"Food allergy" as a cause of behavioral abnormalities has been advocated by many physicians but the scientific basis for this association is virtually unknown. The food-behavior association itself is considered highly suspect by many other many other workers. The aims of this proposal are 1) to develop a standardized, rigorous, statistically sound protocol for testing the presence or absence of food-related behavioral reactions and 2) to study reactions of elements of the immune system to food to determine which - if any - are associated with behavioral effects. Patient subjects - individuals with suspected food-induced behavioral reactions - and normal controls will receive standard preparations of food prepared and administered in a randomized, double-blind, placebocontrolled design. Changes in behavior will be self-rated and rated by blind observers. Videotaped segments will be rated by another set of blind observers. Standardized, validated rating scales of behavior will be used. Before and during these food challenges, immune measures including T and B-cell subpopulations, immune complexes, HLA-Ia populations, complement levels, and evidence for lymphocyte stimulation and blastogenesis will be studied. Suggestive evidence in the literature and from pilot studies indicates that one or more of these parameters may be associated with food-related alterations in behavior. These studies are the first in which an adequate series of patients and controls will be studied with careful attention to double-blind conditions. By establishing a scientific basis - if any - for food-induced behavioral reactions more rational treatment can be developed. If this study fails to demonstrate either a significant relationship between food and behavior or between food and immune changes, then this study would represent a strong case against allergy and immunology as a basis for treating behavioral conditions.