A fundamental premise of the psychiatric service dog therapeutic model, as promulgated by the Psychiatric Service Dog Society, is 24/7 human-canine partnership. The intensity of the partnership leverages a dog's innately observant nature to the human partner's benefit. As the dog becomes conditioned to the usual range of behaviors, attitudes, and dispositions of its mentally ill partner, the dog responds to the person's episodic manifestations of mental illness by manifesting an unusual behavior. Each dog is unique in the signal or alert it provides, such as nibbling a handler's fingers or toes, bumping a handler's elbow, whining, barking, pensive or worried looks, or apparent misbehavior (e.g., running around the handler in an excited manner uncharacteristic or ill-suited to the circumstances).

Since the dog and handler are together 24/7, the human partner takes note when her dog is behaving differently and uses this information to deduce that she likely is entering an episode of mental illness. This often silent exchange usually takes place before the human partner even is aware of her own nascent symptoms, which may include aggressive driving secondary to a hypomanic episode or hyperventilation due to an incipient panic attack. In the words of three psychiatric service dog handlers:

• “When a psychiatric service dog alerts, its handler acquires new information about triggers that are affecting her brain and precipitating symptoms.”

• “I found that if I am not calm, [my dog] begins to act up. This is my clue to do an internal check to see what is really going on inside.”

• “When my dog alerts, I am given an opportunity to act on the information long before the development of symptoms that would otherwise require inpatient care.”

It is not yet understood what exact cues a dog may be picking up on. They may be subtle behavioral cues, or they may be olfactory cues such as a subtle change in the smell of one's breath or uncharacteristic sweat gland secretions on one's skin. The acquisition of insight in this context renders the human partner better equipped to mitigate the episode through cognitive interventions, risk-reduction behaviors, PRN medications, or calling one's healthcare provider for assistance.

In fact, a vital therapeutic function of a psychiatric service dog is to assist the human partner in cultivating insight into her unique manifestations of mental illness. Since mental illness is known to impair an individual's degree of insight, this therapeutic function proves invaluable to savvy mental health patients. One psychiatric service dog handler characterizes the interaction this way: “[My dog] and I have a sort of feedback loop going on. I read her, reading me, and this helps me to better modulate my reactions and behaviors.”

The Society promotes psychiatric service dogs as an adjunct to ongoing standard-of-care mental health treatments. They are to be used in addition to a consumer's existing mental health treatment plan rather than as a substitution. To the best of our knowledge, no payers reimburse the costs associated with training a psychiatric service dog, which at a minimum costs $1,000, excluding the cost of purchasing the dog. Such a serious training requirement represents a real financial obstacle for many. Simply put, dogs cost money. Most mental health consumers train their own psychiatric service dog. Some training guidance is provided through the Society's Web site (https://www.psychdog.org) and its handler Listserv, but individuals are strongly encouraged to retain a professional dog trainer for one-on-one training sessions to establish a solid training foundation.

In addition to providing a therapeutic function, psychiatric service dogs may be trained to perform tasks that assist their human partners. For example, many handlers have trained their dogs to remind them to take medication at a specified time. The reliability of this task derives from the natural clock in canine brains and a dog's uncanny ability to associate a particular time of day with the reliable provision of treats, which could be located next to the human partner's mid-afternoon pill bottle.

Dogs have been trained to wake handlers experiencing night terrors, as a result of post-traumatic stress disorder, and turn on the lights so that they can regroup (the dog could activate a “touch lamp” or pull a string attached to a light). A famous author with PTSD trained her dogs to check a residence or hotel room for the presence of other people so that she could feel safe to enter.

An individual with panic disorder trained his dog to lie on top of him, providing warmth so that he can recover from the cold sweat and chills that often accompany panic attacks. For many people with psychiatric disorders, calling one's dog to sit quietly while stroking its fur is enough of a therapeutic redirection of one's attention to mitigate acute symptoms, such as the compulsion to bolt, self-injure, or repeatedly check door locks.

Psychiatric service dogs can be distinguished from ordinary pets. Service dogs are trained in three domains: basic obedience, public access skills, and disability-related tasks or therapeutic functions. A service dog will behave impeccably. It will not eliminate inappropriately, bark incessantly, jump on people, or lunge at other dogs. Much of the time, the dog will appear relaxed yet attentive to the handler. Most service dogs wear a vest, backpack, or harness clearly labeled “service dog,” although such labeling is not required by law.

A legitimate service dog handler should be able to describe how her psychiatric service dog assists her, whether through the performance of disability-related tasks or the provision of therapeutic functions. Granted, it may be difficult for the handler to explain the precise phenomenology of her dog's assistance, but it should not be impossible. A corollary challenge would be to ask a patient to explain how talk therapy works for her. You may not get the polished response you would expect from a psychologist, but the response should make sense.

The Society is studying the efficacy of psychiatric service dogs. In addition to an arsenal of anecdotes, formal psychiatric service dog handler survey data reflect refractory symptom reduction among 84.4% (n = 54) of the respondents polled. Forty percent (n = 26) reported reduced use of psychotropic medication subsequent to psychiatric service dog partnership. In the past year, the Society submitted to the National Institutes of Health three grant proposals for randomized clinical trials utilizing psychiatric service dogs. Two proposals were not funded, and the third is pending. A longitudinal outcomes study also is in the planning stages.

No doubt the excavation of knowledge about psychiatric service dogs still is under way. There is more to learn and, at least for now, the key informants are mental health consumers. The Society will continue to codify this developing body of knowledge, as it has for the past ten years, and extract key findings for dissemination on its Web site.