Quantifying the Efficacy and Role of Service Dogs for Military Veterans With PTSD

The long-term research goal is to evaluate the safety and efficacy of service dogs as a complementary intervention to enhance biopsychosocial functioning in special populations. The objective is to conduct a methodologically rigorous trial to quantify the therapeutic efficacy of service dogs on clinically-important outcomes for veterans with PTSD. Based on preliminary findings and qualitative reports, the central hypothesis is that military veterans with PTSD who are provided service dogs will experience reduced PTSD symptoms related to socio-emotional functioning and arousal modulation. The rationale for this research is that its successful completion will provide an evidence-based demonstration of the efficacy and role of an increasingly used yet poorly tested complementary intervention. The completion of this project is expected to established an initial demonstration of the therapeutic efficacy of service dogs in this population, as well as possible mechanisms of action via specific biological pathways and human-canine interaction profiles.

• Service Dog (Behavioral): A service dog trained to perform tasks that are specific to PTSD

Primary outcomes

• PTSD Severity and Symptoms Via Self-report [3 months]: Posttraumatic Stress Disorder Checklist for DSM-V (PCL-5); range 0-80; higher scores indicate worse outcome.
• PTSD Severity and Symptoms Via Clinician Rating [3 months]: Clinician-Administered PTSD Assessment for the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition DSM-V (CAPS-5); range 0-80; higher scores indicate worse outcome.
• Depression [3 months]: Patient Reported Outcome Measurement Information System (PROMIS) Adult Short Form (SF) v1.0 - Emotional Distress - Depression 8a; T-score range 38 to 81; 50 indicates the population mean with a standard deviation of 10; minimally important difference greater than or equal to 3 points; higher scores indicate worse outcome.
• Anxiety [3 months]: Patient Reported Outcome Measurement Information System (PROMIS) Adult Short Form (SF) v1.0 - Emotional Distress - Anxiety 8a; T-score range 37 to 83; 50 indicates the population mean with a standard deviation of 10; minimally important difference greater than or equal to 3 points; higher scores indicate worse outcome.

Secondary outcomes

• Social Isolation [3 months]: Patient Reported Outcome Measurement Information System (PROMIS) Adult Short Form (SF) v2.0 - Social Isolation 8a; T-score range 33 to 76; 50 indicates the population mean with a standard deviation of 10; higher scores indicate worse outcome.
• Companionship [3 months]: Patient Reported Outcome Measurement Information System (PROMIS) Adult Short Form (SF) v2.0 - Companionship 6a; T-score range 24 to 64; 50 indicates the population mean with a standard deviation of 10; higher scores indicate better outcome
• Ability to Participate in Social Activities [3 months]: Patient Reported Outcome Measurement Information System (PROMIS) Adult Short Form (SF) v2.0 - Ability to Participate in Social Roles and Activities 8a; T-score range 25 to 65; 50 indicates the population mean with a standard deviation of 10; higher scores indicate better outcome.
• Mental Health Quality of Life [3 months]: Veterans Rand 12-item Health Survey (VR-12) - Mental Health Component; range 0-100; higher scores indicate better outcome.
• Psychological Well-being [3 months]: Bradburn Scale of Psychological Wellbeing (BSPW); range -5 to 5; higher scores indicate better outcome.
• Life Satisfaction [3 months]: Satisfaction with Life Scale (SLS); range 3-35; higher scores indicate better outcome.
• Resilience [3 months]: Connor-Davidson Resilience Scale (CDRS); range 0-40; higher scores indicate better outcome.
• Anger [3 months]: Patient Reported Outcome Measurement Information System (PROMIS) Adult Short Form (SF) v1.1 - Emotional Distress - Anger 5a; T-score range 32-82; 50 indicates the population mean with a standard deviation of 10; higher scores indicate worse outcome.
• Daily Socio-emotional Experiences [3 months]: Ecological momentary assessment (EMA) Social interaction quality; range 0-6; higher score indicates better outcome.

Other outcomes

• Work and Activity Participation [3 months]: Work Productivity and Activity Impairment Questionnaire (WPAIQ)
• Suicidal Ideation [3 months]: Columbia Suicide Severity Rating Scale (CSSRS)
• Sleep Quality [3 months]: Pittsburgh Sleep Quality Assessment (PSQI)
• Sleep Disturbance [3 months]: Patient Reported Outcome Measurement Information System (PROMIS) Adult Short Form (SF) v1.0 - Sleep Disturbance 8a
• Sleep Actigraphy [3 months]: Actiwatch 2 (Philips Respironics)
• Salivary Cortisol Awakening Response [3 months]: Passive drool method (Salimetrics)
• Electrodermal Activity (Skin Conductance) [3 months]: Embrace wristband (Empatica, Inc.)

