Elevated 3,4-dihydroxyphenylethyleneglycol (DHPG) excretion in dexamethasone resistant depressed patients.

Urinary and plasma DHPG and MHPG were estimated in patients with MADD and showing DST non-suppression as compared to those with normal suppression. Day and night 12h urine collections and morning plasma samples were analyzed by GC-MS for total MHPG and DHPG and free MHPG levels. Urinary DHPG excretion was significantly elevated in DST non-suppressors compared to suppressors, but no differences were found in urinary MHPG or plasma glycol levels. Elevated DHPG excretion in DST non-suppressors suggests that increased peripheral sympathetic NE activity occurs in association with dexamethasone resistance in MADD.