A total of 40 RCTs (n=6,391) were eligible for inclusion in the meta-analysis: 38/40 RCTs were double-blinded; 39/40 were rated B for allocation concealment (inadequate details how the randomisation procedure was carried out).
There was no significant effect of paroxetine versus placebo on the proportion of patients discontinuing treatment for any reason (40 RCTs; RR 0.99, 99%CI: 0.88, 1.11). Between-study heterogeneity was not significant (I2 = 21 per cent).
Significantly fewer patients receiving paroxetine did not receive at least 50 per cent improvement in symptoms (22 RCTs; RR 0.83, 99% CI: 0.77, 0.90). Between study heterogeneity was not significant (I2 = 19.2 per cent). An improvement for paroxetine was also observed in terms of standardised depression outcomes (34 RCTs; SMD -0.31, 99% CI: -0.40, -0.22). Between-study heterogeneity was not significant (I2 = 31.5 per cent).
Significantly more patients treated with paroxetine withdrew because of side effects (38 RCTs; RR 1.77, 95% CI: 1.44, 2.18). Between-study heterogeneity was not significant (I2 = 2 per cent).
Significantly more adverse events were reported for paroxetine than placebo (35 RCTs; RR 1.15, 95% CI: 1.11, 1.19). Between-study heterogeneity was not significant (I2 = 17.6 per cent).
There was no significant difference in serious adverse events between groups (34 RCTs; Peto OR 1.27, 95% CI: 0.88, 1.83). There was no significant between-study heterogeneity (I2 = 0 per cent).
Suicidal tendencies were significantly more frequently reported for paroxetine than for placebo (15 RCTs; Peto OR 2.55, 95% CI: 1.17, 5.54). There was no significant between-study heterogeneity (I2 = 0 per cent).