Translational research generally refers to the application of knowledge generated by advances in basic sciences research translated into new approaches for diagnosis, prevention, and treatment of disease. This direction is called bench-to-bedside. Psychiatry has similarly emphasized the basic sciences as the starting point of translational research. This article introduces the term translational epidemiology for psychiatry research as a bidirectional concept in which the knowledge generated from the bedside or the population can also be translated to the benches of laboratory science. Epidemiologic studies are primarily observational but can generate representative samples, novel designs, and hypotheses that can be translated into more tractable experimental approaches in the clinical and basic sciences. This bedside-to-bench concept has not been explicated in psychiatry, although there are an increasing number of examples in the research literature. This article describes selected epidemiologic designs, providing examples and opportunities for translational research from community surveys and prospective, birth cohort, and family-based designs. Rapid developments in informatics, emphases on large sample collection for genetic and biomarker studies, and interest in personalized medicine—which requires information on relative and absolute risk factors—make this topic timely. The approach described has implications for providing fresh metaphors to communicate complex issues in interdisciplinary collaborations and for training in epidemiology and other sciences in psychiatry.
Translational research generally refers to the application of knowledge generated by advances in basic sciences research translated into new approaches for prevention, diagnosis, and treatment of disease, followed by the introduction of innovations into clinical practice and health policy. This direction is called bench-to-bedside. Translational research has received increasing priority in recent years, by means of the National Institutes of Health's Road Map Plan, newly launched scientific journals (eg, http:// www.sciencetranslationalmedicine.org), new career programs, and the Clinical and Translational Science Award program. This emphasis is not just within the United States: the British Medical Research Council in 2007 established new translational medicine centers, one of which is devoted to translational epidemiology, and translational research has served as a centerpiece of the European Commission health budget.
Psychiatry has similarly emphasized the basic sciences as the starting point of translational research. Wang et al, in an explicit application of translation research to psychiatry, applied the Institute of Medicine's recommendations for translational research to schizophrenia and other psychotic disorders. They describe the application of 2 translational blocks. The first block, called T1, translates discoveries from the basic sciences into new diagnostic and preventive interventions, including early identification of high-risk individuals and new methods for testing interventions. In the second block, called T2, resulting clinical developments are received in clinical practice in comparative effectiveness studies, bridging the gap between diagnosis and actual treatment, providing health education, and changing prescribing practices. Within this bench-to-bedside framework, Wang et al argue, clinical epidemiology has played an important role in the design of clinical trials, prevention, health education, and service delivery.
The purpose of this article is to expand the term translational epidemiology into psychiatric research as a bidirectional concept in which the bedside, ie, the population, can also be translated into the benches of laboratory science. This approach uses epidemiologic designs and findings to facilitate or to partner with basic science research. We will apply this concept of translational epidemiology to psychiatry and demonstrate that the representative samples, novel designs, and hypotheses offered by epidemiology can be translated into more tractable experimental approaches in the clinical and basic sciences. Because the validity, interpretation, and generalizability of findings vary by design, we provide a brief overview of core epidemiologic designs and provide illustrations of translational applications with each design. The discussion of design is not intended as a substitute for an exhaustive review of epidemiologic design, for which we direct the reader to one of many excellent textbooks. We also do not intend to appropriate bedside-to-bench as a novel direction. There are a number of classic examples in medicine, such as the epidemiologic observation of the relationship between smoking and lung cancer, which led to animal studies demonstrating the carcinogenic effect of nicotine and other cigarette toxins.
This approach does not contradict the literature on bench-to-bedside translation; rather, it is complementary and iterative. The use of epidemiology in bedside-to-bench translational research in psychiatry has not been fully explicated, even though a number of studies appearing in the psychiatric literature have indirectly used epidemiologic designs. It is useful to make this idea explicit because epidemiology can provide hypotheses, designs, and samples for basic research, and the failure to avail oneself of these resources can lead to lost opportunities. Furthermore, different epidemiologic designs answer different questions, and inappropriate designs or inferences, particularly generalization of findings across designs, can confound results
