The link between fish consumption and neurobehavioral abnormalities in adults is likely related to mercury toxicity.
Nota del Doctor
For other videos on the health risks associated with mercury, see:
Mercury vs. Omega-3s for Brain Development
Hair Testing for Mercury Before Considering Pregnancy
Nerves of Mercury
How Long to Detox From Fish Before Pregnancy?
Fish Intake Associated With Brain Shrinkage
Pollutants in Salmon and Our Own Fat
And check out the companion video, Maternal Mercury Levels, on mercury poisoning from maternal fish-eating.
For more context, see my associated blog post, Mercury Testing Recommended Before Pregnancy.