The occurrence of depressive symptoms in the preclinical phase of AD - A population-based study

Objective: To examine preclinical depressive symptoms 3 years before the di agnosis of AD. Methods: The authors compared incident AD patients and nonde mented individuals in terms of baseline mood- and motivation-related sympto ms of depression, and assessed whether depressive symptoms in preclinical A D are related to self-perceived memory problems. Participants came from a p opulation-based longitudinal study on aging and dementia in Stockholm, Swed en. The sample consisted of 222 persons older than 74 years who were follow ed for a 3-year interval. Thirty-four individuals had developed AD at follo w-up, whereas 188 remained nondemented. Dementia diagnosis was made accordi ng to the criteria of the Diagnostic and Statistical Manual of Mental Disor ders, 3rd edition, revised. Depressive symptoms were assessed by the Compre hensive Psychopathological Rating Scale. Results: The incident AD patients had more depressive symptoms than the nondemented persons at baseline. Ther e was a dominance of motivation-related symptoms of depression (e.g., lack of interest, loss of energy, concentration difficulties) in preclinical AD. This association remained when adjusting for subjective memory complaints. Conclusions: Depressive symptoms are elevated preclinically in AD, and thi s elevation is not merely a by-product of self-perceived cognitive difficul ties. Thus, depressive symptoms may be part of the preclinical phase in AD.