An Argentine research team has found evidence of a possible trigger factor for the onset of Alzheimer's disease: stress. Dr Edgardo Reich (Buenos Aires) presented a study on the subject at the XXI World Congress of Neurology in Vienna.

118 patients with diagnosis of Alzheimer's disease were examined, their average age was 73. An average of 2.4 years had passed between this diagnosis and the onset of symptoms. The group of Alzheimer's patients was compared to a control group of 81 healthy individuals whose age, gender distribution and educational level corresponded to the Alzheimer's group. Both groups - or family members and caregivers - were asked whether they had encountered particular stresses and strains in the three years prior to the diagnosis of Alzheimer's.

"Nearly three out of four Alzheimer's patients (72%) had to cope with severe emotional stress - three times as many as the control group in which only 26% experienced stress, grief and sorrow during the preceding 2.1 years before the onset of symptoms," said Dr Reich. Most burdens involved the death of a spouse or partner (24 cases), death of a child (15 cases), violent experiences such as physical assault or robbery (21 cases) or car accidents (11 cases). Also among the stress-factors leading to illness were financial problems, "pension shock", migration-related adaptive changes, bereavement or a diagnosis of a family member's severe sickness.

"Stress, according to our findings, is probably a trigger for initial symptoms of dementia. Though I rule out stress as monocausal in dementia, research is solidifying the evidence that stress can trigger a degenerative process in the brain and precipitate dysfunction in the neuroendocrine and immune system," said Dr Reich. "It is an observational finding and does not imply direct causality. Further studies are needed to examine these mechanisms in detail."