Measured were the effects of a diet climinating natural salicylates, preservatives, artificial coloring and artificial flavoring on the hyperactive behavior of a 4-year-old boy. Two of four behavioral measures showed a statistically significant reduction in hyperactivity when the diet was introduced. However, when the diet was terminated, the S continued to exhibit a reduction in hyperactivity in all four behavioral measures. In addition, the reduction in hyperactivity was not clinically noticeable in other aspects of the S's daily routine. It was concluded that the additive-free diet was not instrumental in reducing the S's hyperactive behavior. (Author/CL)