The use and abuse of clonidine as a psychopharmacological tool

Because early reports on the mechanisms of action of clonidine emphasized its "pure" postsynaptic alpha-norepinephrine stimulatory properties. clonidine has enjoyed an ever-growing popularity in psychoneuroendocrinology research as a central NE agonist. Clonidine appears to have some psychotropic activity. However, its biphasic and sometimes unpredictable effects (such as the ones we obtained in our laboratory) and the evidence of activity at presynaptic receptors which interfers with the NE feedback loop and turnover indicates that the rational for its use in research is in need of complete reevaluation and may be even opposite to the one heretofore utilized.