This one is a CNS stimulant.

https://www.verywellmind.com/adderall-for-depression-4845418

So is this

https://www.frontiersin.org/journals/molecular-neuroscience/articles/10.3389/fnmol.2021.808807/full

They're both linked to depression too. My point is that you need to get this idea of correlating the terms because of how they look similar out of your head. It's a result of drug abuse (addiction/overuse) and the consistent changes caused by that in brain chemistry, causing negative effects when they aren't affecting you. It's not a result of it being a depressant vs a stimulant that you're addicted to. A depressant, when not abused, relieves symptons of depression (and even when abused, often relieves them upon intake). Not going to get into how stimulant mania is likely caused mostly by lack of sleep, but you can look into it if interested.

And you're right that psychedelic abuse hasn't been linked to increased depression or anxiety... mostly because there's no research on it whatsoever. In fact, almost all of our studies on drug abuse and addictiveness are incredibly flawed in the first place. That doesn't make your anecdotal experience from a drug ward any more powerful tho, especially as it's going to self select for people with mania as they are more likely to both be committed by the state and by their family or friends, more likely to cause people to take notice and sit them down, etc.

Analogies are great when it's not medicine. Medicine is really fucking complicated tho. We can have a veritable chemical pathway and successful trials in animal testing and still end up with a result we shouldn't expect.

My point is not that CNS depressants don't cause depression from abuse, but that it's just a result of abusing drugs, not the fact that they're a depressant class drug.