The small study found that 80 per cent of participants with PTSD improved to the point where they were no longer considered to be suffering from the condition after 15 sessions of cognitive behavioural couple therapy.
The work, which was led by a researcher at Ryerson University in Toronto, is published in this week's issue of the Journal of the American Medical Association.
Lead author Candice Monson says the idea to look at whether couples therapy was useful in treating PTSD stems from the growing awareness that the condition places relationships under severe stress and can lead to divorce.
While some clinicians have used cognitive behavioural couples therapy for PTSD, it is not currently used extensively for the condition.
This study compared disability status and relationship satisfaction levels in 20 couples randomly assigned to get the therapy versus 20 who were put on a waiting list for the treatment.
The therapy involved 15 sessions lasting 75 minutes apiece. The couples who didn't originally get the therapy were offered it after the study was completed.
The study included both heterosexual and same-sex couples but in all cases only one member of the couple was suffering from PTSD.
The study was funded by the U.S. National Institute of Mental Health.
"The take-home message is that of the individuals at the end of treatment that were assessed, that 80 per cent of them lost their diagnosis of PTSD," says Monson, who is a professor of psychology and director of clinical training at Ryerson.
"And 80 per cent of them had a clinically meaningful response, meaning that their scores changed enough that you should see actual social changes in that person — so impairment related improvements."
Monson says those results are similar to what one would expect to see if the PTSD sufferer received individual talk therapy.
But the couples therapy offers the benefit of treating both the impairment and the problems it creates in the relationship with the sufferer's partner — an important bonus at a time of shrinking resources, she says.
An editorial published with the study, however, raises questions about its design, suggesting the participants included may not have been representative of most people suffering from PTSD.
Lisa Najavits of Veterans Affairs Boston Healthcare System says the PTSD sufferers were largely white and employed, and virtually none had a substance abuse disorder at the start of the study. As well, couples were excluded if there was evidence of severe intimate partner aggression in the previous year, or if both partners had PTSD.
"Thus the trial ... cannot be interpreted as being applicable to couples with these additional challenges, which may be the couples in greatest need of help," she writes. "Hopefully future trials will evaluate couples therapy for PTSD among a broader range of patients."
Monson takes exception to the suggestion that the people in her study were atypical of PTSD patients, saying their starting scores — assessed by experts — were well within the range of scores seen among PTSD sufferers.
She says her group, which includes researchers from the medical schools at Harvard and Dartmouth universities, is continuing the work looking at a number of different groups. They include partnerships in which both members have PTSD, sibling pairs and parent-child pairings.