Monoamine metabolism in senile dementia of Alzheimer type.

Monoamine metabolism in senile dementia of the Alzheimer-type (SDAT) was assessed by measuring the concentrations of the dopamine metabolite HVA, the noradrenaline metabolite MHPG and serotonin metabolite 5-hydroxy-3-indoleacetic acid (5-HIAA) in post-mortem brains of SDAT patients, a group of control subjects and a group of chronically depressed patients. Concentrations of MHPG and 5-HIAA were significantly reduced in hippocampus and cortical regions of the SDAT group. These changes did not correlate with clinical assessments of the degree of dementia or neuropathological assessment of the degree of Alzheimer-type changes in the SDAT group. It is suggested that changes in monoamine metabolite concentrations are not primarily involved in the pathogenesis of SDAT, and may be secondary to the well established cholinergic deficits.