Parkinson's disease (PD), while defined by its motor abnormalities and associated dopaminergic loss, is invariably accompanied by cognitive impairment. Early in the disease course, the deficits are characterized by executive dysfunction with difficulties on tasks that involve information processing, attention, sorting, planning, set-shifting, and working memory and are subserved by neural connections with prefrontal brain regions. There has been little effort to identify treatments for these PD-related cognitive impairments, despite their disabling and distressing effects. Accordingly, the goal of this proposal is to conduct a small pilot study to determine the effectiveness and tolerability of atomoxetine, a selective norepinephrine reuptake inhibitor, for the treatment of executive dysfunction in patients with PD.