Differences in CSF concentrations of thyrotropin-releasing hormone in depressed patients and normal subjects: negative findings

Since there have been reports of elevated CSF concentrations of thyrotropin-releasing hormone (TRH) in depression, the authors compared the TRH levels of 17 depressed patients and 19 normal subjects. All subjects underwent lumbar punctures after fasting overnight, and CSF concentrations of TRH were determined by radioimmunoassay. CSF concentrations of norepinephrine and monoamine metabolites were also measured. There was no significant difference between the two groups on any measure, and in the depressed patients there was no significant relation between CSF concentrations of TRH and thyrotropin-stimulating hormone responses to TRH infusion.