in the nonethnic minority group. The lack of moderation effect for ethnic minority status could reflect the sample characteristics; Latinos were likely to be well acculturated as they were proficient in English, able to use mental health services and to meet enrollment criteria for the research study.
Given the strong impact of intrinsic motivation on functioning, our findings suggest several treatment implications for individuals with schizophrenia. Drawing from social psychological research (Shah and Gardner, 2008
), we highlight possible ways that intrinsic motivation could be considered in designing theory based interventions for increasing functioning of individuals with schizophrenia. These approaches are designed to address functioning regardless of the level of most clinical symptoms. The presence of severe positive symptoms such as grandiosity may require additional interventions beyond the scope of our discussion.
Motivational interviewing (Miller and Rollick, 2002
) based on the Stages of Change theory (Prochaska and DiClemente, 1983
), has been recognized as one technique to facilitate goal setting and illness management required to increase functioning (Carey et al., 2001
). There is some empirical evidence of the effectiveness of motivational interviewing techniques for people with schizophrenia (Kemp et al., 1996
; Barrowclough et al., 2001
); these techniques have been effectively adapted as a part of best-practices for the treatment of people with dual diagnoses (Drake et al., 2001
; Ziedonis et al., 2005
). Intrinsic motivation can be embedded as an element of established interventions. Cognitive-training interventions to increase self-efficacy have been shown to be more effective when motivation is included as a primary focus (Medalia and Richardson, 2005
; Silverstein and Wilkniss, 2004
). Intrinsic motivation also can be considered as a core feature that can impact the process of delivering psychosocial interventions. Motivation is enhanced when the social context makes an individual feel autonomous and in control of his or her outcomes and when information is provided about the individual’s competence at navigating the social environment (Ryan and Deci, 2000
). Self-determination theory which suggests that competence, autonomy, and relatedness are necessary conditions to foster intrinsic motivation (Ryan and Deci, 2000
) could guide efforts to enhance these components embedded within the recovery model. The full extent of how to translate research findings on intrinsic motivation into clinical practice approaches to improve functional outcomes is an area in need of further study.
Several limitations warrant consideration in terms of interpreting our findings and also as indicators for future research directions. Our cross-sectional study design measured clinical status and functional outcomes prior to receipt of psychosocial rehabilitation services. Further research is needed to examine whether intrinsic motivation affects the rate or degree of change in symptoms and functioning throughout the course of treatment.
Our findings may not generalize to individuals with unstable or significant clinical symptoms or to persons of specific ethnic or racial subgroups as our sample size and composition precluded examination of a broad spectrum of these populations. While ethnic minority status provided one way to explore variation in intrinsic motivation, we were unable to directly test the effects of culture. Cultural values that may affect the extent to which intrapsychic processes, such as intrinsic motivation, are emphasized and drive behavior (Silverthorne, 2005
) could be tested. In addition, future studies should examine the mediation model among people with varying severity of symptoms or other clinical and sociocultural characteristics.
Our measure of intrinsic motivation was not specifically designed for this purpose. Development of an intrinsic motivation scale specific to individuals with severe and persistent mental illness, particularly for use in community-based services within complex ethnically diverse urban environments could improve the translation of these findings to practice (Barch et al., 2008
). Nonetheless, our use of a brief measure consisting of scores derived from open-ended interview probes permitted a personally elaborated view of intrinsic motivation and expanded the literature concerning individuals with schizophrenia.
We have much to learn about intrinsic motivation in the context of schizophrenia. While intrinsic motivation appears to be related to external reinforcers (Deci et al., 1999
), the optimal level or arrangement of motivation and reinforcers for sustaining functional outcomes is not known. Exploration of the additive effect and types of positive symptoms and their relationships to intrinsic motivation may be one avenue to pursue. Testing of various mediating or moderating variables would also contribute to our understanding of the influence of intrinsic motivation. Potential variables of interest include: clinical and sociodemographic characteristics or intrapsychic factors such as emotions, empowerment, self efficacy, autonomy, and illness insight (Bandura, 1991
; Gharabawi et al., 2007
; Herbener, 2008
; Ryan, 2007