Prevention of Intellectual and Developmental Disabilities

The first plenary session of 132nd Annual Meeting of the American Association on Intellectual and Developmental Disabilities (AAIDD) reflected its support for basic and applied research to prevent or minimize the effects of conditions causing developmental disabilities, with Dr. Alan Guttmacher (2008), currently the acting director of the National Human Genome Research Institute, discussing the realized and potential benefits of genomics research on health and quality of life. This presentation dealt with an incredibly complex topic with clarity and sensitivity, and it was carefully neutral in tone and content with respect to intellectual and developmental disabilities. Nevertheless, a major implication regarding disabilities in general and developmental disabilities more specifically was quite clear. Current research in genomics, as well as in many other areas, is intended to improve understanding of the fundamental causes of disability to reduce risk, thereby lowering incidence of impairments and minimizing their severity. Should these goals be realized, the proportion of the population with disability would decrease, perhaps dramatically, and in some distant future significant impairments might even be eliminated altogether. As unachievable as that ultimate goal might appear to be, an assumption supporting many of the programs and much of the research agenda in the field of developmental disabilities is that we, as a society and as individuals, would be better off if physical, mental, and cognitive impairments ceased to exist. Yet, prevention encompasses many things and can be viewed from many perspectives, some of which have continued to challenge the universality of this assumption. There is a need for serious and open discussion of the many aspects of prevention within our field (and the disabilities field more generally) that entails explicit consideration of risks and benefits of specific programs and approaches to implementation. Although important distinctions can and should be made among primary prevention (avoiding the occurrence of a causal condition), secondary prevention (avoiding or minimizing the consequences of a causal condition after it occurs), and tertiary prevention (minimizing or improving outcomes after the consequences of a causal condition are evident), this dialogue needs to begin with consideration of the overarching goal of lowering the incidence and prevalence of impairments and reducing disability. In many respects, prevention was embraced long ago as a valued societal benefit, and this has had significant impacts in the case of intellectual and developmental disabilities. Certainly, the history of prevention in our own field has included some policies and actions that had devastating consequences for people with intellectual and developmental disabilities, and careful and constant vigilance will always be required to ensure that the rights, privileges, and dignity of every individual are respected and preserved. Nevertheless, many other aspects of the past continue to be broadly viewed as enormously beneficial, and several examples seem particularly illustrative. Until the late 19th century, congenital hypothyroidism (cretinism) caused many individuals in western Europe to have intellectual disability. For some alpine regions, it was so common an occurrence that local physicians thought it unremarkable (Merke, 1984). We now know that this condition is caused by dietary iodine deficiency, and this discovery, along with the availability of iodized salt, has virtually eliminated it as a public health concern in industrialized countries. (Nevertheless, congenital hypothyroidism remains one of the most common preventable causes of intellectual impairment in many underdeveloped regions of the world; Jain, Agarwal, Deorari, & Paul, 2008.) Prior to the 1950s, babies born with phenylketonuria (PKU), a relatively rare genetic disorder, were unimpaired at birth but invariably developed severe intellectual disabilities. This was caused by their inability to metabolize phenylalanine, a INTELLECTUAL AND DEVELOPMENTAL DISABILITIES VOLUME 47, NUMBER 4: 320–322 | AUGUST 2009