Fig. 1From: Treatment patterns and sequences of pharmacotherapy for patients diagnosed with depression in the United States: 2014 through 2019Study design illustration for drug eras, switching and combination therapy classification. a Drug eras are illustrated assuming a 30-day supply for each medication fill and allowing for a 30-day gap between the end of supply and the next fill. The drug era ends if another fill is not received within this gap. b If drug eras of two classes overlap at least 30 days (Drug Class B and Drug Class C) then it is classified as combination therapy, otherwise it is a switch between two classes (Drug Class A to Drug Class B)Back to article page