Still figuring this out.. does anybody know if it could have been the drugs that gave me panic disorder/depersonalization, how long I would have these symptoms for, wouldn’t they be getting better by now? It’s been 13 years since!
I'd have no conclusive way of saying whether your experiences with drugs lead to that, or not. But, here are my $0.02 on the matter:
Having been deeply involved in the psychedelic drug scene back when I was in university (been done doing shit like that for a long time now), in my very anecdotal observations, it seems people generally tend to "get over" intense experiences like that, from tripping. It can take a lot of time for some, but, if you've been feeling DP and panic disorder, and it's 13 years later, I think it is very, very unlikely that it's from your drug use, rather than your abuse.
I've had my own experiences with drugs, that were -extremely- intense, and made me have repeated depersonalization for a while. Basically, an acid trip (with nitrous oxide balloons now and then), made me have an extremely intense experience that involved depersonalization/derealization. It was just, so intense. No point really describing it. Point is, after that trip, I started to randomly enter depersonalization/derealization. It would happen sometimes if I was just thinking of the right stuff. Or, if I used weed, I would enter it. Alcohol could make me enter it. But yeah, just sitting there could make me enter it. I didn't know what it was. I didn't know it was a dissociative state. I didn't know jack shit about that stuff back then.
I don't wonder whether my present occasional derealization and depersonalization is related to it, though. As time went on, the acid-induced DR/DP went away. It just stopped happening eventually, happened less and less with time, until it entirely stopped happening. This took a while, but it didn't take more than a year I think.
That's my own experience with drug-induced dissociative states. Just an anecdote.