Chestnut Health Systems

Chestnut Health Systems is a psychiatrist and behavioral health provider in Belleville, IL, offering comprehensive services in mental health, substance use treatment, and primary care. The organization serves individuals across Illinois and Missouri, with a focus on coordinated, relationship-based care that integrates medical, behavioral, and social support. Specialized services include outpatient and inpatient substance use treatment, mental health care and housing, primary medical and dental services, and medication-assisted recovery programs. It operates through a network of clinics and community-based initiatives, including school-based services and mobile crisis response across 13 southwestern Illinois counties.

Chestnut Health Systems is a private, not-for-profit 501(c)(3) organization governed by a volunteer Board of Directors. It has maintained continuous accreditation by The Joint Commission since 1975 and operates under a mission to improve quality of life through excellence in service. The organization provides care across four core service areas: mental health treatment and housing, primary care and preventative services, substance use treatment and prevention, and applied behavioral research, training, and publications. It supports individuals through a range of programs, including crisis response, recovery services, and community partnerships, with an emphasis on accessible, high-quality care for underserved populations.

Chestnut Health Systems is known for a steady record of repeat and referred customers, reflecting sustained trust in its services. The organization emphasizes whole-person care, connecting individuals to medical, mental health, and social resources through a coordinated approach. Its work is informed by research, community engagement, and ongoing innovation, as demonstrated through its podcast and newsletter, The Catalyst, which shares insights on public health, policy, and care delivery. The organization continues to expand access to behavioral health services, particularly in rural and underserved areas of southwestern Illinois.