Levodopa treatment of presenile dementia.

In Parkinson's disease as well as presenile dementia there is a dopamine deficit in the basal ganglia. Extrapyramidal symptoms are common in presenile dementia, and dementia is a common trait in Parkinsonism. It is reasonable to suggest a partial common etiology and pathophysiology, and the logical consequence is an investigation of levodopa substitution is presenile dementia. Until now very few reports of such studies have been published. The investigations have been uncontrolled or carried out on small or inhomogeneous materials. This investigation is triple-blind, clinically controlled, and the material is very homogenous. After 6 months' levodopa treatment no significant effect is shown either on a broad spectrum of psychiatric items or in cognitive functioning. This negative result is discussed. The probability of a specific Parkinson dementia is mentioned and the significance of the modifying effect of an imbalance in other transmitter systems is emphasized.