Childhood abuse raises drug users’ suicide risk

July 18, 2013  |  Media Contact: David Orenstein |  401-863-1862
A significant risk factor - A study in Vancouver, British Columbia, showed that the risk of suicide among drug users who had been abused as children was up to five times greater than in the general population.
A significant risk factor A study in Vancouver, British Columbia, showed that the risk of suicide among drug users who had been abused as children was up to five times greater than in the general population. Credit: M-J Milloy /University of British Columbia
A new five-year study that tracked more than 1,600 drug users found that severe abuse in their childhood – emotional, sexual, and to a lesser extent physical – significantly elevated their risk of attempting suicide. Screening for such abuse and offering treatment may help public officials and care providers reduce suicides.

PROVIDENCE, R.I. [Brown University] — For health professionals, the message from a new study in the American Journal of Public Health is clear: Asking patients about a history of childhood abuse can directly help assess their risk of attempting suicide. The evidence, authors say, shows that childhood abuse can have life-and-death consequences for the rest of a person’s life.

The longitudinal study of more than 1,600 drug users in Vancouver, Canada, found that “severe-to-extreme” abuse – particularly emotional or sexual – contributed significantly to the risk of future suicide attempts, even after accounting for a wide variety of other suicide-related factors. Less severe abuse, and physical or emotional neglect no matter the degree, did not contribute significantly to suicide risk.

“This study show that all of forms of childhood abuse, be it emotional, physical, or sexual, are important risk factors for suicide to various degrees,” said study lead author Brandon Marshall, assistant professor of epidemiology in the Brown University School of Public Health. Marshall began the work while a doctoral student at University of British Columbia and continued it as a postdoctoral fellow at Columbia University’s Mailman School of Public Health. “Care providers and health professionals should screen for these types of abuse and intervene whenever they see a situation of severe abuse, regardless of what type it was.”

To assess each subject’s history of childhood abuse and neglect, the researchers used the well-validated Childhood Trauma Questionnaire (CTQ) that produces a distinct score for each of five trauma categories (sexual, physical, and emotional abuse and physical and emotional neglect). When each participant entered the study, the researchers were able to quantify each participants’ self-reported degree of childhood trauma.

The study was part of two larger National Institute of Drug Abuse-funded studies led by UBC researchers — the Vancouver Injection Drug Users Study and the AIDS Care Cohort to Evaluate Exposure to Survival Services. Staff including trained nurses followed up with participants every six months during the study period. Among the questions was whether the subject had attempted suicide.

Over the course of the study 80 participants reported 97 suicide attempts. While that may seem like a low number out of more than 1,600 people, it is a rate of suicide attempts about five times greater than in the general population.

“I didn’t think there’d be enough power to show these relationships but there was and I think that demonstrates how detrimental childhood trauma can be,” Marshall said. “We saw extremely strong associations, which suggest that abuse has lasting mental health impacts well into adulthood.”

The researchers accounted in their analysis for many other factors that also predict suicide risk, such as depression, prior suicidal ideation or homelessness. They made several specific findings specific to abuse and its degree:

  • Only “severe-to-extreme” abuse (a CTQ score above 15) resulted in a significantly elevated risk of suicide attempts – 2.9 times for emotional abuse, 2.8 times for sexual and 1.6 for physical — compared to “none-to-minimal” abuse.
  • Among the 1,634 participants, 23 percent reported suffering “severe-to-extreme” sexual abuse, 25 percent suffered that degree of physical abuse, and 32 percent endured that degree of emotional abuse.
  • Nearly 200 participants were “lost to follow-up,” in some cases possibly because of a completed suicide. A statistical method that accounts for participants who dropped out raised the suicide risk from emotional abuse to 3.5 times, and physical abuse to 2.0 times. The risk from sexual abuse dropped slightly in that analysis to 2.5 times.

The best long-term public health strategy to reduce suicides would be to prevent child abuse in the first place, Marshall said, but his hope is that health providers can still make an impact through secondary prevention — identifying victims of such abuse and providing treatment meant to mitigate their elevated suicide risk.

The data also shed light on the resilience of the human spirit and the tragic limits of that resilience.

“There might be a level of resiliency in people who have experienced more minor forms of abuse, but very severe cases were linked with multiple suicide attempts,” Marshall said. “These results will allow us to focus future intervention efforts.”

In addition to Marshall, authors on the paper are Sandro Galea of Columbia University’s Mailman School of Public Health, and Evan Wood and Thomas Kerr of the Urban Health Research Initiative at the British Columbia Centre for Excellence in HIV/AIDS and the University of British Columbia–Vancouver.

Support for the study came from the National Institutes of Health (grants R01 DA011591 and R01 DA021525), the Michael Smith Foundation for Health Research (CI-SCH-085 05-1) and the Canadian Institutes of Health Research (MSH-80J36).

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