“…Specifically, an external locus of control (i.e., a tendency to attribute consequences and events to external factors such as luck, other people, or uncontrollable forces) has been associated with (1) a reduced anticipation that a specific behavior will lead to a reward (e.g., Rotter, 1966); (2) increased psychological and biological stress reactivity (e.g., Bollini, Walker, Hamann, & Kestler, 2004;Kobasa, 1979); and (3) dysregulation of plasma concentrations of dopamine metabolites (De Brabander & Declerk, 2004). These findings suggest that individuals characterized by low perception of control are less responsive to rewards and more sensitive to stressors, possibly due to subtle differences in the mesolimic dopamine reward system (Declerck, Boone, & De Brabander, 2006). Third, individuals suffering from melancholic depression, a subtype of depression characterized by anhedonic features, often show hypercortisolemia (Gold & Chrousos, 1999;Ehlert et al, 2001;Gold & Chrousos, 2002) and report higher levels of subjective severity, but not number, of minor daily stressors compared to control individuals and individuals with nonmelancholic depression (Willner, Wilkes & Orwin, 1990).…”