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(CNN) — Combining treatments for post-traumatic stress disorder and substance abuse resulted in improved PTSD symptoms without worsening symptoms of substance abuse, according to a study released Tuesday in the Journal of the American Medical Association.

The findings, explain the Australian researchers, are contrary to conventional wisdom on how to treat PTSD and substance abuse, which commonly co-exist in patients. The common belief, they explain, has been that using the so-called “gold standard” of PTSD treatment might exacerbate substance abuse by resurfacing negative memories.

Therefore, people with substance abuse and PTSD have commonly been excluded from prolonged exposure therapy-based PTSD treatments and clinical trials using exposure therapy.

Prolonged exposure therapy is considered one of the most effective PTSD treatments. In fact, prolonged exposure therapy is the only “treatment for PTSD endorsed in a U.S. Institute of Medicine study as evidence based,” according to corresponding study author Katherine L. Mills of the University of New South Wales.

During the therapy, patients work with therapists to go back to their traumatic event and describe it in present tense, allowing the person to relive the trauma. By repeating this process, the brain reacts less severely over time, making the memory seem less traumatic.

University of New South Wales researchers enrolled 103 participants in their trial. All participants met the diagnostic criteria for both PTSD and substance abuse. The subjects were randomly selected to either receive both prolonged exposure therapy and treatment for substance abuse, or to only receive treatment for substance abuse.

At the nine-month mark, while both groups experienced reductions in PTSD symptoms, the subjects in the combined treatment group also showed a reduction in the severity of their PTSD symptoms without any increase in the severity of their substance abuse.

Barbara Rothbaum, a professor of psychiatry and PTSD expert at Emory University, calls the study results “practice-changing.”

“So many therapists are scared, because treating PTSD is a painful, grieving process,” for patients, she says, and this study provides evidence-based data that there is no increase in substance abuse when both treatments are combined. Rothbaum says these findings will benefit therapists who treat PTSD and patients who have both conditions.

Post-traumatic stress disorder is a mental health condition that occurs after a person is exposed to a terrifying event. PTSD, while often associated with veterans who’ve been exposed to the trauma of combat, can be experienced by anybody who’s been exposed to a traumatic event including natural disasters, assaults, a heart attack, the death of a loved one, or a major injury or accident.

PTSD symptoms include anxiety, experiencing nightmares or flashbacks, and its common for people with PTSD to avoid situations that will remind them of the frightening experience. Another common coping mechanism is self-medication leading to substance abuse in an effort to dull the devastating thoughts that PTSD can bring to its victims.

By Ann J. Curley – CNN

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