CA research in depressions is reviewed. The present situation can be outlined as follows.

• Vital depressive patients can show central CA disorders which point in the direction of CA deficiency. In principle, this deficiency can be a primary phenomenon or a secondary development: the result of hypersensitivity of postsynaptic CA receptors. The former possibility is considered more plausible than the Jatter.
• The DA disorder seems to be related to motor retardation and loss of initiative, and probably plays a role in their pathogenesis. There is no reason to assume that this disorder is a predisposing factor.
• The NA disorder is not related to motor symptoms. Its causative significance is still uncertain.
• An important 'by-product' of CA research in depressions is the momentum it gives to attempts to 'translate' behaviour disorders in terms of disturbed psychological functions. Such a functional psychopathology could be an important supplement to the traditional, more syndromal and nosological classification of psychiatrie conditions.