People experiencing the anxiety, sleep disturbances, flashbacks and other symptoms of post-traumatic stress disorder (PTSD) often use alcohol as a form of self-medication. So it isn’t unexpected that PTSD patients can also exhibit signs of alcohol dependence.

Treating PTSD may increase alcohol consumption. But the findings of a recent study suggest that the opposite may be true. Exposure therapy, a well-established PTSD treatment, can actually help patients with alcohol problems.

Exposure therapy enables patients to gain control over the troubling memories that characterize PTSD. It involves replaying or rehearsing the traumatic event or a scene symbolic of the trauma, sometimes within a day of the event itself, but more often gradually and consistently, under the guidance of a therapist.

Some investigators believed that prolonged exposure therapy increased alcoholic consumption in PTSD patients. The new study suggests that this need not be the case.

A reduction in drinking was found even in the group of patients given prolonged exposure therapy without naltrexone.

Researchers at the University of Pennsylvania found that the naltrexone, a drug well known for treating alcohol abuse, reduced drinking severity and alcohol craving in individuals suffering from both PTSD and alcohol dependence. The effects were measured in a study of 165 people with PTSD and alcohol dependence.

Participants were given either naltrexone or placebo and provided supportive counseling during the entire study, which began in 2001 and ended in 2009. Half were also given prolonged exposure therapy, a cognitive-behavioral treatment for PTSD developed by the study’s lead investigator, Dr. Edna Foa. The study was a randomized, double-blind placebo-controlled trial, so participants were assigned randomly to conditions and did not know what group they were in.

Naltrexone significantly reduces relapse and alcohol craving in patients with alcohol dependence. Scientists believe it works by controlling the brain’s dopamine pathway, which affects reward circuits in the brain. PTSD patients who had been given naltrexone had an 8% lower incidence of days drinking than those who had been given placebo.

However, the study found that prolonged exposure therapy did not increase alcohol drinking or craving, contrary to the opinions of other investigators. Instead, a reduction in drinking was found even in the group of patients given prolonged exposure therapy without naltrexone.

Six months after the treatments were discontinued, the patients were brought in for a follow-up study. While almost all of the patients exhibited an increase in alcoholic drinking following treatment, the group that had been given prolonged exposure therapy plus naltrexone had the smallest increase.

The authors contend that their results demonstrate that "patients with comorbid alcohol dependence and PTSD benefit from naltrexone treatment." Other studies have even demonstrated that alcohol consumption can rewire brain circuits so they are less adaptable to traumatic stress.

This study is published in the Journal of the American Medical Association