Placebo response for each symptom domain by age group
| Symptom domain | Children/adolescents | Adolescents | Adults | Adults/elderly | Elderly | |||||
| o/k (n) | SMD (95% CI) | o/k (n) | SMD (95% CI) | o/k (n) | SMD (95% CI) | o/k (n) | SMD (95% CI) | o/k (n) | SMD (95% CI) | |
| Aggregate | 44/17 (1095) | −1.14 (−1.42 to −0.87) | 2/2 (36) | −1.16 (−2.25 to −0.07) | 152/58 (4669) | −1.11 (−1.29 to −0.92) | 165/55 (6533) | −1.11 (−1.28 to −0.95) | 5/3 (250) | −1.28 (−2.09 to −0.47) |
| GAD | 12/6 (333) | −1.35 (−1.93 to −0.78) | 2/2 (36) | −1.16 (−2.25 to −0.07) | 33/25 (2688) | −1.30 (−1.65 to −0.95) | 53/33 (4036) | −1.25 (−1.48 to −1.02) | 5/3 (250) | −1.28 (−2.09 to −0.47) |
| Social anxiety | 5/2 (305) | −1.17 (−2.01 to −0.32) | – | – | 25/14 (893) | −0.85 (−1.08 to −0.62) | 19/12 (1701) | −0.85 (−0.98 to −0.72) | – | – |
| Panic | – | – | – | – | 12/7 (865) | −0.67 (−0.90 to −0.44) | 23/11 (896) | −0.53 (−0.93 to −0.14) | – | – |
| Specific phobias | – | – | – | – | 8/6 (754) | −0.74 (−1.17 to −0.31) | 9/5 (456) | −0.58 (−0.68 to −0.48) | – | – |
| PTSD | 2/1 (62) | −1.91 (−2.35 to −1.48) | – | – | 21/10 (283) | −1.77 (−2.5 to −1.02) | 20/9 (849) | −1.45 (−2.09 to −0.80) | – | – |
| OCD | 15/8 (367) | −0.80 (−0.9 to −0.69) | – | – | 21/11 (784) | −0.70 (−0.98 to −0.41) | 7/3 (229) | −0.79 (−1.35 to −0.22) | – | – |
‘Aggregate’ refers to the aggregate measure of all internalising symptoms.
GAD, generalised anxiety disorder; k, number of studies; n, sample size; o, number of outcomes; OCD, obsessive-compulsive disorder; PTSD, post-traumatic stress disorder; SMD, standardised mean difference.