Something to consider is that people seek out a particular experience often to offset an existing experience or condition. Ecstasy use could have been a source

Something to consider is that people seek out a particular experience often to offset an existing experience or condition. Ecstasy use could have been a source of self-medication for the effects of depression in the folks you hung out with, rather than a cause of that depression. Like many self-medicators, they and you may not have recognized the symptoms of depression consciously before using the drug, which could lead to a misconception of cause/effect timing. But, just a thought, obviously not knowing you or them.