Effects of methylphenidate and MDMA on appraisal of erotic stimuli and intimate relationships

In a double-blind, placebo-controlled crossover study with 30 healthy adults, a single 40 mg dose of methylphenidate increased subjective ratings of sexual arousal when viewing explicit erotic pictures and led participants to press a button to prolong viewing of implicit sexual stimuli, whereas a 75 mg dose of MDMA did not alter sexual arousal. Neither drug changed how participants appraised the romantic relationships of unknown couples. Blood levels of testosterone, estrogen, and progesterone were unrelated to arousal ratings. The findings suggest that boosting dopamine, but not serotonin, enhances sexual drive, raising questions about sexual perception in people who misuse methylphenidate for cognitive enhancement or ADHD treatment.

Study at a glance

Abstract

Methylphenidate mainly enhances dopamine neurotransmission whereas 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") mainly enhances serotonin neurotransmission. However, both drugs also induce a weaker increase of cerebral noradrenaline exerting sympathomimetic properties. Dopaminergic psychostimulants are reported to increase sexual drive, while serotonergic drugs typically impair sexual arousal and functions. Additionally, serotonin has also been shown to modulate cognitive perception of romantic relationships. Whether methylphenidate or MDMA alter sexual arousal or cognitive appraisal of intimate relationships is not known. Thus, we evaluated effects of methylphenidate (40 mg) and MDMA (75 mg) on subjective sexual arousal by viewing erotic pictures and on perception of romantic relationships of unknown couples in a double-blind, randomized, placebo-controlled, crossover study in 30 healthy adults. Methylphenidate, but not MDMA, increased ratings of sexual arousal for explicit sexual stimuli. The participants also sought to increase the presentation time of implicit sexual stimuli by button press after methylphenidate treatment compared with placebo. Plasma levels of testosterone, estrogen, and progesterone were not associated with sexual arousal ratings. Neither MDMA nor methylphenidate altered appraisal of romantic relationships of others. The findings indicate that pharmacological stimulation of dopaminergic but not of serotonergic neurotransmission enhances sexual drive. Whether sexual perception is altered in subjects misusing methylphenidate e.g., for cognitive enhancement or as treatment for attention deficit hyperactivity disorder is of high interest and warrants further investigation.