The impact of treatment of depression on quality of life, disability and relapse in patients with Parkinson's disease.

Parkinson's disease (PD) is a common neurodegenerative disease affecting up to one million individuals in the United States. Depression is found in 40 to 50% of these patients and is associated with a variety of poor outcomes for both patients and their families. Despite this, there are few evidence-based data to guide clinical care. This was an NIH-funded, randomized, controlled trial of paroxetine, nortriptyline, and placebo. It included an 8 week acute phase and a 16 week blind extension phase. This report details the impact of depression treatment on quality of life (QoL) and disability in the acute and extension phase of this study. Secondary outcomes included relapse, tolerability, safety, and the impact of depression treatment on PD physical functioning. Patients who had improvement in depression, compared with those who did not, had significant gains in measures of QoL and disability (PDQ-8, P = 0.0001; SF-36, P = 0.0001) at 8 weeks and maintained their gains in the extension phase. Patients who were on active drug were significantly less likely to relapse in the extension phase than those on placebo (P = 0.041). Though relatively modest in size, this trial provides the first controlled data on the impact of treatment of depression on QoL and disability in PD. It suggests that successfully treating depression in PD leads to important, sustained improvements in these outcomes and that patients who improve on antidepressants are less likely to relapse than are patients who initially improve on placebo.