Grant: Operating Grant

Parkinson's disease (PD) is a progressive brain disease that causes severe motor disability. Recent studies have discovered that persons who did not drink coffee are at a higher risk of PD. This finding is robust, repeatable and has been confirmed in prospective studies in which exposure was measured decades before disease onset. Ar present, the reason for this finding is unclear - residual confounding, neuroprotection, or symptomatic motor benefit from caffeine are all plausible explanations. The most important piece of missing information is what effect caffeine has in persons affected with PD. PD patients with excessive sleepiness will be randomized to caffeine therapy or placebo (a pill with no caffeine in it) for six weeks. During this time, we will look at the effects of caffeine on excessive sleepiness and fatigue, whether it is well tolerated, and if it has effects on motor symptoms and quality of life. If caffeine does not help sleepiness or motor manifestations of PD, this could indicate that the apparent 'protective' effect of caffeine seen in population studies is, in fact, due to loss of benefit during a preclinical stage of disease (i.e. reverse causality). If caffeine can be shown to help sleepiness in PD, it will probably become the treatment of choice, providing a new treatment for one of the most disabling psychosocial symptoms of PD. If caffeine is shown to help motor symptoms, this will have obvious benefit for persons with PD. Therefore, despite its relatively small size and low cost, this trial will address numerous issues that may directly benefit patients with Parkinson's disease.