Abuse of any psychoactive drug on the regular leads to depression.
That’s a biased generalisation.
While abusers of psychedelics are rare, they’re generally manic and psychotic moreso than depressed.
Yes, depression can be caused by any addiction and abusing stims can cause a lack of neurotransmitter due to exhausting the resources for the body to do so.
It’s a bit different than using something that’s a direct depressant though.