Although this study shows that neuroticism is common to mood and anxiety disorders, it is possible that studies that measure other traits in addition to neuroticism would yield different results. Future research should focus on other constructs that may be common to mood and anxiety disorders, including emotion regulation and rumination. Emotion regulation refers to biological and psychological processes that influence how emotions are expressed or experienced (Gross, 2002). It is possible that individual differences in emotion regulation predispose people to depression and anxiety, and therefore contribute to their covariation. Rumination is the tendency to repetitively think about negative emotions. Nolen-Hoeksema (2000) found that rumination predicted symptoms of depression and anxiety, as well as the onset of depressive episodes. Some researchers have examined neuroticism, depression, and rumination in the same sample (e.g., Bagby & Parker, 2001), but it is unclear whether rumination also predicts anxiety disorders and whether rumination is especially characteristic of individuals with comorbid mood and anxiety disorders.
