Methylphenidate and serum prolactin in man.

Methylphenidate induces psychostimulation and increases cardiovascular parameters, and its psychostimulant effects have been proposed to occur via a dopaminergic mechanism. The effect of methylphenidate on serum prolactin was utilized as a method of evaluating methylphenidate's central dopamimergic effects. Methylphenidate was not found to exhibit a consistent effect on serum prolactin. Thus, its effect on serum prolactin does not parallel its behavioral activating properties, suggesting that such activation may not involve dopamine. Possibly, norepinephrine or other noncatecholaminergic neurotransmitters are involved in methylphenidate-induced behavioral activation.