In This Issue

The impact of service dogs on posttraumatic stress disorder in the veteran population

This article offers an interesting perspective on service dogs in clinical practice.

By Holloway Marston and Alicia Kopicki

More than 2 million veterans have deployed to combat zones during this most recent conflict, of whom 13–20 percent are believed to have developed posttraumatic stress disorder (PTSD; RAND Corporation, 2008; Sayer et al., 2010). Data suggest that only 50 percent of these returning veterans access care, and merely 40 percent of these treatment seekers experience significant improvement in their symptoms of PTSD. This suggests that only a fraction of those with symptoms is improving because only 20 percent of all returning veterans with PTSD are seeing a reduction in the frequency, intensity, and duration of their symptoms of PTSD (Hoge, 2011). This unfortunate reality is believed to be due to factors such as stigma, lack of trust in mental health providers, and the belief that available treatments are ineffective (Hoge, 2011; Sayer et al., 2010).

Veterans have provided anecdotal reports stating that service dogs have helped them recover from PTSD when they could not find relief from other interventions (Ruiz, 2012; Winkle, Crowe, & Hendrix, 2012). Alternative treatments such as this could help the 40 percent of veterans who do not experience improvements after participating in treatments such as prolonged exposure (PE) and cognitive processing therapy (CPT), which are considered the gold standards for treating PTSD (Monson & Friedman, 2006). However, lack of awareness and empirical evidence in support of this intervention appear to have prevented this form of treatment from being widely used and accepted by mental health service providers who treat veterans affected by PTSD (Foreman & Crosson, 2012).

In response to the large number of veterans returning home from combat affected by PTSD, nonprofit organizations have begun training service dogs as an alternative intervention for this population, because of the high volume of requests from returning veterans for this form of treatment (Foreman & Crosson, 2012). There is a gap between the demand and availability of service dogs largely due to the lack of research on which funding and grant requests are based (Sachs-Ericsson, Hensen, & Fitzgerald, 2002). Many of these organizations have been accredited by Assistance Dogs International, which is the certifying body tasked with setting standards of excellence within this specialty (Sachs-Ericsson et al., 2002). An accredited service dog is protected under the Americans With Disabilities Act, indicating that the dog cannot be refused entrance anywhere, including restaurants and airports (Shubert, 2012). Certified organizations train highly skilled service dogs for the purposes of helping returning veterans recover from PTSD.

Service dogs are trained to complete many complex tasks that are intended to provide support to veterans when they experience difficulty with their symptoms of PTSD (Foreman & Crosson, 2012). Esnayra and Love (2005) described their findings when studying service dog behaviors and found the dogs can be trained to confirm the safety of a room by patrolling its perimeter for the purposes of providing the veteran with a greater sense of safety prior to entering (Esnayra & Love, 2005). A service dog can also turn on the lights to interrupt a veteran's nightmare, remind the veteran to take medication by alerting him or her at the proper times, and can even prevent a veteran from being startled by nudging him or her gently when someone is unexpectedly approaching or by blocking a person who is coming too close to the veteran (Esnayra & Love, 2005). These behaviors are intended to assist veterans with PTSD because the service dogs provide support and increased means of coping with the associated symptoms such as hypervigilance, fear, nightmares, the fight-or-flight response, and impaired memory (Esnayra & Love, 2005).

Based on anecdotal reports, once veterans begin to manage their PTSD symptoms after being paired with a service dog, their quality of life has improved (Foreman & Crosson, 2012). Veterans have reengaged in many life tasks that their symptoms previously prevented them from participating in, such as work, school, and socializing with family and friends (Freedom Service Dogs, personal communication, December 5, 2012). In addition, veterans reported that they depended less on medications to cope with symptoms that have side effects, such as drowsiness, which further impeded their ability to engage in life tasks. Hoge (2011) reported that ~ 60–80 percent of all returning veterans affected by PTSD will not recover through treatments such as CPT or PE. Monson and Friedman (2006) stated that alternative interventions are necessary for the purposes of treating PTSD, because in their estimates, the current available evidence-based treatments did not resolve symptoms in 50 percent of the veterans who received them. Moreover, many veterans reported that they would prefer not to engage in treatments such as CPT or PE (Hoge, 2011). Although it is clear that CPT and PE are an important part of recovery for some veterans, experts have indicated that alternative treatments, such as the service dog interventions, are needed to assist veterans who have not found success with current evidence-based therapies (Hoge, 2011).

