AgingUP: A Pilot Program to Reduce Self-Ageism and Self-Stigma in Older Adults With Severe Mental Illness

The goal of this pilot clinical trial is to learn whether AgingUP, a 10-session psychosocial program, helps reduce self-ageism and self-stigma and fosters more positive and realistic views of aging in older adults (≥50 years) living with severe mental illness. The main questions it aims to answer are: * Does participation in AgingUP reduce self-directed ageism compared to usual care? * Does it reduce internalized stigma related to mental illness? * Does it increase self-compassion? * Does it improve their perception of their own aging? Researchers will compare the AgingUP group with a control group receiving treatment as usual to see if participants in AgingUP show more adaptive perceptions of aging and self-concept. Participants will: * Attend 10 weekly group sessions (60-75 min each) focused on cognitive-behavioral techniques, acceptance and commitment strategies, self-compassion exercises, and empowerment (as a transversal element). * Complete brief questionnaires about their experiences and attitudes before and after the program.