Pretreatment neurotransmitter metabolite levels and response to tricyclic antidepressant drugs.

Relationships between pretreatment neurotransmitter metabolite levels and response to imipramine and amitriptyline were studied in 104 depressed patients. Normal values for urinary norepinephrine and low values for urinary MHPG were associated with greater incidence of drug response in bipolar, but not unipolar, patients. For unipolar, but not bipolar, patients low CSF 5-HIAA and high urinary metanephrine values were associated with a greater incidence of drug response. These data indicate that the pretreatment functional state of catecholamine and serotonin systems is associated with type of response to drug treatment. The authors present hypotheses about the association of alterations in serotonin and norepinephrine systems and definable subtypes of depression.