Despite these positive anecdotal reports from veterans, using service dogs as a treatment for PTSD is not yet widely accepted by providers who treat veterans. The U.S. Department of Veterans Affairs (VA) has expressed concern about the efficacy of this treatment because of the belief that it has the potential to cause veterans to not attribute improvements to their own ability but rather to the support of their dog. For example, it has been suggested that service dogs could negatively affect exposure interventions, because when the veteran engages in behaviors that were previously feared, he or she may attribute this change to the presence of the dog rather than his or her own ability to overcome the fear (McIntosh, 2009). For these reasons, as well as the lack of sufficient evidence of its effectiveness, the VA does not support the use of service dogs for treating PTSD symptoms (McIntosh, 2009). Other researchers also acknowledge the lack of empirical evidence for this treatment (Love & Esnayra, 2009; McIntosh, 2009).

Theoretical Framework

The literature suggests that service dogs are effective because they address the biological, psychological, and social aspects of PTSD symptoms. On a biological level, Yount, Olmert, and Lee (2012) suggested that when individuals interacted with dogs, their stress levels were reduced, as evidenced by a decrease in cardiac reactivity and cortisol. These responses were associated with reductions in hyperarousal, social isolation, and pain and sleep disturbances, which are important indicators that PTSD symptoms are becoming less severe (Yount et al., 2012). Evolutionary theory suggests that humans intrinsically find other living things comforting, which can lead to the calming of aroused physiological states (Henry & Crowley, 2011). Research suggests that when humans interact with animals, the physiological stress reaction is reduced, as evidenced by lower heart rates and cortisol levels (Sachs-Ericsson et al., 2002; Yount et al., 2012). Data suggest that increases in oxytocin and dopamine, as well as a reduction in cortisol, result in this calming response for individuals who interact with dogs (Horowitz, 2008). Oxytocin is a stress-reducing hormone, and interactions with dogs have been found to increase this neurochemical (Yount et al., 2012). Calming interactions with dogs, including petting and quietly talking to them, have been shown to result in a physiological stress reduction response (Yount et al., 2012). These interactions may even serve as grounding exercises, which are coping skills taught to veterans for the purpose of helping them manage their symptoms of PTSD (Esnayra, 2007).

Oxytocin has also been found to play an important role in the physiology of PTSD (Yount et al., 2012). Research suggests that oxytocin reduces symptoms related to PTSD such as anxiety, fear responses, hyperarousal, interpersonal difficulties, social isolation, physical pain, and sleep disturbances (Yount et al., 2012). Additional empirical findings suggested that oxytocin reduces interpersonal conflicts, negative communication, aversive conditioning of social stimuli, and the stress response (Yount et al., 2012). The neurochemical has also been found to increase accurate identification of emotional states in others, the processing of positive social information, and the use of social support (Yount et al., 2012). Pointedly, oxytocin has been found to positively affect symptoms of PTSD in combat veterans, and this neurochemical was found to decrease the physiological response that occurred when exposed to memories of combat trauma (Yount et al., 2012).

