Plasma nortriptyline and clinical response--a study using changing plasma levels.

In a 5-week study of 22 depressed patients treated with nortriptyline, significant changes in plasma levels, both elevated and reduced, were deliberately produced in the third and fourth weeks of each patient's treatment. Correlation of plasma nortriptyline levels and changes in the severity of depression, as measured by the Hamilton Depression Scale, showed no significant relationships. The implications of the study are discussed.