The present invention provides methods for treating depression such as major depressive disorder (MDD) in an individual. The invention further provides methods for determining if an individual suffering from depression is likely to respond favorably or experience an enhanced treatment effect in response to treatment with vortioxetine. The present invention also provides methods for treating cognitive impairment in an individual, optionally wherein the individual also suffers from depression and/or MDD. The invention further provides methods for determining if an individual suffering from cognitive impairment is likely to respond favorably or experience an enhanced treatment effect in response to treatment with vortioxetine. The methods comprise determining the presence of polymorphisms in the collagen, type XXVI, alpha 1 (COL26A1) gene and/or the calcium channel, voltage-dependent, L type, alpha 1C subunit (CACNA1C) gene and/or the CUB and Sushi Multiple Domains 1 (CSMD1) gene and/or the Zinc Finger Protein 494 (ZSCAN4) gene and/or the Zinc Finger Protein 551 (ZNF551) gene and/or the dymeclin (DYM) gene and/or the LINC00348 gene and/or the FOXL2NB gene and/or intergenic regions in the individual.
