Table 2.
Reported effects on PTSD symptoms and risk of bias.
| Study (Author, year) | Type of trauma | Dropout | Results NF Group | Results Control Group | Between Group Difference Pre-Post/Length of follow up | Remission Rate | Risk of Bias | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| rp | dii | md | Mo | srr | o | |||||||
| Peniston & Kulkosky, 1991 | Combat PTSD | NF: 0/15 | Pre: 30.6 ± 9.1 | Pre: 35.9 ± 7.2 | Δ – 20.4, p < .05 MMPI PTSD subscale; 30 months follow up | NF: 80% | - | + | + | + – | + | - |
| CL: 0/14 | Post: 10.5 ± 6.2 | Post: 36.2 ± 5.3 | Cl: 0% | |||||||||
| Δ – 20.1 (−66%) | Δ + 0.3 (1%) | p < .05 between groups | ||||||||||
| Kelson, 2013 | Combat PTSD | NF: 0/5 | Pre: 72.8 ± 12.6 | Pre: 69.4 ± 10.0 | Δ – 38.0, p < .01 | NF: 100% | + | - | - | - | + | - |
| CL: 0/5 | Post: 44.2 ± 9.6 | Post: 78.8 ± 9.0 | Non-validated PTSD questionnaire; | CI: 0% | ||||||||
| Δ – 28.6 (−39%) | Δ + 9.4 (12%) | No follow up | ||||||||||
| van der Kolk et al., 2016 | Multiple treatment resistant traumas (developmental trauma and domestic violence) | NF: 6/28 | Pre: 79.5 ± 16.9 | Pre: 76.2 ± 16.9 | Δ – 26.8, p < .001 | NF: 73% Cl: 32% p = .007 |
+ | + | + | + | + | + |
| CL: 2/24 | Post: 43.0 ± 20.2 | Post: 66.5 ± 20.6 | CAPS-4; | |||||||||
| Δ – 36.5 (−46%) | Δ – 9.7 (−13%) | 30 days follow up | ||||||||||
| Pre: 67.3 ± 9.7 | Pre: 63.0 ± 10.5 | Δ – 18.3, p < .001 | ||||||||||
| Post: 44.2 ± 8.4 | Post: 58.2 ± 8.9 | DTS; | ||||||||||
| Δ – 23.1 (−34%) | Δ – 4.8 (−8%) | 30 days follow up | ||||||||||
| Noohi et al., 2017 | Combat PTSD | NF: 0/15 | Pre: 47.2 ± 7.6 | Pre: 51.1 ± 5.4 | Δ – 16.8, p < .001 | Not reported | + – | - | - | - | + | - |
| CL: 0/15 | Post: 30.4 ± 6.2 | Post: 51.1 ± 6.2 | IES-R; | |||||||||
| Δ – 16.8 (−36%) | Δ 0.0 (0%) | 43 days follow up | ||||||||||
| Bell et al., 2019 | Combat PTSD | NF: 0/12 | Pre: 46.17 ± 14.23 | Pre: 49.82 ± 10.16 | Δ – 9.45, p > .5 | Not reported | - | + | + | + | + | - |
| Cl: 1/11 | Post: 18.08 ± 12.65 | Post: 31.18 ± 13.53 | PCL-5; | |||||||||
| Δ – 28.09 (−61%) | Δ – 18.64 (−37%) | No follow up | ||||||||||
| Nicholson, Ros, Jetly, et al., 2020 | Mixed treatment resistant trauma (developmental, military, first responders) | NF: 0/18 | Pre: 36.8 ± 10.3 | Pre: 39.94 ± 7.83 | Δ – 5.3, | NF: 61.1% Cl: 33.3% p = .040 |
+ | + | + | + | + | + |
| CL:0/18 | Post: 24.3 ± 15.6 | Post: 32.78 ± 12.27 | CAPS-5; | |||||||||
| Δ – 12.5 (−34%) | Δ – 7.2 (−18%) | 3 months follow up | ||||||||||
