The study confirmed pathways that have been related to depression, such as neurotrophin, mTOR, PI3K/Akt, RAS/RAF/MAPK/ERK, and stem cells pluripotency regulating pathways, and presented others that have not been often related to depression, such as the endoplasmic reticulum protein-processing pathway and the focal adhesion pathway. This evidence concerns the gene PIK3CA and depressive symptom measurement.