Depression in Alzheimer’s Disease: The Roles of Cholinergic and Serotonergic Systems

ABSTRACT

Although depression and Alzheimer’s disease fundamentally result from distinct pathophysiological events, their coincidence is far from a rare occurrence. In addition to the difficulty in the diagnosis of depression in the patients with a cognitive impairment, care givers and even physicians are mostly unaware that depression and Alzheimer’s disease can coexist. While depression has already a devastating impact on quality of life by itself, coinciding depression and Alzheimer’s disease may advance to a cataclysmic magnitude. This chapter underlines obstacles in the recognition of depression in the Alzheimer’s patients following a brief introduction to the concept of depression. Depression and Alzheimer’s disease appear to intersect in the cholinergic and serotonergic systems which may engender an exquisite strategy in the treatment of both disorders. Therefore, potential cholinergic and serotonergic targets are also emphasized.