Regarding PTSD, all the study groups showed symptom reductions during treatment. After treatment ended, patients who had undergone prolonged exposure therapy showed decreases in PTSD symptoms, but the reductions did not reach statistical significance.
This null finding was attributed to the low attendance at these sessions. Also, all participants received some supportive counseling, which might have masked the effects of prolonged exposure therapy, the researchers said.
An exploratory analysis was performed to elucidate this unexpected result. It showed that 70% of participants who received naltrexone plus prolonged exposure therapy achieved a "low" level of PTSD severity at 12 months, as did 55% of those who received prolonged exposure therapy plus placebo. In comparison, 44% of those who received naltrexone only and 37% of those who received placebo only achieved a low level of PTSD severity.
This, taken together with the lower relapse rate among patients who received prolonged exposure therapy, suggests that the therapy protects against relapses in alcohol dependence, Dr. Foa and her colleagues said.
It was also "encouraging" that patients who attended six (half) or more of the prolonged exposure therapy sessions "benefitted substantially from treatment, suggesting that a relatively low dose of prolonged exposure therapy is effective in this population," they added.
This study was funded by the National Institute on Alcohol Abuse and Alcoholism. No relevant financial conflicts of interest were reported.