Changes in urinary catecholamines and their metabolites in depressed patients treated with amitriptyline or imipramine

The effects of treatment with amitriptyline (AMI) or imipramine (IMI) on changes in catecholamines and their metabolites in urine were studied in 95 unipolar and bipolar depressed patients. For the entire group, not separated by drug, substantial reduction in concentrations of all metabolites, but not catecholamines, occurred. Although catecholamine and metabolite change was similar for most substances assayed, there were some specific drug and diagnostic group differences. Vanillylmandelic acid (VMA) reduction was limited to bipolar patients; metanephrine (M) reduction to unipolar patients. Greater M and 3-methoxy-4-hydroxyphenylglycol (MHPG) reduction were associated with response in unipolar, but not bipolar patients. In bipolar, but not unipolar patients, norepinephrine (NE) rose in responders in contrast to reductions among nonresponding bipolar patients. The results suggest that effectiveness of blockade of reuptake of norepinephrine may be relatively more important for recovery in bipolar than in unipolar patients. Study of a battery of amine substances may contribute more information to our understanding of antidepressant drug effects on aminergic systems than analyses of MHPG alone.