Moral of the story: Anything that could simulate FTD would be temporarily would be one hell of a drug.
It's going to take more than a handful of cherry-picked anecdotes to convince me that this condition really exists.
There are a several similar examples in Oliver Sacks' Musicophilia. It provides some explanations, too.
Wake me up when somebody has a means of inducing the condition that they can show is more reliable than a placebo.
These conditions appear after seriously traumatic incident, generally. The fact that we cannot double-blind test them doesn't mean it doesn't exist. There /is/ a correlation with some physical brain alterations.