Standardized mean differences in ADHD-related symptoms in omega-3 PUFA-treated compared to placebo-treated subjects. SMD are the standardized mean differences (scaled to standard deviations) in the change-from-baseline scores in the placebo and treatment groups, along with 95% confidence intervals. A summary of each study's characteristics can be found in Table 1. Because of the incomparability of the instruments used in several of the studies, we were only able to include three studies in this summary. We have shown separate estimates for hyperactivity and inattention subscales, as well as distinguished parent and teacher ratings. There are not yet sufficient sufficiently comparable data to justify calculating an overall summary. We have, however, provided preliminary inverse-variance-weighted averages of the two studies in each subsection.