You sir are an idiot, if you decided to to read the whole thread you would see where I got that excerpt from.
In terms of risk to your pysical health the risk is absolutely none. It will cause no physical brain changes whatsoever. But, in terms of mental health, escaping to a different reality and messing with your perception of the world around you in a large way on a regular basis will probably cause an unknown amount of emotional/perceptional trouble.