in humans (Shioe et al., 2003; Willeit et al., 2000). The 5-HTTLPR has been linked to alcohol abuse, schizophrenia, depression, bipolar disorder, and smoking, though with inconsistent results (Serretti, Calati, Mandelli, & De, 2006). Based on the literature, it seems that individuals with extremely high or extremely low serotonin levels may be at risk for affective disorders, alcoholism, anxiety disorders, and personality characteristics such as neuroticism (Lesch & Mossner, 1998; Serretti et al., 2006; Gonda et al., 2009; Murphy et al., 2008).
