Despite numerous studies the relationship between depression and Alzheimer’s disease has not yet been clarified. The high prevalence of depression in Alzheimer’s disease has been confirmed but the data on its incidence vary. Generally, depressed mood is the most prevalent symptom in 0-86% of dementia syndrome, minor depression, dysthymia is considered to be present in 20-30% of patients and major depression is least frequent.
It seems confirmed that depression may be considered to be a risk factor for dementia, but the coincidence of these two diseases remains still unknown. Since the symptoms of depression and dementia are very similar, the clinical picture brings other controversies. Loss of energy, speech paucity, poor attention and concentration, diminished interest and psychomotor slowness cannot differentiate dementia from depression, the disability level seems to be the only differentiating factor. Depression may be suspected in case of changes in functional level, complaints about pain and diurnal variation of symptoms. From the practical point of view the type of contact and the willingness of perform tests are among the crucial symptoms. Sometimes, it is difficult to separate apathy and pathological crying from depression.
The pathomechanism of depression in dementia is not known. The role of serotoninergic and cholinergic transmission changes, alterations of glucocorticoid cascade and presence of apoE are considered but without evident results.
Source: Neurol Neurochir Pol 1999;33 Suppl 1:39-50
PMID: 10404520, UI: 99332599