“…Dementia and depression are among the most frequent psychiatric diseases in old age (Hegerl, Zaudig, & Möller, 2001). However, data on comorbidity of dementia and depression are strikingly heterogeneous and differ widely depending on the study design and method (Hautzinger, 2000;Kales, Chen, Blow, Welsch, & Mellow, 2005). Wetzels, Zuidema, de Jonghe, Verhey, and Koopmans (2010) showed that approximately one fourth of all nursing-home residents with dementia developed symptoms of depression within a period of 2 years.…”