Enkephalins and the action of psychotropic drugs.

This paper reviews data concerning the possible role of opioid neuropeptides in the central action of psychotropic drugs. The results summarized provide an evidence that the long term interruption of the central dopaminergic mechanisms by administration of neuroleptics causes specific alterations in the content, release and biosynthesis of several opioid peptides. Moreover, the dynamic changes of the enkephalin level in brain structures after one year of fluphenazine administration were described. The acute and chronic treatment with benzodiazepines induced pronounced changes in brain enkephalin concentrations. The first evidences are provided that chronic antidepressant treatment changes the level of enkephalins in discrete brain areas.