As the elderly population is growing, mental diseases, particularly dementia and depression are assumed to be the primary diseases that health professionals are going to deal with. Depressive expressions of variable intensity may be observed in approximately 50% of dementia patients. This review aims to determine whether antidepressants are clinically effective and satisfactory for the treatment of patients diagnosed as having depression and also diagnosed as having dementia. Etiology, diagnosis, natural progression, impact on caregivers or efficacy of any treatment for depression in dementia, and also its diversity and prognosis in other types of dementia is not fully understood. As a conclusion; various antidepressant drugs have been used for treatment of dementia. There is rare data on how to use antidepressants in dementia patients with depression. However, keeping their drug interactions in mind, we believe that use of SSRIs together with non-pharmacologic measures will be beneficial to prevent capacity loss in depressive dementia patients. However further investigation into the prevalence, diagnosis, etiology and treatment of depression among dementia patients at end of life is necessary.