Oxytocin acts on the hypothalamic-pituitary-adrenal (HPA) axis, which is believed to be the pathway in the brain that is affected by PTSD (Hoge, 2011; Yount et al., 2012). Oxytocin has also been shown to decrease cytokines, adrenocorticotrophic hormone, and cortisol, which are the substances in the brain that activate the HPA axis, resulting in the increased physiological responsiveness associated with PTSD (Horowitz, 2008; Yount et al.,2012). In addition, oxytocin acts on the amygdala and other important structures of the central nervous system that are believed to be involved in the physiological processes of PTSD, causing a connection in the prefrontal cortex (Yount et al., 2012). This is an important occurrence related to PTSD because this connection with the prefrontal cortex increases appraisal and evaluation of stimuli, which could reduce the experience of freeze reactions or sensing false danger triggers in a veteran's environment (Yount et al., 2012). Therefore, the positive effects of oxytocin appear to result in many improved responses that could translate into an enhanced quality of life for veterans who are paired with service dogs. Experiences such as reduced hypervigilance and improved connections with sources social supports as a result of oxytocin are examples of outcomes that would help veterans recover from their trauma with the assistance of their service dogs.

Psychologically, Yount et al. (2012) reported that individuals who endorsed having a bond with their dogs felt that the dogs served as a buffer against stressors. Attachment theory suggests that a service dog provides the veteran with a secure base effect (Valsecchi, Prato-Previde, Accorsi, & Fallani, 2010). Escolas et al. (2012) found that veterans with PTSD are significantly more likely to report experiences consistent with an insecure attachment style. This study reported that PTSD is correlated with attachment style because of the way in which serious symptoms can negatively affect interactions with a veteran's support system (Escolas et al., 2012). In addition, the attachment style from which individuals interact reflects the way in which they see themselves and others (Escolas et al., 2012). Furthermore, combat PTSD can be interpreted by veterans as an interpersonal violation, commonly resulting in withdrawal, impairment, and disruptions in attachments (Escolas et al., 2012). Therefore, if a service dog is capable of helping to repair a veteran's ability to form attachments, his or her overall quality of life would also likely improve as a result.

Veterans with secure attachments are much less likely to be affected by symptoms of PTSD (Escolas et al., 2012). Empirical studies have indicated that service dogs form a strong attachment with their paired individual (Valsecchi et al., 2010). (Escolas et al., 2012) indicated that “any relationship in which proximity to the other affects security is an attachment relationship” (p. 58). Attachment theory suggests that dogs stimulate a nurturing response from individuals who interact with them (Horowitz, 2008). A strong attachment with a service dog could be particularly important in the recovery process and overall improved quality of life for many combat veterans, because of the potential to overcome the inability to feel connected to others as a result of their PTSD (American Psychiatric Association, 2013).

Finally, on a social level, Sachs-Ericsson et al. (2002) found that individuals with service dogs felt less isolated socially and felt more comfortable when initiating social interactions with others. Social provisions theory proposes that the service dog provides the veteran with feelings of self-worth, as well as nurturance, and a consistent source of support (Henry & Crowley, 2011). One study found that disabled individuals experienced reduced feelings of loneliness after being paired with their service dogs (Winkle et al., 2012). In addition, disabled individuals also stated that they felt an increased sense of security once being paired with their service dog because of the acquired emotional support gained from the dog (Winkle et al., 2012).

Social mediation theories state that the service dog stimulates conversation and impromptu interactions with the community, as well as enhances the veteran's social desirability (Henry & Crowley, 2011). Also, Winkle et al. (2012) stated that service dogs have a positive effect on socialization and community involvement for paired individuals. In addition, Horowitz (2008) reported that the bond between a human and a dog tends to promote social cohesion. Data suggest that community members smiled at and spoke to individuals paired with service dogs more frequently than disabled individuals without service dogs (Eddy, Hart, & Boltz, 1988). These findings are particularly important for veterans who may experience social isolation because of a disabling mental health diagnosis, because service dogs appear to promote positive interactions with others (Eddy et al., 1988). This idea is supported by one study's findings that 75 percent of disabled individuals surveyed reported making new friends after being paired with their service dogs (Sachs-Ericsson et al., 2002; Winkle et al., 2012). This is significant because increasing social support for veterans affected by PTSD as a result of their combat experiences has been shown to positively influence recovery from PTSD and improve their quality of life (Bailey, Eng, Frisch, & Snyder, 2007; Escolas et al., 2012).

