• The value of neuroendocrine techniques for providing information regarding the pathophysiology of psychotic disorders is largely dependent on clarification of the relationships among psychologic state, neural activity, and neuroendocrine regulation. This study presents a strategy for examining the interface between neurochemical activity, psychologic state, and neuroendocrine regulation. Psychologic state and serum growth hormone (GH) and cortisol were monitored following administration of methylphenidate hydrochloride, a drug that appears to preferentially affect central dopamine regulation. While individuals varied in both their endocrine and psychologic responses to methylphenidate, the general effects were GH elevation, euphoria, and activation with elation, the most pronounced psychologic effect. Subjects who showed GH elevation became elated while those who did not show a GH response did not become elated. Elation and GH release following administration of methylphenidate may be mediated by the same neurochemical events.