Sex: All, ages: 18 Years to any, accepts healthy volunteers

Inclusion criteria for veterans into the study will include:

* Applied for and approved to receive a dog from K9s For Warriors
* Military service on or after September 11, 2001
* Honorable discharge or current honorable service
* Diagnosis of PTSD
* No conviction of any crimes against animals.

Participant flow

Outcome results

• PTSD Severity and Symptoms Via Self-report (Primary), Mean, units on a scale: Service Dog 41.9 +/- 16.9; Waitlist Control 51.7 +/- 16.1 (p <.001)
• PTSD Severity and Symptoms Via Clinician Rating (Primary), Mean, units on a scale: Service Dog 30.2 +/- 10.2; Waitlist Control 36.9 +/- 10.2 (p <.001)
• Depression (Primary), Mean, T-score: Service Dog 58.9 +/- 9.5; Waitlist Control 61.4 +/- 8.0 (p .02)
• Anxiety (Primary), Mean, T-score: Service Dog 62.1 +/- 7.1; Waitlist Control 66.0 +/- 5.4 (p <.001)
• Social Isolation (Secondary), Mean, T-score: Service Dog 60.1 +/- 10.8; Waitlist Control 62.8 +/- 8.6 (p .001)
• Companionship (Secondary), Mean, T-score: Service Dog 48.5 +/- 10.1; Waitlist Control 45.2 +/- 9.3 (p .003)
• Ability to Participate in Social Activities (Secondary), Mean, T-score: Service Dog 45.2 +/- 8.3; Waitlist Control 49.6 +/- 6.3 (p <.001)
• Mental Health Quality of Life (Secondary), Mean, units on a scale: Service Dog 36.3 +/- 10.7; Waitlist Control 29.1 +/- 10.4 (p <.001)
• Psychological Well-being (Secondary), Mean, units on a scale: Service Dog -0.6 +/- 2.7; Waitlist Control -2.2 +/- 2.2 (p <.001)
• Life Satisfaction (Secondary), Mean, units on a scale: Service Dog 19.7 +/- 7.0; Waitlist Control 15.3 +/- 6.9 (p <.001)
• Resilience (Secondary), Mean, units on a scale: Service Dog 21.7 +/- 6.3; Waitlist Control 20.8 +/- 7.7 (p .02)
• Anger (Secondary), Mean, T-score: Service Dog 61.2 +/- 10.5; Waitlist Control 64.1 +/- 10.0 (p .009)
• Daily Socio-emotional Experiences (Secondary), Mean, units on a scale: Service Dog 4.2 +/- 1.5; Waitlist Control 3.9 +/- 1.5 (p 0.002)
• Work and Activity Participation (Other pre specified)
• Suicidal Ideation (Other pre specified)
• Sleep Quality (Other pre specified)
• Sleep Disturbance (Other pre specified)
• Sleep Actigraphy (Other pre specified)
• Salivary Cortisol Awakening Response (Other pre specified)
• Electrodermal Activity (Skin Conductance) (Other pre specified)

Adverse events

Time frame: Adverse events were collected through passive surveillance. Participants spontaneously reported adverse events during study assessment periods (equivalent reporting opportunities across both groups) and during a 3-week on-site group class at the service dog organization (intervention group only).

Serious adverse events by term

Other adverse events by term

• Results publication: Leighton SC, Rodriguez KE, Jensen CL, MacLean EL, Baus JJ, Ashbeck EL, Brown EA, Mehl MR, Taylor DJ, van Marle K, Schwichtenberg AJ, Bedrick EJ, O'Haire ME. Sleep-wake dynamics in veteran-service dog dyads: an exploration of overnight concordance. Sleep. 2025 Nov 10;48(11):zsaf177. doi: 10.1093/sleep/zsaf177. PMID 40580066
• Results publication: Leighton SC, Rodriguez KE, Jensen CL, MacLean EL, Davis LW, Ashbeck EL, Bedrick EJ, O'Haire ME. Service Dogs for Veterans and Military Members With Posttraumatic Stress Disorder: A Nonrandomized Controlled Trial. JAMA Netw Open. 2024 Jun 3;7(6):e2414686. doi: 10.1001/jamanetworkopen.2024.14686. PMID 38833250
• Results publication: Leighton SC, Rodriguez KE, Zhuang R, Jensen CL, Miller EA, Sabbaghi A, O'Haire ME. Psychiatric service dog placements are associated with better daily psychosocial functioning for military veterans with posttraumatic stress disorder. Psychol Trauma. 2024 Dec;16(Suppl 3):S707-S717. doi: 10.1037/tra0001543. Epub 2023 Jul 6. PMID 37410417

• Study Protocol and Statistical Analysis Plan (PDF, 2023-07-20)

• Marguerite O'Haire, Ph.D., Principal investigator, University of Arizona

NIH grants: R21HD091896