Twenty-one RCTs with 1,805 participants were included in the review.
SSRIs in OCD (8 RCTs).
Three RCTs compared fluoxetine with placebo and found effect sizes ranging from 0.2 to 0.6 in favour of fluoxetine. One large RCT found that fluvoxamine was more effective than placebo, with an effect size of 0.3. Two large RCTs found that paroxetine was more effective than placebo (effect sizes or NNTs not reported). Two RCTs compared sertraline with placebo: one reported an NNT of 6, the other found that CBT combined with sertraline was superior to either treatment alone, all treatment options being superior to placebo (effect sizes: sertraline 0.67, CBT 0.97, combination 1.4).
TCAs in OCD (3 RCTs).
Three small RCTs compared clomipramine with placebo and found, respectively, effect sizes of 0.8 and 0.97 and an NNT of 4.
SSRIs in other anxiety disorders (5 RCTs).
Two RCTs assessed SSRIs for anxiety disorders in general. One found that fluvoxamine was more effective than placebo in treating children with SAD, GAD or SP (effect size 1.1, NNT 2). The other RCT found a similar result in the same population when comparing fluoxetine with placebo (effect size 0.4, NNT 4). One small RCT assessed sertraline for GAD and found an effect size of 1.9 and an NNT of 1. A large RCT assessed paroxetine for SP and found an NNT of 3. A final small RCT assessed fluoxetine for elective mutism and found an effect size of 0.67.
TCAs in other anxiety disorders (5 RCTs).
Three small RCTs compared imipramine with placebo; two showed effectiveness for, respectively, school phobia (NNT 3) and school refusal in conjunction with at least one anxiety disorder (effect size 0.3, NNT 3; treatment combined with CBT). The third found little evidence of effectiveness (NNT 100). One RCT found no evidence of effectiveness for imipramine combined with alprazolam for school phobia and related anxiety, and another no significant difference from placebo or clomipramine in the treatment of school phobia.
Side-effects were also reported.