Just because a medication is "for" something... Doesn't mean that it works that way on everyone.
Case in point: I'm ADHD. That means that -almost universally- stimulants act as depressants on me. From 8shots of espresso being the perfect bedtime drink, to extremely potent things like cocaine & amphetamines making me very, very calm/mellow. Meanwhile if someone without ADHD slams back espresso or stimulants? They're awake-awake-awake!!! Jitter. lol. I still don't quite grok that. Just because I've never experienced it.
With mind/mood altering drugs in Rx land? It gets even more complicated, because if a company already has a best selling anti-depressant, and they develop another one? They don't compete against themselves. They'll sell it as an antipsychotic (or anti anxiety med, or whatever, anything 'similar'). even if it's a lousy antipsychotic, and a stellar antidepressant.
So not only do you need to generally
- Ignore what it's "for" / does for most people
- Ignore what it labeled as
Because there will always be a percentage of people who respond in the opposite manner, and meds that are best used "off-label".
If a sleep med keeps you up? It's not a sleep med. For you. Talk to your doc. They won't know it's not working unless you tell them.