The NINDS NET-PD investigators are studying the effects of the drug pioglitazone taken once daily. In the study, 216 men and women with early Parkinson's disease will receive pioglitazone or a matching placebo (an inactive substance). Researchers will compare two doses of pioglitazone—15 and 45 milligrams, with a placebo to find out how it effects the progression of Parkinson's disease over 44 weeks.

Pioglitazone is currently approved by the FDA to treat type II diabetes. It may be useful in slowing the progression of Parkinson's disease.

This study will also explore the effect of pioglitazone on motor skills, cognitive function, mood, and biomarkers. Biomarkers are biological characteristics or features that can provide information on how the disease changes over time and may be useful in developing new treatments and improving clinical care in the future.