Studies on the influence of biogenic amines and psychoactive drugs on the prognostic value of the TRH stimulation test in endogenous depression

(1) By means of the variations in the maximal thyroid-stimulating hormone (TSH) response to thyrotropin-releasing hormone (TRH) before and after treatment it was possible to predict early relapse in all of 14 patients, and a recovery continuing more than 6 months in five of seven patients with endogenous depression. (2) The prognostic value was not affected by small doses of phenothiazines and benzodiazepines. (3) Short-term administration of chlorpromazine resulted in a small, but significant ( p < 0.05) increase in the maximal TSH response to TRH. (4) Short-term administration of imipramine and diazepam did not affect the TSH response, neither did manipulation of adrenergic α- and β-receptors nor administration of l-5-OH-tryptophan.