Below are two examples of key studies which explored the connections between between trauma, substance use and mental health.

Example 1 - The Adverse Childhood Experiences Study (ACE)

The ACE study looked at the life histories of 17,337 people in the U.S. to determine the connections between adverse childhood experiences and health in adulthood. A number of research articles were published that corroborate the link between adverse childhood experiences and health outcomes including substance use, mental health issues and violence. The study produced an assessment tool called the ACE Score, which is used to identify health risks based on the number of positive responses.

• Anda, R. F., Felitti, V. J., Bremner, J. D., Walker, J. D., Whitfield, C., Perry, B. D., et al. (2006).
  The enduring effects of abuse and related adverse experiences in childhood. European Archives of Psychiatry & Clinical Neuroscience, 256(3), 174-186.
  
  Detailing the methods and results of the ACE study, this article includes information on the effects of adverse experiences on the brain.
  Link to Abstract »
• Chapman, D., Whitfield, C., Felitti, V., Dube, S., Edwards, V., & Anda, R. (2004).
  Adverse childhood experiences and the risk of depressive disorders in adulthood. Journal of Affective Disorders, 82(2), 217-225.
  
  The authors discuss the degree to which the number of adverse childhood events is associated with increased depression in adulthood.
  Link to Abstract »
  
• Dube, S., Felitti, V., Dong, M., Chapman, D., Giles, W., & Anda, R. (2003).
  Childhood abuse, neglect, and household dysfunction and the risk of illicit drug use: The adverse child experiences study. Pediatrics, 111(3), 564-572.
  
  Ten categories of adverse childhood events were measured. For people reporting five or more  adverse events, the likelihood of illicit drug use increased 7- to 10-fold. Other risk factors are discussed.
  Link to Abstract »
  

Example 2 - The Women, Co-occurring Disorders and Violence Study (WCDVS)

The WCDVS, funded by the US Substance Abuse and Mental Health Services Administration, was a groundbreaking study designed to pilot interventions  that addressed the needs of women with substance use and mental health concerns  and histories of trauma and violence. Results from the WCDV study provided promising evidence that trauma-informed, comprehensive services were needed to provide better care to women with these co-occurring problems. In the final phase of the study 2,729 women were enrolled in 9 sites across the U.S. Half were enrolled into traditional service models and half into integrated services. There are many articles published about this study’s findings. The following articles were selected for their focus on the connections of trauma, mental health and substance use among women.

• Amaro, H., Larson, M. J., Gampel, J., Richardson, E., Savage, A., & Wagler, D. (2005).
  Racial/Ethnic differences in social vulnerability among women with co-occurring mental health and substance abuse disorders: Implications for treatment services. Journal of Community Psychology. Special issue: Serving the Needs of Women With Co-Occurring Disorders and a History of Trauma, 33(4), 495-511.
  
  Women with co-occurring disorders and a history of violence have significant and special needs that are not being met with existing services
  Link to Wiley Abstract »
• Becker, M. A., Noether, C. D., Larson, M. J., Gatz, M., Brown, V., Heckman, J. P., et al. (2005).
  Characteristics of women engaged in treatment for trauma and co-occurring disorders: Findings from a national multisite study. Journal of Community Psychology. Special issue: Serving the Needs of Women With Co-Occurring Disorders and a History of Trauma, 33(4), 429-443.
  
  This study demonstrated that women in treatment for trauma and co-occurring disorders have  substantial mental and physical health needs and a significant history of violence and abuse.
  Link to Wiley Abstract »
• Gatz, M. R., Lisa A.; Grady, Janice; Kram-Fernandez, Debra; Clark, Colleen; Marshall, Brenda,. (2005).
  Women's recollections of victimization, psychological problems, and substance use. Journal of Community Psychology. Special issue: Serving the Needs of Women With Co-Occurring Disorders and a History of Trauma., 33(4), 479-493.
  
  Data from this study demonstrated that 2/3 of women who had experienced physical and sexual abuse reported that it occurred before they were 18 years old. The study also found that the abuse preceded substance use disorders.
  Link to Wiley Abstract »
• Larson, M. J., Miller, L., Becker, M., Richardson, E., Kammerer, N., Thom, J., et al. (2005).
  Physical health burdens of women with trauma histories and co-occurring substance abuse and mental disorders. Journal of Behavioral Health Services & Research, 32(2), 128-140. Link to PubMed.
  
  Nearly half of the women in the WCDV study reported serious physical health issues that affected their daily lives.
  Link to Abstract »