Consumer genetics and addiction susceptibility testing—just what the consumer ordered

Abstract

Mathews et al.'s paper argues that access to direct-to-consumer (DTC) genetic testing for addiction liability should be considered in light of the oversight, policies and practices of genetic tests offered in the course of health care. Here we seek to highlight the problems of restricting discussions of DTC genetic testing for addiction liability to the so-called ‘medical model’. The perceived benefits and harms of DTC genetic testing are measured according to their ability to ‘prevent addictive behaviour or reduce the harms of drug use’ 1. A consideration of recent empirical literature reveals that interest in DTC genetic testing for common diseases is not purely health- or welfare-related. This is especially true in the case of ‘personal genomics’ (PG). Studies of consumer uptake have found a multiplicity of motivations including curiosity, fascination or recreation 2-4. Tellingly, Neumann et al.'s recent survey of Americans suggested a ‘desire [to access] information for its own sake’, in the absence of direct treatment consequences 5. A test's predictive power or ability to generate clinically actionable information is not the sole measurement of its utility. Crucially, Mathews et al. assume one of the dominant justifications for increased regulatory oversight. That is, the risk that the healthy consumer will suffer unnecessary anxiety at learning a genetic propensity to an addiction-related dependency, for which no effective preventative strategies exist 1. This presumption is challenged by a growing body of empirical evidence. For example, the only large-scale study of the impact of testing on ‘real’ consumers found a marginal impact of the tests on anxiety symptoms 6. Similarly, a systematic review of all available empirical literature found ‘no evidence that communicating DNA-based risk information has any unintended detrimental effects on motivation or mood’ 7. There are, of course, limitations to the application of these studies to the context of addiction liability. There is already uncertainty as to whether the findings extend to the general population. This is particularly pertinent where demographic disparities may present between the average PG consumer (female, Caucasian and well educated, see for example 8), and the average addiction liability sufferer. Importantly, where there is the possibility that consumers could harmlessly enjoy learning addiction liability information, it arguably becomes a consumer good for which different ethical principles of access apply; for example, the principle of caveat emptor, or ‘let the buyer beware’ 9. However, is this necessarily problematic? As one commentator astutely put it: ‘The harsh truth [is] that, as it turns out, most genetic risk information just is not that predictive’ 10, and a genomic revolution is not around the corner, either. This reality also challenges the claim made by Mathews et al. about the relationship between genetics and privacy, and the potential for genetic discrimination. The authors are right to argue that the privacy protections offered by PG companies are vague, unsupervised and far from ideal. This is problematic, given the lack of consistent protections governing third-party access to both personal and genetic data. However, as Caulfield pointed out recently, ‘[t]he fact that most genetic risk information is not tremendously predictive… [is] at a minimum, [justification] for being cautious about any exceptionalist approach to the regulation of genetics’ 11. It overlooks a more pressing ethical and legal concern in this context; that is, the novel jurisdictional challenge presented to the protection of personal and genetic data. For example, what protections are afforded the customer who registers for a genetic test from a Californian company in England, uploads their basic personal information online while on a business trip to New York, and then downloads their genetic data when it becomes available while on holiday in Ireland? We have illustrated some of the problems of restricting discussion of DTC genetic testing for addiction liability to the medical model. That said, Mathews et al. mention other ethical concerns which are ripe for policy response, such as the unequivocal benefits of presenting the consumer with the option of genetic counselling 12, the impact of testing on an already overstretched health-care system and the need to ensure truth in advertising. We would also conclude with the caution that these discussions are purely speculative. Empirical and qualitative research is needed into the uptake, interests and long-term impact of DTC genetic testing for addiction liability, both among consumers who receive the results as part of a general testing service and those who seek DTC testing following a diagnosis of an addiction-related dependency. None.