Sexual Desire and Erotic Fantasies Questionnaire: Validation of the Erotic Fantasy Inventory Scale (SDEF3) in Italian Adults

Background: Erotic fantasies are the most common sexual experiences and provide valuable clinical material for understanding individual and relational emotional dynamics. The primary objective of this study is to validate the Sexual Desire and Erotic Fantasies questionnaire (SDEF) Part 3–Inventory of Erotic Fantasies. This questionnaire was designed to be a sex-positive and inclusive measure of the content of erotic fantasies, accessible to individuals of all gender identities, sexual orientations, relationship/romantic status, and sexual behaviors. Methods: The SDEF3 was completed by 1773 Italian participants (1105 women, 645 men, and 23 participants identifying as other genders). Two factorial structures were presented and discussed: a 20-dimension structure for clinical and explorative use and a 6-dimension structure for research purposes. Results: The six-factor version was preferred due to its robust statistical properties and its ability to differentiate between sexually clinical and functional men and women, based on cut-off scores from the Female Sexual Function Index (FSFI) and the International Index of Erectile Function (IIEF). Differences in the frequency of themes in fantasies between gender and sexual orientation were reported and discussed. Conclusions: The current study indicates that the SDEF3 is a valuable and comprehensive measure for assessing various scenarios related to fantasizing activity. It has potential applications in both clinical practice and scientific research.