 knowledge and support that individual families need in implementing these diets.
What Are the Directions for Research?
The Panel identified a number of critical gaps in knowledge which affect interpretation of the results of dietary intervention in the management of the hyperactivity syndrome. These deficiencies include nonuniform diagnostic standards and inadequate information regarding the natural history of this syndrome, lack of availability of optimal measurement instruments (behavioral, cognitive, and other), and other significant limitations in the research study designs employed to date. In addition, the full potential of animal and in vitro studies for generating relevant biologic information has not been realized. Therefore, further research in each of these areas is needed to be able to conduct meaningful investigations of the potential benefits of dietary management of hyperactivity.
The following directions for further research are recommended:
- Epidemiologic studies --Including: the development of standardized working diagnostic criteria (essential for all research in this disorder), and possible neurophysiologic, biochemical, or other diagnostic "markers." Studies of the etiology and risk factors for the condition and delineation of its natural history are needed. Such studies should address possible genetic, developmental, and environmental factors which could both be causal and also serve as predictors of prognosis and should better define those afflicted children who may be likely to respond to a given therapy. Several of these goals require longitudinal prospective studies. For this purpose, it is recommended that existing defined populations and data sources be identified and employed whenever possible.
- Psychosocial/behavioral --The development and utilization of standardized instruments for the assessment of cognitive, attentional, and behavioral changes in patients receiving different modalities of therapy is essential. This may involve the adaptation of existing instruments or the development of new ones for these purposes. Investigations of family dynamics are essential for understanding the impact of both the disorder and the different modalities of therapy.
- Diet --Further dietary research is needed with improved study design, including particular attention to certain features such as adequate sample size, explicit criteria for selection of subjects, ensuring and monitoring compliance, precise definition of the diet or dietary agent being tested, and consideration of synergistic effects of simultaneous exposure to additional dietary and/or other agents. Randomized, double-blind trials with checks on the adequacy of the blinding and repetitive evaluations are needed. Moreover, studies are also needed of the possible adverse effects of dietary intervention, on both the patient and the family, and of both a biologic and a psychosocial nature. These types of studies are essential for risk-benefit assessments that should also be carried out for other nondietary options of therapy.
- Animal studies --These studies offer an obvious opportunity for obtaining relevant biologic information. However, such studies should be conducted with particular attention to dosages of specific test substances, standardization of rigorously defined synthetic diets, routes of administration, and genetic factors. These studies should provide important information regarding the absorption, distribution, metabolism, and mechanism of action of the agents being tested and may be particularly relevant for human populations if appropriate behavioral endpoints in the animal model can be developed.
Consensus Development Panel
Floyd W. Denny, M.D.
Professor of Pediatrics
University of North Carolina School of Medicine
Chapel Hill, North Carolina
Leon Gordis, M.D., Dr.P.H.
Professor and Chairman
Department of Epidemiology
Johns Hopkins University School of Hygiene and Public Health
Morris Green, M.D.
Perry W. Lesh Professor and Chairman
Department of Pediatrics
Indiana University School of Medicine
Samuel W. Greenhouse, Ph.D.
