Citalopram Challenge Test - Serotonin Activity Marker and Potentional Depression Marker

Summary

The citalopram challenge test (CCT) is a new neuroendocrinological test which shows serotoner-gic activity via prolactin and cortisol plasma levels. Advantages of the CCT comparing to thefenfluramine challenge test are: parenteral i.v. - administration - high citalopram selectivity andsafety. The aim of the study was to elaborate the methodology of CCT, to gather groups of 1)depressive patients, 2) anxious patients and 3) healthy volunteers; and to check the hypothesisabout flattening of the hormonal peak in the group of depressive patients and excessive hormonalpeak in the group of anxious patients, and the hypothesis about the normalization of such modifi-ed responses after antidepressant treatment. The methodology of CCT, observed parameters,obtained data and results are presented: final statistical processing of 3 groups (n = 3x10) showsa constant serotonin response 30-40 minutes after rapid citalopram infusion. PRL response wassignificantly flattened in the group of depressive patients (p < 0.05). There was no significantfinding of excessive response in the group of anxiety disorders. Basal plasma levels of PRL ofanxious patients were higher than the levels of the control group (p < 0.05). Criteria of positivityof CCT for depression are suggested: prolactin level after citalopram infusion not higher than125% of the basal level. Other statistical issues are analyzed. The CCT could be a marker ofdepressive disorders after a more extensive validization.

Key words:
citalopram, challenge test, depression, anxiety disorder, prolactin, cortisol.