After running away from home at 13, Alicia was pulled into a small-time child-prostitution ring and repeatedly abused until she escaped three years later. The experience left scars, but it wasn’t until she was sexually assaulted again during her junior year of college that she developed post-traumatic stress disorder, causing her to constantly relive her trauma in nightmares and flashbacks.

“I thought I had escaped and it was over,” Alicia says. But the assault “proved me wrong, that this isn't a fresh new happy life from here on out.”

Now 26, Alicia rarely leaves her apartment. After taking a leave of absence from grad school, she lost her student insurance—and with it, the therapy that had been helping her cope. She has been searching wildly for something to fill in, and says she may have finally found it in the form of a Doberman puppy named Hera, who she is training to be her service dog.

Traditionally, service dogs have been used for people who are blind, deaf, or have other physical disabilities. Recently they’ve shown promise for people with psychological ailments as well, including depression, bipolar disorder, autism, and especially PTSD. Preliminary studies from the Department of Veterans Affairs (VA) and the Department of Defense suggest that service dogs can benefit traumatized soldiers, who report improvements in their anxiety, sleep, and social skills after working with the dogs.

Although PTSD is closely associated with combat, sexual-assault survivors are diagnosed with the disorder at an even higher rate than veterans—about 30 percent of rape victims develop PTSD at some point, according to the National Violence Against Women Prevention Research Center, compared to about 20 percent of veterans. Experts say that service dogs could be beneficial for sexual-assault victims as well, and may even be uniquely suited to help them overcome their issues with trust and relationships.

Most civilians with PTSD, however, don't have the resources to get a service dog, which costs upwards of $20,000. Part of the problem is that service-dog research is scattered and underfunded (pharmaceutical companies aren’t currently interested in this non-drug therapy). But experts resoundingly agree that the existing anecdotal evidence deserves further investigation.

“What there really desperately needs to be is a good study that looks at the effects of service dogs,” says Colonel Elspeth Cameron Ritchie, chief clinical officer for Washington, D.C.’s Department of Mental Health and a retired U.S. Army psychiatrist. “If the dog considerably improves quality of life, which is what I’ve seen, it's almost indescribable how much its worth for that person.”

In the meantime, we still don’t know exactly how service dogs can most effectively help PTSD sufferers. Without further study there is little guidance available for people like Alicia, and clinicians worry about training animals incorrectly.

“Clearly there are a lot of people benefiting psychiatrically from dogs. We just need to understand why,” says Captain Robert Koffman, a Navy psychiatrist at the National Intrepid Center of Excellence, a medical-research institution in the Department of Defense.

Most research to date has been done by the military. The DOD is currently conducting a study based on an earlier VA program called Paws for Purple Hearts, in which soldiers with PTSD train service dogs for their comrades with physical disabilities as a kind of occupational therapy. In a 2012 evaluation of Paws For Purple Hearts in the Unites States Army Medical Department Journal, soldiers in the program said that working with the dogs helped them feel more aware of and in control of their emotions. They also reported improvements in their self esteem and ability to interact with others.

Getting a dog to obey you requires a confident yet soothing demeanor, says Rick Yount, the clinical social worker who developed Paws for Purple Hearts. He hypothesizes that training the dogs helps veterans practice modulating their stress level and tone of voice—skills they can extend to conquer PTSD symptoms. Participants saw other benefits from the program as well, including better medication adherence and sleep quality. “With the dogs they are getting substantially more sleep—sometimes five or six hours instead of two,” Yount says.

Service dogs may also offer support in less tangible ways. People with PTSD, who otherwise tend to isolate themselves from others, seem to open up in the company of the dogs, Koffman says. Koffman has a psychiatric service dog, Ron, who he often brings to work with him. “A lot of patients who would otherwise not want to see a therapist will come into my office just to see the animal,” he says.

This aspect of service dog assistance may be especially beneficial for sexual-sassault victims, who often have been abused by people close to them and tend to have more issues with trust and relationships. “Trauma from an explosion or natural disaster typically won't cause the same level of emotional withdrawal or fear of other people,” says Christopher P. Lucas, an associate professor of psychiatry at New York University School of Medicine.

Koffman and Ritchie believe that the dogs facilitate social interaction by increasing the amount of the hormone oxytocin in the brain. Oxytocin promotes bonding and trust and has been shown in previous experiments to be released when we come in contact with babies, dogs, and other cute creatures. This oxytocin boost may put PTSD sufferers at ease around others and make them more responsive to traditional talk therapy, the researchers hypothesize.

In contrast to the military's training-as-occupational-therapy approach, some sexual assault survivors and service dog organizations are are teaching dogs to perform physical tasks to assist their owners—like turning on lights—more in the mold of a traditional service dog. For PTSD, dogs have been trained to do things like wake people from nightmares and create a buffer against crowds. Alicia wants to teach Hera to guard her back when she is turned to face an ATM or an aisle in the grocery store, which usually causes her anxiety. She also wants to train Hera to lead her to safety if she starts dissociating—disappearing into painfully vivid memories of abuse, a PTSD symptom—in public.

Koffman has reservations about this tactic: He worries that training service dogs to perform assistive tasks could help people with PTSD avoid addressing their issues, inadvertently reinforcing distorted fears they may have about the world. More research is needed to determine what works and what doesn't, he says.

“We need to be smart about what we’re researching and make sure it's based on sound clinical sense,” Yount agrees. In an effort to tease out which aspects of working with a service dog are most helpful for PTSD, the VA has taken up a study comparing the effects of service dogs who perform physical tasks and dogs who just provide emotional support.

Although Alicia is training Hera like a traditional service dog, she seems to be benefitting from her presence in other ways as well. When Alicia talks about a difficult subject, she strokes Hera, who stops wriggling around and settles against Alicia’s side, seeming to know that she needs to be more than a playful puppy at this moment.

“I am at minimum now leaving my apartment,” Alicia says. “Anyone who has ever had a dog and had a rough week knows that having to walk your dog and get your shoes on and go outside makes a huge difference.”