Seems like every time I pick up the newspaper or go to a web news site there is an article about someone running around naked and exhibiting some additional form of weird behavior. Is this becomming more common? Is it related to meth use?
Probably.
Years ago, people would have said LSD.
Those drugs can trigger psychotic reactions.
Other, less likely possibilities: dementia, schizophrenia, bipolar mania, brain tumor.
PCP (Angel dust) is still around as well.