Lessons learned from the New York State mental health response to the September 11, 2001, attacks.

OBJECTIVE In the aftermath of the September 11, 2001, attacks on the World Trade Center, the public mental health system in New York City mounted the largest mental health disaster response in history, called Project Liberty. The successes and challenges of Project Liberty are evaluated. METHODS The development of Project Liberty is summarized and analyzed from the perspective of the New York State and New York City officials and scientists who led the disaster response. Lessons learned that have implications for mental health support in future disaster responses are offered. RESULTS A high level of interagency collaboration, engagement of nongovernmental organizations to provide services, media education efforts, and ongoing program evaluation all contributed to the program's successes. Mental health professionals' limited experiences with trauma, options for funding treatment, duration of clinical program, and existing needs assessments methodologies all proved challenging. CONCLUSIONS Project Liberty was a massive and invaluable resource during the years of rebuilding in New York City in the wake of the attacks. Challenges faced have led to lessons of generalizable import for other mental health responses to large-scale events.