In addition, the time is right to invest in a better understanding of the genetic and environmental factors that influence neuroticism and play a role in linking it to adverse outcomes. Current evidence strongly suggests that many of the genes influencing neuroticism function as pleiotropic general risk genes that also influence risk for many different mental disorders (Hettema, Neale et al., 2006; Jang & Livesley, 1999) and many different physical health problems (Johnson & Krueger, 2005; McCaffery et al., 2006). Therefore, identifying the genes associated with neuroticism and their interplay with environmental factors should be a top priority for both mental and physical health research. A plausible working model for future studies is that that the etiology of each mental and physical health disorder results from the combined interplay of general-risk genes and environments and disorder-specific genes and environments (Gillespie et al., 2004; Khan et al., 2005; Lahey & Waldman, 2003). To fully understand the etiology of each disorder, it will be necessary to identify each of these factors and how they work together. Understanding the causal pathways linking neuroticism
