Measuring Vitality and Depletion During Adolescence: Validation of the Subjective Vitality/Subjective Depletion Scale in a Sample of Italian Students

<b>Background/Objectives</b>: Adolescence is a critical developmental phase marked by rapid cognitive, emotional, and social changes that influence how individuals experience psychological energy and exhaustion. Self-Determination Theory recently proposed a dual-process model, based on two distinct, yet related, constructs: Subjective Vitality, associated with well-being and positive health outcomes, and Subjective Depletion, associated with illbeing and negative emotions. Since, to date, no study has investigated vitality and depletion during adolescence, this study aims to validate the Subjective Vitality/Depletion Scale (SVDS) in a large sample of adolescents. <b>Methods</b>: A total of 1111 Italian adolescents (Mage = 14.49, SDage = 1.49; 48% females) completed the SVDS and other validated self-report measures. Specifically, the psychometric properties of the SVDS across biological sex and age groups and latent mean differences across these groups were assessed. <b>Results</b>: Findings supported the dimensionality of the SVDS with two correlated factors, and its construct validity through associations with positive and negative affect and basic psychological needs satisfaction. Full invariance for the SVDS was achieved across biological sex and age groups. Latent mean analyses indicated that males reported higher levels of vitality compared to females (Cohen's d = 0.46), with no significant differences for depletion; older adolescents reported lower levels of vitality (d = -0.23) and higher levels of depletion (d = 0.20) compared to younger adolescents. <b>Conclusions</b>: These findings support the SVDS as a valid and reliable instrument for assessing energy-related experiences in adolescence. The results suggest meaningful sex differences and a potential developmental trend of declining subjective energy from early to later adolescence.