Caveat emptor: Folate in unipolar depressive illness, a systematic review and meta-analysis.

Whilst previous guidelines on the treatment of unipolar depression have either avoided this topic entirely, or made recommendations on the basis of cherry-picked evidence, this review is the first to attempt to provide clinically useful recommendations based on comprehensive, current randomised placebo-controlled data. We invite discussion of the review and its recommendations, which are based on the limited evidence regarding folate formulation delivered and appropriate dosage.