I have heard the same thing (wrongly) said of Van Gogh, whose poor mental condition towards the end of his life was almost certainly caused by syphilis.

This is not to underplay the impact of poisonous paints: the entire cadmium range (cadmium red and yellow), Naples yellow ( lead antimonate), Flake white (lead again). For more horrors, check out the book artist beware.

Looking at the article you linked, the evidence for Caravaggio's death by lead poisoning does indeed seem conclusive. However, IMO it almost certainly was not through the use of paint itself, but from the careless manufacture of paint. In those days, most painters made their own paint by mixing powder pigment with oil. Powdered lead pigments is 100 times more dangerous than pigment locked into an oil emulsion.

A dear artist friend of mine died as a result of their art. God bless you Jim where ever you are.