Effectiveness of maintenance therapy of lithium vs other mood stabilizers in monotherapy and in combinations: a systematic review of evidence from observational studies.

The results show the superiority in real life of lithium monotherapy compared with monotherapy with other maintenance mood stabilizers. The four largest register-based studies largely addressed confounding, but, as ever, residual confounding cannot be excluded. Nevertheless, the observational findings substantially add to the findings from randomized controlled trials, whose designs often limit the validity of comparison between medicines.