Their activity proves their brains were thinner before they got HIV.
Yeah, kind of a "chicken vs. egg" thing there.
Therein is a good question, one this report doesn't answer. They had 26 HIV patients and healthy 'controls.' Were the controls also risk taking gays and drug users, just lucky enough not to have caught HIV. or did the controls reflect the lower general population risk for HIV. This press report didn't specify that although the presumably scientific article on which it is based might have given that information. Based on this report alone either they've found yet another reason to avoid getting HIV or they may have finally found the long sought physical brain difference between straights and gays. Or these results may prove to be non-reproducible and irrelevant.