title: The reward probability index: design and validation of a scale measuring access to environmental reward.
abstract: Behavioral models of depression implicate decreased response-contingent positive reinforcement (RCPR) as critical toward the development and maintenance of depression (Lewinsohn, 1974). Given the absence of a psychometrically sound self-report measure of RCPR, the Reward Probability Index (RPI) was developed to measure access to environmental reward and to approximate actual RCPR. In Study 1 (n=269), exploratory factor analysis supported a 20-item two-factor model (Reward Probability, Environmental Suppressors) with strong internal consistency (α=.90). In Study 2 (n=281), confirmatory factor analysis supported this two-factor structure and convergent validity was established through strong correlations between the RPI and measures of activity, avoidance, reinforcement, and depression (r=.65 to .81). Discriminant validity was supported via smaller correlations between the RPI and measures of social support and somatic anxiety (r=-.29 to -.40). Two-week test-retest reliability was strong (r=.69). In Study 3 (n=33), controlling for depression symptoms, hierarchical regression supported the incremental validity of the RPI in predicting daily diary reports of environmental reward. The RPI represents a parsimonious, reliable, and valid measure that may facilitate understanding of the etiology of depression and its relationship to overt behaviors.
authors.affiliation: University of Tennessee-Knoxville, Knoxville, TN 37996, USA.
authors.forename: John P
authors.initials: JP
authors.lastname: Carvalho
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Gawrysiak
authors.forename: Julianne C
authors.initials: JC
authors.lastname: Hellmuth
authors.forename: James K
authors.initials: JK
authors.lastname: McNulty
authors.forename: Jessica F
authors.initials: JF
authors.lastname: Magidson
authors.forename: C W
authors.initials: CW
authors.lastname: Lejuez
authors.forename: Derek R
authors.initials: DR
authors.lastname: Hopko
mesh_terms: D000293:Adolescent; D001007:Anxiety / Q000523:psychology*; D003863:Depression / Q000523:psychology*; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008960:Models, Psychological; D011594:Psychometrics; D015203:Reproducibility of Results; D012201:Reward; D012944:Social Support; D011795:Surveys and Questionnaires; D055815:Young Adult