QuietStorm
Ashes, ashes, we all fall down
It's just one possibility of many. She could have just started recently, who knows?I've seen that episode so I know what you're thinking of, but I think if Casey had an addiction to inhalants, you would have heard about it in the documents from her friends. as you could tell from that episode, that's not the kind of addiction you can hide easily - when that woman spoke, she sounded severely mentally disabled, IMO.