Σείριος is a prevention and psychosocial health promotion organization serving residents across Thessaloniki’s five municipal districts through two local centers, covering the central and eastern sectors. Its work focuses on strengthening healthy attitudes, supporting people with everyday challenges, and encouraging effective communication and relationships. The organization provides information and prevention activities concerning substance-related and behavioral addictions, alongside counseling and support for individuals, families, and communities.

Its programs are designed for different stages of life and community settings. Services include groups for expectant mothers, parents, fathers, and grandparents, as well as activities for children and adolescents. For schools, Σείριος offers support for the school community, including educators and short-term classroom interventions. Community initiatives include creative activities, neighborhood talks to raise awareness, self-management and volunteering groups, and a smoking cessation group. The organization also maintains a library of books and articles and shares news and educational resources. Residents can contact either center for information about services and activities.