The pleasure expectancies scale (PLEX): A brief measure of expectancies for pleasure in schizophrenia

A critical dysfunctional belief system implicated within the cognitive model of negative symptoms is low expectancies for pleasure, which refers to unhelpful beliefs characterized by generally negative expectations for one's likelihood of experiencing pleasure. In light of concerns regarding existing measures of anticipatory pleasure, the current study sought to examine the reliability and validity of a new brief self-report questionnaire, titled the Pleasure Expectancies Scale (PLEX). One hundred twenty five individuals with a diagnosis of schizophrenia-spectrum disorder (SSD) were administered the 8-item PLEX, along with a battery of other clinical and cognitive measures. The psychometric properties of the PLEX were evaluated. Cronbach's alpha was acceptable at baseline (α = 0.741) and good at the 6-month follow-up (α = 0.815, n = 75). Correlational analyses demonstrated good convergent and discriminant validity, as well as test-retest reliability at 6 months. Construct validity, as it pertains to the cognitive model of negative symptoms, was also established by way of significant correlations with negative symptoms, diminished motivation, and defeatist performance beliefs. Hierarchical regressions also revealed that the PLEX accounted for greater variance in negative symptoms beyond that of existing measures of anticipatory pleasure. Our findings suggest that the PLEX is a promising new measure of expectancies for pleasure in individuals with SSDs, with good indicators of reliability and validity. The PLEX lends itself well to both research and clinical settings, which may be particularly important given the hypothesized role of dysfunctional beliefs as mechanistic targets for treating negative symptoms using psychosocial interventions.