Treatment with COMT inhibitors was associated with relatively improved depression symptoms as the disease progressed (β=−0.37, 95%CI [−0.72, −0.01], p=0.041), but worse symptoms on average across all years of follow up (β=2.2, 95%CI[0.43, 4.1], p=0.015) (Supplemental Figure S1). Here, COMT is linked to depressive disorder.