Negative symptoms such as reductions in motivation and goal-oriented behavior have long been considered a key feature of psychotic disorders (e.g., bipolar disorder, schizophrenia, schizoaffective disorder). These symptoms are detrimental to social and occupational functioning because decreases in motivation may impair work productivity and social relationships. However, treatments for psychotic disorders (e.g., antipsychotic medications) have proven largely ineffective at reducing negative symptom severity in psychotic patients, in part due to poor understanding of the mechanisms that give rise to these symptoms. The current project aims to examine one potential mechanism, which might contribute to motivational impairment in psychotic disorders, aberrant effort allocation. More specifically, patients with psychotic disorders may overestimate the ?cost? of the effort necessary to pursue goals, and due to this elevated ?cost? may fail to initiate actions to obtain goals. Supporting this hypothesis, research shows that patients with psychosis (schizophrenia and schizoaffective) are less motivated than controls to exert both physical and cognitive effort to obtain rewards on experimental tasks, and that this task deficit is related to negative symptoms. However, despite strong behavioral evidence for abnormal effort-cost computation in psychotic disorders, studies have not examined the neural correlates of this deficit. Such studies may ultimately inform novel biological targets for future interventions by linking biological mechanisms to emerging basic science frameworks that have delineated the biological pathways that give rise to effortful choice. The current proposal addresses this ?gap? in the literature by examining the neural correlates of effort-based decision-making in psychosis (schizophrenia and schizoaffective) using fMRI and a well-validated effort-based decision-making paradigm. Further, the current proposal aims to directly examine the relationship between aberrant effort-based decision-making and daily emotional experience. Specifically, we propose to examine daily levels of self-reported motivation as subjects go about there daily lives and quantify whether these measures relate to effort-based decision-making measured in the lab. This approach of relating experimental findings to real-world function is rare in the literature. Thus, this proposal fills a much-needed ?gap? between our mechanistic understanding of effort-based decision-making and the impact of such dysfunction on the daily lives of those with and without psychopathology. The long-term objectives of this project contribute to public health by examining a potential contributory mechanism for a widely distressing and poorly treated aspect of psychotic disorders. Ultimately, such findings may inform novel biological targets for future interventions and preventive approaches.
Treatments for psychotic disorders (e.g., antipsychotic medications) have proven largely ineffective at reducing motivational deficits in psychotic patients, in part due to poor understanding of the mechanisms that give rise to these symptoms. The current project aims to better understand a potential mechanism, cognitive effort avoidance, which might give rise to such deficits and to relate this mechanism to daily emotional experience and behavior in those with psychotic disorders and healthy individuals. Identifying such mechanisms and their contributions to daily emotional experience may assist in identifying treatment targets for novel interventions and preventive approaches aimed at improving the lives of those with psychosis.
| Culbreth, Adam J; Moran, Erin K; Barch, Deanna M (2018) Effort-Based Decision-Making in Schizophrenia. Curr Opin Behav Sci 22:1-6 |
