Executive dysfunctions differentially predict amotivation in first-episode schizophrenia-spectrum disorder: a prospective 1-year follow-up study

Abstract

Amotivation is a major determinant of functional outcome in schizophrenia but it is understudied in the early course of illness. There is a paucity of longitudinal research investigating predictors of amotivation. In this study, we aimed to examine baseline cognitive and clinical predictors of amotivation at 6 and 12 months of follow-up in patients aged 18–55 years presenting with first-episode DSM-IV schizophrenia-spectrum disorder (FES). Of 145 patients recruited at intake, 116 and 113 completed assessments at 6- and 12-month follow-up, respectively. Amotivation was measured by avolition-apathy and anhedonia-asociality subscale scores of the Scale of the Assessment of Negative Symptoms. Cognitive assessment was administered at baseline. As executive dysfunction has been more consistently found to be associated with negative symptoms and amotivation in prior literature, we adopted fractionated approach to subdivide executive function into distinct components encompassing switching and flexibility, response initiation, response inhibition, planning and strategy allocation, sustained attention and working memory. Our results showed that baseline amotivation (p = 0.01) and switching and flexibility (p = 0.01) were found to independently predict amotivation at 6 months follow-up. Baseline amotivation (p < 0.01) and switching and flexibility (albeit with trend-wise significance, p = 0.06) were also retained in final multivariate regression model for 12-month amotivation prediction. No other executive components or cognitive domains predicted amotivation at follow-up. Findings of our study thus indicate amotivation at initial presentation as a critical determinant of subsequent motivational deficits over 1 year of treatment for FES patients. Cognitive flexibility might be specifically related to the development of amotivation in the early stage of illness.