ULTRASENSITIVE ASSAY FOR MEASURING THE INTACT (1-39) ACTH MOLECULE - AN ASSET IN DEPRESSION RESEARCH

This study investigates the utility for depression research of an assa y for intact (1-39) adrenocorticotropic hormone (ACTH) versus that of a previously employed(i.e., 1-17, 1-24 sequences) ACTH assay. ACTH pla sma levels were measured using two different ACTH assays (labeled as i ntact versus nonintact) in 10 minor and 27 major depressed subjects un dergoing the combined dexamethasone suppression (DST) and corticotropi n-releasing hormone (CRH) test. Intact - but not nonintact - ACTH valu es were significantly correlated with the severity of illness. Major d epressed subjects exhibited significantly higher post-DST+CRH intact A CTH values than minor depressives, whereas nonintact ACTH values were not significantly different between these groups. Post-DST+CRH intact ACTH values were significantly more closely related to post-DST+CRH co rtisol than nonintact ACTH values. It is concluded that the assay of t he intact ACTH molecule is an asset in depression research and should replace the previous less specific and sensitive ACTH assays.