At this stage of our knowledge, it seems reasonable to assume that out-of-control sexual behavior results from a variety of etiological mechanisms associated with different behavioral patterns that share Goodman's two key features of addictive behavior: (1) a recurrent failure to control the sexual behavior; and (2) continuation of the behavior despite harmful consequences. Any overriding definition relevant to clinical management seems premature until we better understand the various patterns and their likely determinants. The concepts of "compulsivity" and "addiction" may have explanatory value in some cases, but are not helpful when used as general terms for this class of behavior problem. Stein and colleagues suggested that, in these circumstances, we use the term "hypersexuality." In my opinion, out-of-control sexual behavior or "impulse control disorders" as proposed by Barth and Kinder are more appropriate nonspecific terms because they focus on the issue of control rather than on high levels of sexuality. A number of clinically relevant and researchable hypotheses need to be addressed in further research, which hopefully will lead to more etiologically or therapeutically relevant subcategories of out-of-control sexual behavior.