Treatment Effects

Esnayra and Love (2005) reported positive results from their study, which looked at the effects of psychiatric service dogs on the symptoms of individuals diagnosed with a mental illness. Their findings indicated that more than 86 percent of individuals in their study with agoraphobia and anxiety reported a reduction in their symptoms (Esnayra & Love, 2005). In addition, greater than 80 percent of their respondents diagnosed with PTSD, panic, and depression reported a decrease in the mental health symptoms they experienced. Specifically, more than 84 percent reported a decrease in symptoms as a result of the service dog intervention (Esnayra & Love, 2005). The investigators also indicated that 40 percent of their participants stated that they were able to reduce the amount of medication needed to treat their symptoms after being paired with a service dog (Esnayra & Love, 2005). These findings are encouraging because they specifically relate to symptoms of anxiety, depression, and PTSD, which are diagnoses that veterans must frequently cope with as a result of their service (Jakupcak et al., 2009).

Knisely, Barker, and Barker (2012) reported within the U.S. Army Medical Department Journal that individuals who engaged in animal-assisted therapies experienced a reduction in their anxiety and depression symptoms. Similarly, research findings suggested that individuals who lived alone or were institutionalized experienced a reduction in symptoms of depression and anxiety after interacting with a therapy dog (Shubert, 2012). Yount et al. (2012) also reported data suggesting that symptoms of depression showed improvement following animal interactions. Furthermore, Sachs-Ericsson et al. (2002) reported that 70 percent of participants indicated a reduction in the level of anxiety and depression they experienced after being paired with their service dog. Most pertinently, Winkle et al. (2012) stated that service dogs have also been shown to improve the quality of life of paired individuals, as well as their symptoms of depression. These findings are promising and suggest that similar effects might be found with members of the veteran population once paired with a service dog specially trained for treating symptoms of PTSD.


A well-designed research study considering the issues presented in this article is relevant for returning Iraq and Afghanistan war veterans because it could provide empirical support that service dogs are effective for treating their PTSD symptoms. Such a study is currently being conducted at the Adler School of Professional Psychology to investigate many of the variables discussed. The positive anecdotal reports from veterans about the benefits of service dogs for PTSD symptoms suggest that this treatment modality should be investigated and subsequently made available to more veterans. Many returning veterans are requesting treatment in the form of a specially trained service dog, as evidenced by the long waiting lists with the nonprofit organizations. Because data suggest that this population may not typically reach out for support when needed, conducting a well-designed study to determine the efficacy of the treatment is a necessary contribution to the field.

Many have advocated that efficacy studies of alternative treatments for PTSD are needed so that veterans can be informed about other treatments that have been shown to alleviate symptoms (Hoge, 2011). Considering that this is a relatively new method of therapy, a well-designed study could provide reliable evidence of its effectiveness, which would support veterans' testimonies that service dogs do improve their quality of life (Ruiz, 2012). Under controlled conditions, the objective of the study is also to rule out alternative explanations for how service dogs heal veterans.

These findings would also be relevant to mental health professionals who wish to refer veterans with PTSD symptoms for alternative treatments. Mental health professionals could base their treatment recommendations on studies that demonstrate the effectiveness of service dogs in alleviating symptoms of PTSD in veteran populations. Policy changes and support for the use of this intervention will only occur if awareness is brought to the mental health field through research. As stated, empirical evidence supporting the use of service dogs for PTSD is needed to effect this change.

Research also has the distinct opportunity to improve funding opportunities through grants for the nonprofit organizations that train and provide service dogs to veterans. Researchers who provide data to these organizations could offer them an opportunity to showcase their efficacy to prospective grant providers. A carefully designed study such as the one advocated for within this article is currently being conducted by a research team at the Adler School of Professional Psychology along with community partners who train and provide accredited service dogs free of charge to returning veterans.

The study is currently in the data-gathering and participant recruitment phase. Plans to publish the findings by the end of this year are currently in place.

For further information, contact Holloway Marston and Alicia Kopicki.


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