Among patients with mental diseases there is heterogeneity in terms of clinical response to psychopharmacological interventions, but relatively few studies are focused on the individual factors associated with better or poorer outcomes. The concept of biological age has been receiving an increasing amount of attention in mental health. Among the indicators of biological age, the Frailty Index (FI), which quantifies functional negative health attributes and measures their cumulative effect, has recently emerged in neuropsychiatric research as a reliable and comprehensive measure. Considering the above, and considering that the identification of predictors of treatment response is considered a key element of personalized medicine, the objective of the present study is to explore whether FI, a comprehensive measure of biological age and functional status, is a predictor of treatment outcome for patients with psychiatric diseases
