that gene influences the phenotype (Geschwind & Flint, 2015, Mackay et al., 2009). For example, one could test whether genetic markers identified as associated with alcohol dependence influence a person’s biological or subjective response to alcohol or whether they influence sensitivity to reward more broadly. Understanding the different biological and environmental mechanisms underlying complex behavioral traits should help us refine where personalized prevention/treatment efforts can be developed to target the underlying cause of a disorder, which may differ greatly between two individuals with the same symptoms or diagnosis.
