Can mercury cause attention deficit disorder?

Mercury & ADHD: High mercury levels in the blood was found to be associated with add, according to study from hong kong, where consumption of deep sea fish is high.

Possibly, but...: Mercury poisoning can cause a variety of physical problems and behavioral and mental changes, some of which may look like adhd. However, it is not a "cause" of adhd, even though there may be many overlapping symptoms. Any heavy metals, lead being the most common, can cause mental changes that look like adhd. Adhd is a chronic disorder probably present from birth.