Monoamine (neurotransmitters/hormones such as dopamine, serotonin and noradrenaline) transporters are also implicated in the treatment of depression and anxiety, with SSRIs targeting the serotonin transporter (SERT), serotonin noradrenaline reuptake inhibits (SNRIs) targeting both SERT and the noradrenaline transporter (NET) and triple uptake inhibitors targeting all three transporters, preventing the uptake of serotonin, dopamine and noradrenaline into the cell (Lucki and O'Leary, 2004; Zhou, 2004). This evidence concerns the gene SLC6A4 and major depressive disorder.