Impaired ability to imagine future pleasant events is associated with apathy in schizophrenia

摘要

Recent research has established that schizophrenia patients have difficulties envisioning the future. Although mental simulations have a clear adaptive value, little is known about the function of simulating future episodes, particularly emotional events. The aim of this study was to explore the relationships between apathy and future projection in schizophrenia. Twenty-five schizophrenia patients and 25 healthy controls were asked to imagine pleasant and unpleasant episodes that might happen to them in the future. Verbal descriptions were scored for specificity, and participants also completed the Memory Characteristics Questionnaire, which assesses phenomenal characteristics of imagined future events. Apathy was assessed with the Lille Apathy Rating Scale and the apathetic/social withdrawal item of the Positive and Negative Syndrome Scale. Results showed that schizophrenia patients' pleasant and unpleasant imagined future events were less specific and contained fewer phenomenal characteristics (e.g., amount of sensory details) than those of controls. In the schizophrenia group, difficulties imagining future pleasant events, and particularly poor self-referential information for future pleasant events, were specifically associated with apathy, even after controlling for working memory. These results suggest that episodic future thinking impairments, especially for future events of pleasure, may partly underlie the motivational deficits characteristic of schizophrenia.