The use of neuropeptide challenge tests as diagnostic adjuncts in psychiatry

In recent years, several neuropeptides were tested in psychiatric populations, particularly depression, as to their possible use as diagnostic tools. To date, results of most of these "tests" are equivocal and preliminary in nature. The measurement of serum TSH after administration of TRH, however, has revealed that approximately 25% of depressed patients show a blunted TSH response after TRH. TSH blunting, although not being specific for depression, may aid in assessing the response to antidepressant treatment, predicting outcome to such treatment, and assessing the risk of violent suicide attempts.