SSRIs are drugs like Prozac, Paxil, and Zoloft. MILLIONS of people take these drugs in America alone. I have never heard of them giving a false positive and due to the enormous volume of people that take these drugs, if one did it would be CNN headline type news AND all the drug testing companies would immediately have to adjust their tests so it would not happen.

Given all that I find it VERY hard to believe that the SSRI would have anything to do with a false positive. It would most certainly have to be something else your friend eats or takes that is causing it.