title: Change in serum antidepressant level at a constant dose of medication.
mesh_terms: D003866:Depressive Disorder / Q000097:blood / Q000188:drug therapy* / Q000523:psychology; D004361:Drug Tolerance; D005260:Female; D006801:Humans; D008875:Middle Aged; D009661:Nortriptyline / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use; D012008:Recurrence
chemical_list: D009661:Nortriptyline