title: Letter: Tryptophan plus a pyrrolase inhibitor for depression?
mesh_terms: D000493:Allopurinol / Q000008:administration & dosage / Q000627:therapeutic use*; D001921:Brain / Q000378:metabolism; D003863:Depression / Q000188:drug therapy* / Q000378:metabolism; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D006801:Humans; D009536:Niacinamide / Q000008:administration & dosage / Q000627:therapeutic use; D013997:Time Factors; D014364:Tryptophan / Q000008:administration & dosage / Q000378:metabolism / Q000627:therapeutic use*
chemical_list: D009536:Niacinamide; D000493:Allopurinol; D014364:Tryptophan