This thesis address two of the most common psychiatric illnesses in the population world wide, namely Unipolar Major Depression (MDD), and the frequent co-occurrence of anxiety disorder (A). The high rates of both MDD and anxiety disorders in the population make the study of the co-occurrence of these two disorders highly relevant both for clinicians and the society. The presence of co-morbid anxiety disorders in persons with MDD has largely gone unexamined, especially regarding the effects on neuropsychological functioning. Both disorders are associated with cognitive deficits, but separate...