The specificity of depressive symptoms in patients with Alzheimer's disease

Objective: This study assessed the specificity of depressive symptoms in pa tients with Alzheimer's disease and examined the discrepancies between pati ent and caregiver symptom reports. Method: The study group was composed of a series of 233 patients with Alzhe imer's disease, 47 patients with depression but without dementia, and 20 he althy comparison subjects; the latter two groups were comparable in age wit h the patients with Alzheimer's disease. The patients and comparison subjec ts received a comprehensive psychiatric evaluation, which included administ ration of the Hamilton Depression Rating Scale and the Structured Clinical Interview for DSM-IV. Results: Patients with Alzheimer's disease with a score of 2 or higher on t he "depressed mood" item of the Hamilton depression scale, as scored by the ir respective caregivers, comprised a group with depressed mood (N = 92), w hereas patients who scored 0 on this item comprised a group without depress ed mood (N = 62). A statistical comparison of the scores on the remaining H amilton depression scale items (2-16) between the Alzheimer's disease patie nts with and without depressed mood revealed significant differences on all items, except "loss of appetite." However, there were no significant diffe rences on any single Hamilton depression scale item between the Alzheimer's disease patients without depressed mood and the age-comparable healthy com parison subjects. Conclusions: Depressive symptoms are not widespread among patients with Alz heimer's disease but are significantly related to an underlying depressed m ood. Patients with Alzheimer's disease may not be fully aware of the extent of their depressive symptoms.