Comparison 2. Any early psychological intervention versus active control condition.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Dropouts from treatment	2	425	Risk Ratio (M‐H, Random, 95% CI)	1.61 [1.11, 2.34]
1.1 Brief individual trauma processing therapy vs parenting support	1	262	Risk Ratio (M‐H, Random, 95% CI)	1.78 [1.12, 2.84]
1.2 Guided self‐help vs physical educational intervention	1	163	Risk Ratio (M‐H, Random, 95% CI)	1.33 [0.71, 2.50]
2 Severity of PTSD symptoms post‐treatment	2	392	Std. Mean Difference (IV, Random, 95% CI)	0.13 [‐0.06, 0.33]
2.1 Brief individual trauma processing therapy vs parenting support	1	217	Std. Mean Difference (IV, Random, 95% CI)	0.14 [‐0.13, 0.41]
2.2 Guided self‐help vs physical educational intervention	1	175	Std. Mean Difference (IV, Random, 95% CI)	0.13 [‐0.17, 0.42]
3 Severity of PTSD symptoms at 3–6 months	4	465	Std. Mean Difference (IV, Random, 95% CI)	‐0.02 [‐0.31, 0.26]
3.1 Brief individual trauma processing therapy vs supportive listening	2	51	Std. Mean Difference (IV, Random, 95% CI)	‐0.54 [‐1.42, 0.34]
3.2 Brief individual trauma processing therapy vs parenting support	1	239	Std. Mean Difference (IV, Random, 95% CI)	0.06 [‐0.19, 0.31]
3.3 Guided self‐help vs physical educational intervention	1	175	Std. Mean Difference (IV, Random, 95% CI)	0.13 [‐0.16, 0.43]
4 Severity of PTSD symptoms at 7–12 months	1	200	Mean Difference (IV, Random, 95% CI)	1.27 [‐0.60, 3.14]
4.1 Brief individual trauma processing therapy vs parenting support	1	200	Mean Difference (IV, Random, 95% CI)	1.27 [‐0.60, 3.14]
5 Severity of depression symptoms post‐treatment	2	392	Std. Mean Difference (IV, Random, 95% CI)	0.12 [‐0.08, 0.32]
5.1 Brief individual trauma processing therapy vs parenting support	1	217	Std. Mean Difference (IV, Random, 95% CI)	0.06 [‐0.21, 0.33]
5.2 Guided self‐help vs physical educational intervention	1	175	Std. Mean Difference (IV, Random, 95% CI)	0.19 [‐0.11, 0.49]
6 Severity of depressive symptoms at 3–6 months	2	409	Std. Mean Difference (IV, Random, 95% CI)	0.04 [‐0.16, 0.23]
6.1 Brief individual trauma processing therapy vs parenting support	1	234	Std. Mean Difference (IV, Random, 95% CI)	0.09 [‐0.17, 0.34]
6.2 Guided self‐help vs physical educational intervention	1	175	Std. Mean Difference (IV, Random, 95% CI)	‐0.04 [‐0.33, 0.26]
7 Severity of depressive symptoms at 7–12 months	1	198	Mean Difference (IV, Random, 95% CI)	0.79 [‐0.66, 2.24]
7.1 Brief individual trauma processing therapy vs parenting support	1	198	Mean Difference (IV, Random, 95% CI)	0.79 [‐0.66, 2.24]
8 Severity of anxiety symptoms post‐treatment	2	392	Std. Mean Difference (IV, Random, 95% CI)	0.08 [‐0.12, 0.28]
8.1 Brief individual trauma processing therapy vs parenting support	1	217	Std. Mean Difference (IV, Random, 95% CI)	0.10 [‐0.17, 0.37]
8.2 Guided self‐help vs physical educational intervention	1	175	Std. Mean Difference (IV, Random, 95% CI)	0.05 [‐0.24, 0.35]
9 Severity of anxiety symptoms at 3–6 months	2	414	Std. Mean Difference (IV, Random, 95% CI)	0.00 [‐0.19, 0.19]
9.1 Brief individual trauma processing therapy vs parenting support	1	239	Std. Mean Difference (IV, Random, 95% CI)	0.03 [‐0.22, 0.28]
9.2 Guided self‐help vs physical educational intervention	1	175	Std. Mean Difference (IV, Random, 95% CI)	‐0.04 [‐0.33, 0.26]
10 Severity of anxiety symptoms at 7–12 months	1	199	Mean Difference (IV, Random, 95% CI)	‐0.07 [‐1.58, 1.44]
10.1 Brief individual trauma processing therapy vs parenting support	1	199	Mean Difference (IV, Random, 95% CI)	‐0.07 [‐1.58, 1.44]
11 General functioning post‐treatment	1	218	Mean Difference (IV, Random, 95% CI)	‐0.02 [‐0.05, 0.01]
11.1 Brief individual trauma processing therapy vs parenting support	1	218	Mean Difference (IV, Random, 95% CI)	‐0.02 [‐0.05, 0.01]
12 General functioning at 3–6 months	1	239	Mean Difference (IV, Random, 95% CI)	‐0.03 [‐0.06, 0.00]
12.1 Brief individual trauma processing therapy vs parenting support	1	239	Mean Difference (IV, Random, 95% CI)	‐0.03 [‐0.06, 0.00]
13 General functioning at 7–12 months	1	199	Mean Difference (IV, Random, 95% CI)	0.01 [‐0.03, 0.05]
13.1 Brief individual trauma processing therapy vs parenting support	1	199	Mean Difference (IV, Random, 95% CI)	0.01 [‐0.03, 0.05]