Clinical correlates of the TRH infusion test in primary depression.

Relationships between clinical measures, diagnosis and neuroendocrine findings were examined in a group of 25 primary depressives maintained drug free on a Neuropsychiatric Evaluation Unit. The TSH response to TRH infusion curves for unipolar and bipolar depressives were significantly different. Agitated patients but not psychomotor retarded patients demonstrated a blunted TSH response curve. No relationships were noted for cortisol hypersecretion and/or loss of diurnality and either diagnosis or psychomotor activity levels in depression. Biochemical and diagnostic implications of these findings are discussed.