Avolition in schizophrenia is associated with reduced willingness to expend effort for reward on a Progressive Ratio task

Abstract

The current study examined whether effort-cost computation was associated with negative symptoms of schizophrenia (SZ). Participants included outpatients diagnosed with SZ (n=27) and demographically matched healthy controls (n=32) who completed a Progressive Ratio task that required incrementally greater amounts of physical effort to obtain monetary reward. Breakpoint, the point at which participants was no longer willing to exert effort for a certain reward value, was examined as an index of effort-cost computation. There were no group differences in breakpoint for low, medium, or high value rewards on the Progressive Ratio task. However, lower breakpoint scores were associated with greater severity of avolition and anhedonia symptoms in SZ patients. Findings provide further evidence that impaired effort-cost computation is linked to motivational abnormalities in SZ.