Mood changes associated with "end-of-dose deterioration" in Parkinson's disease: a controlled study.

Fluctuations of mood and psychic activation were assessed in relation to "mobile" and "immobile" periods in 18 patients with Parkinson's disease presenting typical "end-of-dose deterioration". Twelve subjects with chronic but active rheumatoid arthritis presenting increased physical disability due to severe morning joint stiffness with a repetitive pattern of mobile and immobile periods acted as controls. The overall degree of disability and its fluctuations were close enough in the two groups for fair comparison of changes in affective behaviour. Temporary immobility was accompanied by adverse changes of mood and activation, which were significantly more marked in the Parkinson's disease group than in the controls, though to a lesser extent in those Parkinson's disease patients rated depressed even in their mobile periods. The possible correlation between mood changes and fluctuations of central dopaminergic function in the Parkinson's disease patients is discussed.