The effects of essential fatty acid supplementation by Efamol in hyperactive children.

Thirty-one children, selected for marked inattention and overactivity, were studied in a double-blind, placebo-controlled crossover study of essential fatty acid (EFA) supplementation. Subjects received the active treatment and placebo conditions for 4 weeks each and were assessed on a variety of cognitive, motor, and standardized rating scale measures. EFA supplementation (evening primrose oil; Efamol) resulted in significantly lower levels of palmitoleic acid (a nonessential fatty acid) and higher concentrations of dihomogammalinolenic acid, an EFA previously found to be deficient in some hyperactive children. Supplementation was also associated with significant changes on two performance tasks and with significant improvement to parent ratings on the subscales designated as Attention Problem and Motor Excess of the Revised Behavior Problem Checklist. However, a variety of eight other psychomotor performance tests and two standardized teacher rating scales failed to indicate treatment effects. When the experiment-wise probability level was set at .05, only 2 of 42 variables showed treatment effects. Baseline EFA concentrations appeared to be unrelated to treatment response. It was concluded that EFA supplementation, as employed here, produces minimal or no improvements in hyperactive children selected without regard to baseline EFA concentrations.