New evidence of serotonin-deficient depressions

In 30 patients suffering from vital depression (the syndrome of endogenous depression) a negative correlation was found between the pre-therapeutic post-probenecid CSF 5-HIAA response and the therapeutic response to clomipramine (Anafranil). Clomipramine is a tricyclic antidepressant with a strong potentiating effect on central 5-HT. The following conclusion was drawn: if the cenral 5-HT turnover is diminished in depressions, then correction of this biochemical disturbance leads to alleviation of depressive symptoms. This finding is considered to support the concept of '5-HT-deficient depression'. Five of the 8 clomipramine-resistant patients showed a favourable response to nortriptyline, a NA-potentiating anti-depressant. The pre-therapeutic CSF MHPG concentration in these patients was not related to the therapeutic efficacy of nortriptyline. So, the assumption that these patients have been NA-deficient was not confirmed. However, renal MHPG excretion was not measured and possibly this variable correlates better with cerebral NA metabilism than MHPG in lumbar CSF which is of mainly spinal origin.