Serotonin Metabolism in Depression: Clinical Application of the Probenecid Test1

The MA hypotheses presume a relationship between disturbances in the central MA metabolism and the occurrence of depressive symptoms. One part of the MA hypotheses is the serotonin hypothesis, in which a relation is presumed between central serotonin deficiency and depression. The arguments in favour of this hypothesis are discussed, and particular attention is paid to data collected with the probenecid technique. The conclusion is, that there are depressions with and without serotonin deficiency and that their differentiation is of importance for proper treatment.