Trauma-Informed Care: What Do We Know?

Trauma-informed care is recognized as an important approach to serve trauma survivors who are experiencing homelessness. But what does the research say about the effectiveness of trauma-informed care? This article offers a summary of research findings related to trauma-informed care.

Research shows that people who are homeless have experienced high rates of trauma. Many who enter the homeless services system have experienced violence, loss, and disruptions to important relationships from an early age. The experience of homelessness is also very traumatic. People without a home experience the loss of place, safety, stability, and community. The experience of violence and other traumatic events can be shattering. Their impact permeates all levels of relational development by calling trust into question. What was once assumed safe is no longer that way.

This is the experience of many of the people who walk in the door to seek assistance from a homeless service agency. Trauma-informed care includes understanding trauma and its effects, creating safe physical and emotional space, supporting consumer choice and control, and integrating trauma-informed care across service systems. When a person feels safe, they are better able to move toward recovery.

To be a “trauma-informed” provider is to root your care in an understanding of the impact of trauma and the specific needs of trauma survivors. To learn more about what it means to be a trauma-informed provider, read “Trauma-Informed Care 101.”

What does the research say about trauma-informed care? A review of the research literature shows that trauma-informed care has promising results on a number of different counts:

  • Trauma-informed service settings have better outcomes than “treatment as usual.” A variety of studies have revealed that programs utilizing a trauma-informed model are associated with a decrease in psychiatric symptoms and substance use. Some programs have shown an improvement in daily functioning and a decrease in trauma symptoms, substance use, and mental health symptoms (Cocozza et al., 2005; Morrissey and Ellis, 2005; Kammerer et al., n.d.).
  • Trauma-informed services for children lead to better self-esteem, improved relationships, and increased safety. Programs that examined the impact of a trauma-informed intervention for children found that one year later, children demonstrated a more positive self-identity, increased tools for building healthy relationships, and improved safety. (Finkelstein et al., 2005; Noether et al., 2007).
  • Trauma-informed services may have a positive effect on housing stability. A multi-site study of trauma-informed services for homeless families found that almost 90% of participants had either remained in Section 8 housing or moved to permanent housing (Rog, Holupka, and McCombs-Thornton, 1995).
  • Trauma-informed services may lead to decreased utilization of crisis-based services. Some studies have found decreases in the use of intensive services such as hospitalization and crisis intervention following the implementation of trauma-informed services (Community Connections, 2002).
  • Trauma-informed, integrated services are cost-effective. Trauma-informed integrated services show improved outcomes, but generally do not cost more than standard programming (Domino et al., 2005).
  • Providers report positive outcomes in their organizations from implementing trauma-informed services. Providers reported greater collaboration with consumers, enhanced skills, and a greater sense of self-efficacy among consumers. Supervisors reported more collaboration within and outside their agencies, improved staff morale, fewer negative events, and more effective services (Community Connections, 2002).
  • Consumers respond well to trauma-informed services. Survey results have found that consumers report an increased sense of safety, better collaboration with staff, and a more significant “voice.” (Jennings, 2004).

Despite all that we do know about the positive impact of trauma-informed care, there still remain significant questions to be answered:

  • Are outcomes a result of trauma-informed environments, trauma-specific interventions, or both? Because most trauma-informed service settings also include trauma-specific interventions, the extent to which each component contributes to change is difficult for research studies to determine.
  • Are trauma-informed services effective specifically within homelessness settings? Although research in other fields suggests that trauma-informed services may be effective for homeless individuals, there have yet to be any rigorous, quantitative studies exploring outcomes within homelessness service settings.

To request FREE HRC Trauma-Informed Care training for your agency, contact Laura Winn. For more information on trauma and its impact, visit the HRC Trauma topic page.


Cocozza, J.J., Jackson, E.W., Hennigan, K., Morrissey, J.B., Reed, B.G., & Fallot, R. (2005). Outcomes for women with co-occurring disorders and trauma: Program-level effects. Journal of Substance Abuse Treatment, 28(2), 109-119.

Community Connections. (2002). Trauma and Abuse in the Lives of Homeless Men and Women. Online PowerPoint presentation. Washington, DC: Authors. Retrieved September 3, 2007, from

Domino, M. E., Morrissey, J. P., Chung, S., Huntington, N., Larson, M. J., & Russell, L.A. (2005). Service use and costs for women with co-occurring mental and substance use disorders and a history of violence. Psychiatric Services, 56, 1223-1232.

Finkelstein, N., Rechberger, E., Russell, L.A., VanDeMark, N.R., Noether, C.D., O’Keefe, M., et al. (2005). Building resilience in children of mothers who have co-occurring disorders and histories of violence: intervention model and implementation issues. Journal of Behavioral Health Services Research, 32(2), 141-154.

Jennings, A. (2004b). Models for Developing Trauma-Informed Behavioral Health Systems and Trauma-Specific Services. Alexandria, VA: National Association of State Mental Health Program Directors, National Technical Assistance Center for State Mental Health Planning. Retrieved September 3, 2007, from

Kammerer, N. et al. (n.d.). Project RISE Evaluation Report. Boston, MA: Health and Addictions Research, Inc., and Institute for Health and Recovery. Unpublished program evaluation report.

Morrissey, J.P., and Ellis, A.R. (2005). Outcomes for women with co-occurring disorders and trauma: Program and person-level effects. Journal of Substance Abuse Treatment, 28(2), 121-133.

Noether, C.D., Brown, V., Finkelstein, N., Russell, L.A., VanDeMark, N.R., Morris, L.S. et al. (2007). Promoting resiliency in children of mothers with co-occurring disorders and histories of trauma: Impact of a skills-based intervention program on child outcomes. Journal of Community Psychology, 35(7), 823-843.

Rog, D., Holupka, S., and McCombs-Thornton, K. (1995a). Implementation of the Homeless. Families Program: 1. Service models and preliminary outcomes. American Journal of Orthopsychiatry, 65(4), 502-513.

Publication Date: 
Rockville, MD, USA