The suppression of appetite and food consumption by methylphenidate: the moderating effects of gender and weight status in healthy adults.

Females typically show greater behavioural responses to stimulant drugs than males, including loss of appetite; as seen, for example, in those who use methylphenidate (MP) therapeutically for treatment of attention deficit hyperactivity disorder (ADHD). This is a relevant issue because of the strong link between ADHD and obesity. In a sample (n=132) of normal-weight (BMI <25) and obese (BMI >30) men and women we assessed appetite, cravings, and snack-food intake in response to MP (0.5 mg/kg) and placebo. Results indicated a significant three-way interaction for the three dependent variables--food-related responding diminishing in all groups from placebo to MP, except in obese males who showed no decreases to the MP challenge. These data show for the first time the existence of gender differences in the appetite response to MP, and are relevant for finding a dopamine pathway to new weight-loss medications, which would be utilized differently in males than in females.