The thyrotropin-releasing hormone (TRH) test was performed in 100 depressed patients, including 73 patients with a major depressive episode (MDE) according to DSM-III. Thirty-one patients subsequently received an antidepressant with a predominant serotoninergic action (indalpine or citalopram), and 27 patients received a noradrenergic antidepressant (maprotiline). The diagnostic value of the TRH test was not conclusive for any of the subgroups of depressed patients: MDE, MDE with melancholia or MDE in bipolar patients. Similarly, the value of the TRH test in the choice of antidepressant treatment according to the monoaminergic action was not convincing. These results are discussed in the light of the data of the international literature.