While patients suffering from depression and anxiety will not possess every SNP, transcript or protein change, we speculate that any of these changes could result in decreased endocytosis of 5-HT1A and 5-HT2A, disrupting their typical plasma membrane and endosomal signaling profiles (Figure 3A), or enhance clathrin-independent endocytosis and recycling of SERT or decrease SERT CME, increasing its levels at the plasma membrane (Figure 3B), which would deplete extracellular serotonin levels to further reducing serotonin signaling. This evidence concerns the gene SLC6A4 and depressive disorder.