And some patients were told that the pain was not real, that they were just imagining it or that that they had mental problems.

VOA: special.2011.07.26

The disease causes sleep disorders, mental confusion,personality changes, speech problems,seizures and coma.

VOA: special.2010.01.04

"The problem with that body of research is that it's difficult to interpret because obviously people with existing mental health problems use cigarettes to self-medicate."

VOA: standard.2010.06.15