Mood disorders, especially those related to depression, are among the most prevalent mental impairments. Therefore, understanding their etiology is important for prevention and improving therapy. Sub-clinical depressive symptoms, which predict the onset of mood and anxiety disorders (Gentil et al., 2007), are correlated with slow information processing, poor memory functioning (Simons et al., 2009) and cardiovascular dysfunction (Taillard et al., 1993; Wassertheil-Smoller et al., 2004 ).