| Askovic et al., 2020 | Refugee and war trauma | NF: 0/13 | Pre: 2.8 ± 0.4 | Pre: 3.2 ± 0.5 | Δ – 0.8, p > .002 | NF: 92% Cl: 8% |
- | + | ? | - | + | - |
| CL: 0/13 | Post:1.9 ± 0.5 | Post: 3.1 ± 0.6 | HTQ-16; | |||||||||
| Δ −0.9 (−32%) | Δ −0.1 (−3%) | No follow up | ||||||||||
| Leem et al., 2021 | Mixed trauma: domestic violence (16), traffic accidents (2), school violence (1) | NF: 1/11 | Pre: 44.3 ± 10.8 | Pre: 35.1 ± 18.5 | Δ – 20.8, p < .01 | Not reported | + | + | - | + | + | - |
| Cl: 2/11 | Post: 19.4 ± 7.8 | Post: 31.0 ± 14.9 | PCL-5-K; | |||||||||
| Δ – 24.9 (−56%) | Δ – 4.1 (−12%) | 30 days follow up | ||||||||||
| Pre: 47.5 ± 16.8 | Pre: 34.6 ± 16.9 | Δ – 18.4 p < .05 | ||||||||||
| Post: 25.6 ± 10.5 | Post: 31.1 ± 16.6 | IES-R-K; | ||||||||||
| Δ – 21.9 (−46%) | Δ – 3.5 (−10%) | 30 days follow up | ||||||||||
| du Bois et al., 2021 | Victims of genocide | NF: 0/10 | Pre: 38.9 ± 16.7 | Pre: 34.4 ± 23.8 | Δ – 22.2, p < .01 | NF: 70% CL: not reported |
- | + | + | +- | + | - |
| CL: 0/10 | Δ – 27.9 (−72%) | Δ – 5.7 (−17%) | No follow up | |||||||||
| Post: 11.0 ± 5.5 | Post: 28.7 ± 20.1 | PCL-5; | ||||||||||
| Pre: 2.2 ± 0.5 | Pre: 2.1 ± 0.7 | Δ – 0.7, p < .01 | ||||||||||
| Post: 1.3 ± 0.2 | Post: 1.9 ± 0.6 | HTQ; | ||||||||||
| Δ – 0.9 (−41%) | Δ – 0.2 (−10%) | No follow up | ||||||||||
| Pre: 3.2 ± 1.1 | Pre: 3.0 ± 1.7 | Δ – 2.3, p < .01 | ||||||||||
| Post: 0.3 ± 0.7 | Post: 2.4 ± 2.0 | PC-PTSD; | ||||||||||
| Δ – 2.9 (−94%) | Δ – 0.6 (−20%) | No follow up | ||||||||||
| Winkeler et al., 2022 | Multiple traumas with first trauma happened in childhood (sexual, physical and emotional abuse, neglect) | NF: 0/18 | Pre: 11.1 ± 0.6 | Pre: 11.2 ± 0.7 | Δ – 0.6, p = .05 | NF: not reported Cl: not reported |
+ | + | + | +- | + | +- |
| CL: 2/18 | Post: 10.3 ± 1.0 | Post: 11.0 ± 1.1 | PCL-5; | |||||||||
| Δ – 0.8 (−7%) | Δ – 0.2 (−2%) | No follow up | ||||||||||
Abbreviations: PTSD, posttraumatic stress disorder; N.F., neurofeedback; CI, control intervention; Δ, difference; A negative between-group difference in change indicates a difference in favour of neurofeedback; MMPI, Minnesota Multiphasic Personality Inventory; CAPS, Clinician Administered PTSD Scale; intervention; IES-R, Impact of Event Scale-Revised;. PCL, PTSD Checklist; HTQ, Harvard Trauma Questionnaire; rp, randomisation process; dii, deviation from intended intervention; md, missing outcome data; mo, measurement of the outcome; srr, selection of the reported result; o, overall risk of bias; –,high risk of bias; +, low risk of bias; + -, some concerns of bias.