The indirect evidence comes from studies showing strong links between physical health and mental disorders that are themselves strongly linked with neuroticism, particularly depression and anxiety disorders. A wide range of physical health problems are more common among individuals with mood and anxiety disorders, which are strongly correlated with neuroticism (Currie & Wang, 2005; Robles, Glaser, & Kiecolt-Glaser, 2005; Sareen, Cox, Clara, & Asmundson, 2005; Watkins et al., 2006). Depression and anxiety disorders are associated with disrupted immune functioning (Maier & Watkins, 1998; Pace et al., 2006; Robles et al., 2005), abnormalities in cardiac functioning (Barger & Sydeman, 2005), and increased mortality among individuals with other risk factors for cardiac disease (Penninx et al., 2001; Robles et al., 2005; Simonsick, Wallace, Blaser, & Gerkman, 1995). Again, however, the literature on anxiety and depression only provides indirect evidence regarding the association of neuroticism with physical health problems that is subject to multiple interpretations.
