A Cochrane review included 14 studies with a total of 590 participants. No overall difference was found for the primary outcome of response to treatment compared with placebo RR 1.07, 95% CI 0.91 to 1.26; 9 trials, N = 454). Treatment with a tricyclic antidepressant caused more vertigo (RR 2.76, 95% CI 1.73 to 4.43; 5 trials, N = 324), orthostatic hypotension (RR 4.86, 95% CI 1.69 to 13.97; 5 trials, N = 324), tremor (RR 5.43, 95% CI 1.64 to 17.98; 4 trials, N = 308) and dry mouth (RR 3.35, 95% CI 1.98 to 5.64; 5 trials, N = 324) than did placebo,
Pooled odds ratio calculated from the dichotomous data showed no advantage over placebo (OR 0.84, 95% CI 0.56 to 1.25; 9 trials). A statistically significant but small benefit of treatment over placebo was seen in reducing symptoms (SMD –0.31, 95% CI –0.62 to –0.01). Subgroup analyses suggested a larger benefit among adolescents (effect size = –0.47, 95% CI –0.92 to –0.02), and no benefit among children (effect size = 0.15, 95% confidence interval –0.34 to 0.64). Tricyclic antidepressants were associated with more adverse events like vertigo, orthostatic hypotension, tremor and dry mouth compared to placebo. Another systematic review