This article resumes the psychobiologic mechanisms involved in risk-seeking behaviour. The question is discussed whether some forms of high risk sports meet the diagnostic criteria of dependency. The intensive activation of the adrenocorticotropic pathway may yield to addiction: according to the model of emotion-focussed coping of stress, unpleasant emotion is "overwritten" by intense stress and hence better tolerated emotionally, leading to an addictive repetition of risk-seeking behaviour. In addition, pharmacologic mimicry seems possible as the perception of effects of catecholamines may imitate some of the effects of stimulating drugs. Finally, the current concept of risk and harm reduction is transferred to sports. This would mean to apply appropriate preventive interventions for a large variety of possibly dangerous activities.