In a nonrandomized controlled trial, researchers studied the viability of psychiatric service dogs for the treatment of post-traumatic stress disorder (PTSD). Eighty-one veterans with PTSD were given a trained psychiatric service dog, and 75 veterans in the control group did not receive one. Both groups had access to other PTSD care. Over a three-month measurement period, the group with the service dogs had significantly lower PTSD symptom severity, significantly lower depression and anxiety, and better psychosocial functioning, as compared to the control group. The dropout rate in this study was substantially lower than other trauma- and non-trauma-focused treatments, leading the researchers to conclude that the dogs may be an effective complementary therapy for military service-related PTSD.