This prevalent meme image claims that mercury poisoning and autism have similar symptoms. (Presumably it is intended to imply that vaccines containing mercury cause autism, but that isn't what this question is asking.)

Mercury Poisoning and Autism Mercury poisoning and autism. It isn't a coincidence.

I want to know if the comparison here is fair. Do the symptoms of autism and the symptoms of mercury poisoning resemble each other?

  • Welcome to Skeptics!
    – Oddthinking
    Commented Jun 23, 2020 at 3:12
  • 3
    I've deleted a number of pseudo-answer and/or dismissive comments. This is an on-topic question here.
    – Oddthinking
    Commented Jun 23, 2020 at 3:12

1 Answer 1


The major symptoms of chronic mercury poisoning in children, according to the Centers for Disease Control:

  • Tremors in extremities.
  • Impaired motor control, manifesting as difficulty walking.
  • Weakness.
  • Speech impairment.
  • Personality changes (described in the study as "characterized by irritability, excessive shyness, confidence loss, and nervousness").
  • Memory loss.
  • Impaired cognitive performance.

I suppose the personality changes could include the list on that image, but it entirely omits the neuromuscular problems, which are at least as prominent. It also lumps together two very different things under "loss of speech": mercury poisoning's speech impairment shows up as difficulty forming sounds, while autism's is at the level of words and sentences.

In short, to get that list of "symptoms of mercury poisoning in children", you need to ignore about half the symptoms, and distort the other half.

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    To take this from a good answer to a great one, it would be good to include a source for the symptoms of autism that you're comparing against. In particular, the comparison of "loss of speech" is a strong rebuttal of the claim, but you don't cite specific evidence for the types of speech impairment in the two syndromes.
    – IMSoP
    Commented Jun 23, 2020 at 11:18
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    The DSM-V criteria for autism can be found at autismspeaks.org/autism-diagnosis-criteria-dsm-5 They do not resemble the mercury poisoning symptoms. Commented Jun 23, 2020 at 13:21
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    Note that motor problems are common in children with autism: pubmed.ncbi.nlm.nih.gov/31625694 (although indeed not mentioned in the DSM), so it might be helpful to get into more detail on that point with this answer.
    – Cubic
    Commented Jun 23, 2020 at 17:40

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