Potential Link Between Dietary Intake of Fatty Acids and Behavior: Pilot Exploration of Serum Lipids in Attention-Deficit Hyperactivity Disorder

Essential fatty acids are structural components of all biological membranes and form the environment for membrane receptors, ion channels, and enzymes. Dietary linoleic acid is metabolized by delta-6-desaturase to gamma-linolenic acid (GLA). Through several further metabolic steps, GLA is eventually converted to series-1 prostaglandins, thromboxanes, and other molecules involved in regulating the moment-to-moment function of various physiological processes. For example, prostaglandins interact with dopamine neurotransmission. The biochemistry and physiology of essential fatty acids are reviewed, with attention to possible implications for behavior. Delta-6-desaturase deficiency has been hypothesized to be one cause of attention-deficit hyperactivity disorder (ADHD). To explore this possibility, we examined the correlations of serum lipids and behavior in a double-blind crossover comparison of GLA, d-amphetamine, and placebo in 16 boys (ages 6-12) with ADHD. Looking at the fatty-acid components of serum triglycerides across treatment conditions, we found that higher scores for behavior problems correlated with lower levels of GLA (for each of four behavioral ratings, p < 0.015) but not with its precursor, linoleic acid. This is compatible with a metabolic bottleneck at delta-6-desaturase being related to some ADHD symptoms. These preliminary findings are consistent with the possibility that fatty-acid intake or metabolism may influence behavior, at least in children with ADHD, and could conceivably modulate the effects of psychopharmacological treatment. This study must be considered exploratory and heuristic, and more definitive studies are needed to examine the possible relevance of fatty-acid metabolism to psychiatric disorders.