PLASMA MHPG AND AMDP DEPRESSION RELATIONS, EVOLUTION AND DRUG EFFECT IN A FOLLOW-UP-STUDY OF DEPRESSED-PATIENTS

Plasma MHPG levels and AMDP rating score were measured in depressed patients before treatment, and a follow-up study was performed during the next 3 months of drug therapy to detect possible relationships between the parameters. Before treatment, MHPG levels were moderately lower in depressed than in age- and sex-matched normal subjects. Bipolar depressed patients presented the lowest values. In the three diagnostic groups (DSM-III), antidepressant treatment resulted in a significant decrease of mean levels in unipolar and dysthymic depressed, but not in bipolar depressed patients. When the type of antidepressant was considered, imipramine (IMI)- or desipramine (DMI)-treated patients, but not fluvoxamine (FLU)-treated, also decreased their mean values of MHPG, with minor difference between improved and non-improved patients. However, when patients were grouped according to their pattern groups (low (LL), high (HL), or normal (NL) baseline MHPG levels), interesting information emerged: improvement of clinical state of patient (i.e. 60 per cent of AMDP baseline reduction) resulted in 'normalization' of erratic values (HL and NL) whatever the treatment, while in non-improved patients such evolution was not observed. In the latter group, change in MHPG levels was only drug-related (decrease in IMI-DMI-treated and no change in FLU-treated values). Results suggest that mechanisms of buffering NA activity were lost in endogenous depression and restored in patients responding to treatment.