Since 1997 the US National Institute on Drug Abuse has advocated a brain disease model of addiction (BDMA). We assess the strength of evidence for the BDMA in animals, neuroimaging studies of people with addiction, and current research on the role of genetics in addiction. We critically assess claims about the medical and social benefits of use of the BDMA because the social implications are often implied as a reason to accept this model. Furthermore, we argue that the BDMA is not supported by animal and neuroimaging evidence to the extent its advocates suggest; it has not helped to deliver more effective treatments for addiction; and its effect on public policies toward drugs and people with addiction has been modest. The focus of the BDMA is on disordered neurobiology in a minority of severely addicted individuals, which undermines the implementation of effective and cost-effective policies at the population level to discourage people from smoking tobacco and drinking heavily. The pursuit of high technology direct brain interventions to cure addiction when most individuals with addiction do not have access to effective psychosocial and drug treatments is questionable.

There is mounting evidence that methylphenidate (MPH; Ritalin) is being used by healthy college students to improve concentration, alertness, and academic performance. One of the key concerns associated with such use of pharmaceuticals is the degree of freedom individuals have to engage in or abstain from cognitive enhancement (CE). From a pragmatic perspective, careful examination of the ethics of acts and contexts in which they arise includes considering coercion and social pressures to enhance cognition. We were interested in understanding how university students, parents of university students, and healthcare providers viewed autonomy and coercion in CE using MPH. We found that perspectives converged on the belief that CE is a matter of personal and individual choice. Perspectives also converged on the existence of tremendous social pressures to perform and succeed. Parents emphasized personal responsibility and accountability for CE choices, and expressed feelings of worry, sadness and fear about CE. Students emphasized the importance of personal integrity in CE, expressed tolerance for personal choices of others, and highlighted the challenge that CE poses to maintaining one's personal integrity. Healthcare providers emphasized the health consequences of CE. These results illustrate: (1) the importance of understanding how context is viewed in relation to perspectives on autonomous choice; (2) the limitations of individualistic libertarian approaches that do not consider social context; and (3) the ethical implications of public health interventions in a valueladen debate where perspectives diverge.

The prospects of enhancing cognitive or motor functions using neuroscience in otherwise healthy individuals has attracted considerable attention and interest in neuroethics (Farah et al., Nature Reviews Neuroscience 5:421-425, 2004; Glannon Journal of Medical Ethics 32:74-78, 2006). The use of stimulants is one of the areas which has propelled the discussion on the potential for neuroscience to yield cognition-enhancing products. However, we have found in our review of the literature that the paradigms used to discuss the non-medical use of stimulant drugs prescribed for attention deficit/hyperactivity disorder (ADHD) vary considerably. In this brief communication, we identify three common paradigms-prescription drug abuse, cognitive enhancement, and lifestyle use of pharmaceuticals-and briefly highlight how divergences between paradigms create important "ethics blind spots".