Validation and Psychometric Properties of the French Versions of the Environmental Reward Observation Scale and of the Reward Probability Index

Background: Low levels of environmental rewards have been related to depression on a number of occasions in the scientific literature. Two scales have been created to assess environmental rewards: the Environmental Reward Observation Scale (EROS) and the Reward Probability Index (RPI). This study aims to validate the French versions of these two scales. Method: 466 non-clinical adults completed an online survey assessing environmental rewards, depression, anxiety, activation, avoidance and behavioural systems. Confirmatory factor analyses were performed to assess the factorial structures of the French EROS and RPI. Results: A one-factor solution for the EROS and a two-factor solution for the RPI best fitted the data. High levels of internal consistency were found for both the EROS and the RPI. Convergent validity was also examined, revealing that high environmental rewards appear to be related to activation and behavioural activation system. Conclusion: The French versions of the EROS and the RPI appear to be reliable assessments of environmental rewards.