A functional-dimensional approach to depression: serotonin deficiency as a target syndrome in a comparison of 5-hydroxytryptophan and fluvoxamine.

H.M. van Praag has been suggesting a reappraisal of syndromes in psychiatry for over 20 years. He has tried to define syndromes originating from the same biochemical disorder. He has denoted this concept as 'functional psychopathology'. As an example of such a functional syndrome, he has cited the serotonin-shortage syndrome which unifies various psychiatric symptoms under a new point of view. The treatment of the serotonin-shortage syndrome is best served by psychopharmaca which raise the metabolism of serotonin in the synaptic cleft, e.g. the selective serotonin re-uptake inhibitors. Borrowing F. Freyhan's concept of 'target symptoms', one can now speak of 'functional target syndromes', within the frame of functional psychopathology.