et al., 2008a; Enoch, 2013). For example, the short allele of the polymorphic promoter region of the serotonin transporter gene (5-HTTLPR) was associated with more frequent drinking as well as heavy drinking and drug use in college students if they had also experienced multiple negative life events in the past year (Covault et al., 2007). The serotonin transporter (SLC6A4, also known as 5-HTT or SERT) is responsible for serotonin reuptake from the synaptic cleft (Heils et al., 1996). Alleles in 5-HTTLPR alter SLC6A4 production, which may influence function of the glucocorticoid receptor as well as HPA axis activity.
