My personal prediction (mind you I don't have solid facts to back it) is synthetic emotion.
I think that the future of drugs and the pharmaceutical industry will be synthesizing human emotion into a pill, syringe, gas or whatever method they deem the most effective for whatever use they they conjure up.
One could possibly argue that the beginning of this has already started to show in that Ecstasy is sometimes referred to as the "love drug".
Possible applications would be PTSD, Depression, Mania, Crowd Control, Religion...basically everything considering that nearly every social problem could be traced back to an emotion and so an equally powerful opposite could be employed to neutralize it. Not to mention the most spectacular moments in a persons life could be, in theory, replicated. Although I'm sure this could also lead to abuse issues, I'm sure it will be no different than the difference between recreational users and those who become dependent with the drugs we have now.
then again... I could just be talking out my ass.