A 6-week multicenter, double-blind, controlled study comparing the therapeutic efficacy of two antidepressant drugs, trazodone and fluoxetine, was conducted. The hematocrit, hemoglobin, red blood cell count, serum cholesterol, serum calcium, and serum albumin levels were all significantly decreased after six weeks of trazodone treatment. Similar findings were not obvious for the fluoxetine treatment group. Trazodone caused the development of a pseudoanemia in 36% of the trazodone treatment patients compared with 20% of the fluoxetine treatment patients. The anemia was not regarded as clinically significant. Of the decreases in the patients' chemistries, only the decrease in cholesterol could not be reconciled.