In the past decade, we have become increasingly aware of strong associations between overweight/obesity and symptoms of attention-deficit/hyperactivity disorder (ADHD) in children, adolescents, and adults. This review addresses the prevalence of the comorbidity and discusses some of the mechanisms that could account for their relationship. It is suggested that the inattentive and impulsive behaviors that characterize ADHD could contribute to overeating in our current food environment, with its emphasis on fast food consumption and its many food temptations. It is also proposed-based on the compelling evidence that foods high in fat, sugar, and salt are as addictive as some drugs of abuse-that excessive food consumption could be a form of self-medication. This view conforms with the well-established evidence that drug use and abuse are substantially higher among those with ADHD than among the general population.