Dysphoria associated with methylphenidate infusion in borderline personality disorder.

Two patients with borderline personality disorder experienced dramatic dysphoric episodes after acute administration of intravenous methylphenidate in a double-blind manner. These dysphoric episodes were similar to those which occurred spontaneously under conditions of psychological stress. Case histories and the behavioral and cardiovascular effects of the infusions are described. The pharmacology of methylphenidate is discussed in order to elucidate possible mechanisms mediating the observed responses to this drug.