Comparison 2. Anticonvulsants versus placebo.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
2.1 Clinical Global Impressions Scale Improvement Item (CGI‐I)	4		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
2.1.1 No. of responders	4	315	Risk Ratio (M‐H, Random, 95% CI)	0.87 [0.63, 1.21]
2.2 Dropout rate due to treatment emergent adverse effects	5		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
2.2.1 Dropout rate	5	348	Risk Ratio (M‐H, Random, 95% CI)	0.98 [0.92, 1.05]
2.3 Clinically Administered PTSD Scale (CAPS): reduction of PTSD symptoms	5		Mean Difference (IV, Random, 95% CI)	Subtotals only
2.3.1 CAPS: Total score	5	411	Mean Difference (IV, Random, 95% CI)	‐0.35 [‐6.54, 5.84]
2.3.2 CAPS subscale: Re‐experiencing/intrusion	3	141	Mean Difference (IV, Random, 95% CI)	0.20 [‐3.74, 4.13]
2.3.3 CAPS subscale: Avoidance/numbing	3	141	Mean Difference (IV, Random, 95% CI)	‐0.37 [‐8.65, 7.91]
2.3.4 CAPS subscale: Hyperarousal	3	141	Mean Difference (IV, Random, 95% CI)	0.21 [‐2.57, 2.99]
2.4 Symptom severity: Other measures	5		Std. Mean Difference (IV, Random, 95% CI)	Subtotals only
2.4.1 Reduction of PTSD symptoms	5	180	Std. Mean Difference (IV, Random, 95% CI)	0.15 [‐0.31, 0.60]
2.5 Self‐rated scales	3		Std. Mean Difference (IV, Random, 95% CI)	Subtotals only
2.5.1 Reduction of PTSD symptoms	3	84	Std. Mean Difference (IV, Random, 95% CI)	‐0.06 [‐0.75, 0.64]
2.6 Depression scale (typically Hamilton Depression)	5		Std. Mean Difference (IV, Random, 95% CI)	Subtotals only
2.6.1 Reduction of depression symptoms	3	131	Std. Mean Difference (IV, Random, 95% CI)	‐0.22 [‐0.57, 0.12]
2.6.2 Depression Scale ‐ Change scores	2	66	Std. Mean Difference (IV, Random, 95% CI)	‐0.32 [‐0.81, 0.16]
2.7 Anxiety ‐ Hamilton Anxiety Scale	3		Mean Difference (IV, Random, 95% CI)	Subtotals only
2.7.1 Reduction of anxiety symptoms	3	138	Mean Difference (IV, Random, 95% CI)	‐0.66 [‐3.66, 2.35]
2.8 Anxiety ‐ Other scales	1		Std. Mean Difference (IV, Random, 95% CI)	Subtotals only
2.8.1 Reduction of anxiety symptoms	1	28	Std. Mean Difference (IV, Random, 95% CI)	0.55 [‐0.21, 1.31]
2.9 Sheehan Disability Scale	2		Mean Difference (IV, Random, 95% CI)	Subtotals only
2.9.1 Reduction of functional disability	2	270	Mean Difference (IV, Random, 95% CI)	0.41 [‐1.48, 2.30]
2.10 Dropout rate due to any cause	7		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
2.10.1 Dropout rate	7	447	Risk Ratio (M‐H, Random, 95% CI)	0.80 [0.61, 1.06]