Assessing Individual Differences in the Affective Experience of Dreams: The Jena Dream Inventory-Affect Scales (JeDI-A).

The study reports on the validation of a new instrument for the assessment of emotional experiences in dreams. The Jena Dream Inventory-Affect (JeDI-A) contains 21 items and 3 scales, positive dream affect, negative dream affect, and dream intensity, providing a differentiated yet economic assessment of dream affect. Cross-sectional and longitudinal analyses in a sample of university students (N = 426) and a clinical sample of patients with sleep disorders (N = 149) supported factorial validity and measurement invariance, high temporal stability (over 1 year and 9 months in the students and patients, respectively), convergent and discriminant validity regarding established measures of dream affect and the Big Five, and criterion validity regarding subjective well-being. Cross-lagged panel models showed reciprocal longitudinal effects between dream affect and waking affect. We conclude that the JeDI-A is a valid instrument for differentiated investigations of individual differences in dream affect in clinical and nonclinical populations.