Table 1.
Characteristics and results of the 8 included controlled studies on PTSD symptom or depression severity
| First author, Publication year | Study design | N analysed (AAI/control) | Gender | Age (range, M, SD) | Type of experienced trauma | Participating animals | Treatment provider | AAI terminology | Control intervention | Co-treatment | SMD (95% CI) at end of treatmenta |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Bergen-Cico (2018) | Control | 48 (34/14) | NR | M = 42, SD = 11.5 | War | Dogs | Dog trainer | Therapeutic dog ownership and training | Waiting for service dog and engaging in social programmes (volunteering in a peer support programme) | NR | PTSD: −0.33 (−0.97 to 0.30) |
| Burton (2019) | Control | 20 (11/9) | 16m/4f | 33–63, M = 47, SD = 14 | War | Horses | Occupational therapist, EAGALA-certified with professional horse handler | Equine- assisted psychotherapy |
Ongoing PTSD therapy | Ongoing PTSD therapy | PTSD: −0.33 (−1.22 to 0.55) |
| Dietz (2012) | Control | 153 (121/32) | 10m/143f | 7–17 | Sexual abuse | Dogs | Licenced and master’s level clinicians (social work, trained psychologists, counselling) | Animal-assisted therapy | Group PTSD therapy | NR | PTSD: −0.31 (−0.70 to 0.08) |
| Johnson (2018) | RCT | 19 (19/13) |
32m/6fb | 29–73, M = 54.35, SD = 12.85 | War | Horses | Occupational therapists and PATH-certified riding instructors | Therapeutic horseback riding | Waitlist | NR | PTSD: −0.82 (−1.56 to −0.08) |
| Mueller (2017) | Control | 54 (25/29) | 45m/9f | 10–18 | Physical, sexual, emotional abuse and neglect | Horses | Licenced clinical social worker | Equine-facilitated psychotherapy | Continuation with trauma-focused cognitive behavioural therapy | NR | PTSD: −0.14 (−0.67 to 0.40) |
| O’Haire (2018) | Control | 141 (75/66) | 110m/31f | M = 37.1, SD = 8.3 | War | Dogs | NA | Service dog | Waiting for service dog; ongoing usual care | Unrestricted access to usual care | PTSD: −0.65 (−0.99 to −0.31) |
| Whittlesey-Jerome (2014) | Control | 13 (6/7) | 0m/13f | 28–64, M = 43.75 | In abusive relationship | Horses | Mental health professional or licenced professional counsellor credentialed by EAGALA | Equine-assisted psychotherapy | Ongoing regular traditional group therapy | Regular traditional group therapy | Depression: −0.32 (−1.42 to 0.78) |
| Woolley (2004) | Control | 21 (11/10) | 11m/10f | 11–17 | Abuse, maltreatment | Farm animals | Staff person or volunteer | Animal-assisted therapy | Conventional psychotherapy | Conventionalpsychotherapy | Depression: −0.03 (−0.88 to 0.83) |
N: number of analysed participants in the study; M: mean; SD: standard deviation; SMD: standard mean difference, CI: confidence interval; NR: not reported; m: male; f: female; NA: not applicable; AAI: animal-assisted intervention; RCT: randomized controlled trial; PTSD: post-traumatic stress disorder; EAGALA: equine-assisted growth and learning association; PATH: Professional Association of Therapeutic Horsemanship; anegative values indicate superiority of AAI over the comparator; bsome studies report gender only for included participants and not for the number of analysed participants.