Mood response to levodopa infusion in early Parkinson's disease.

Mood response to levodopa infusion was studied in 18 Parkinson's disease (PD) patients during the first year of levodopa therapy before and after 2-hour (1.0 mg/kg/h) levodopa infusions at baseline and 6- and 12-month follow-up. Mood elevation was greatest after a 2-day levodopa holiday at the 6- and 12-month assessments. Age, sex, duration and severity of PD, and ongoing oral levodopa dose did not correlate with mood response. Mood response in these patients differs from that seen in advanced patients, possibly because of sensitization to levodopa's mood effects.