Impulsivity and compulsivity have been considered opposite poles of a continuous spectrum, but their relationship seems to be more complex. Disorders characterized by impulsivity often have features of compulsivity and vice-versa. Impulse-control disorders (ICDs) are characterized by repetitive behaviors and impaired inhibition of these behaviors, suggesting a similarity to the frequently excessive, unnecessary, and unwanted rituals of obsessive-compulsive disorder (OCD). There are, however, important differences be-tween ICDs and OCD. The construct of compulsivity as related to ICDs and OCD warrants additional investigation to identify the similarities and differences and to examine the implications for prevention and treatment strategies.