2009. World Federation of Societies of Biological Psychiatry (WFSBP) Guidelines for biological treatment of unipolar depressive disorders, part 2: maintenance treatment of major depressive disorder and treatment of chronic depressive disorders and subthreshold depressions . Archives of Clinical Psychiatry. 36, supl.2 (Jan. 2009), 58–76. DOI:https://doi.org/10.1590/S0101-60832009000800002.