They used to say that about Abilify, before Abilify went generic and now they justify the $$$ for Latuda in part by saying its amazingly weight neutral. Here's the thing...

with the exception of molindone, which sometimes causes minor weight loss, just about any antipsychotic/neuroleptic/tranquilizer can cause some degree of weight gain. Its worse with some of the atypicals (clozapine and zyprexa come to mind) than with many of the older, "conventional" agents, but the old ones could cause weight gain, too.

I don't know what to tell you, honestly. The other problem is that everybody takes multiple medications these days. Even if a given drug doesn't cause weight gain by itself (in most people), nobody has a really good idea of what happens when you're on other drugs at the same time.

I hope things get better for you. :-)