When baseline red blood cell catechol O-methyltransferase (COMT) was
measured in 15 unipolar depressive women, the authors found a linear
correlation between COMT and response to imipramine (best outcome occurring
at low COMT). The results of this study were not related to such variables
as intensity of depression, family history, or psychiatric history. The
authors suggest that this assay may be useful either as a predictor of
response to the drug or as a guide in choosing the optimum dose.