That is soooooo stupid. I’m pretty sure there are not big difference between gay people and straight people on these issues.
I can see there being ETHNIC differences, even maybe SEX differences, but not sexuality differences.
Substance abuse happens more often then you would like to realize among homosexual individuals. Same harmful effects, sure, but the NIH is simply complaining that a disproportionate number of smokers are homosexual. Which IMHO, is a matter of Doctor Obvious, given what I have seen among the homosexual individuals which I know.