Letter of response to Nabi Z, Stansfeld J, Plöderl M, Wood L, Moncrieff J. Effects of lithium on suicide and suicidal behaviour: a systematic review and meta-analysis of randomised trials. Epidemiol Psychiatr Sci. 2022 Sep 16;31:e65. doi: 10.1017/S204579602200049X

Since the outcome of a meta-analysis depends on which studies are included (Walker et al., 2008), the reasons for the discrepancy between the findings of Nabi et al. and previous meta-analyses may depend on the seemingly arbitrary inclusion and exclusion of randomised controlled trials (RCTs) and on an unsatisfactory reinterpretation of data compared to the original publications. [...]more RCTs were excluded (N = 15) from the primary analysis than those included (N = 12). [...]in a meta-analysis of 31 studies with a total of over 85 000 person-years of risk exposure, Baldessarini et al.