Depression raises dementia risk in men

Men with a history of depression before the onset of any memory or cognitive problems have a higher risk of developing dementia, especially Alzheimer's disease (AD), later in life. Researchers from the University Campus BioMedico and Associazione Fatebenefratelli per la Ricerca, Rome, Italy, examined the association between premorbid symptoms of depression and the development of dementia and AD over a period of 14 years in 1357 subjects. Researchers assessed the frequency and severity of depressive symptoms every 2 years using standard instruments. A total of 49 cases of dementia were diagnosed among women during the study period. Of these, 40 represented AD. A total of 76 men were diagnosed with dementia, of which 67 represented AD.

The risk of dementia, especially AD, was significantly increased with premorbid depressive symptoms only in men. The risk was approximately two times greater in those with a history of depression as compared to those without a history of depression. The prevalence and clinical manifestations of both AD and depression differ in men and women. Male and female brains have anatomical and functional differences and are exposed differently to sex hormones throughout life, hormones known to have effects on both depression and AD. As a consequence, male and female brains might react to conditions causing or enhancing a disease quite differently.

Given the prevalence of depression and increasing longevity worldwide, clearly the public health and economic implications are significant.
Prevention of depressive disorders and aggressive as well as long-term treatment of depression may impact on the epidemiology of dementia. This is particularly relevant in men since they generally are less likely to admit to symptoms of depression and to seek treatment.