By way of introduction I'm actually here at the site trying to understand what goes on with my b/f who has some dp problems. I am not dp/dr but I am on disability here in the US and I can give u or anyone interested some information on it.
There are two kinds of disability in the US and you get them through the social security administration, see this site: http://www.ssa.gov/disability/
The difference between the two is essentially whether you made enough money by working yet to be eligible for social security insurance benefits (SSDI) themselves. If not, you are getting 'supplemental security income' (SSI). It's less money and the rules are different. I get SSDI myself and because I used to make a lot of money before I got sick and I live in a v expensive town (new york city) I actually get almost $1200 a month. I believe that SSI caps around $600-650 but I'm not sure of this.
The deal with SSDI is that you need to apply yourself and get your doctor (I believe and MD psychiatrist not just a phD psychologist is necessary) to apply as well. Your problems must be significant enough that you do not expect to work for I think at least a year, and you have to be out of work for at least 6 months to even apply, if I recall correctly. So essentially, if you're not sick enough to not work for like at least a year then disability is not for you.
Once you are accepted into SSDI you generally are not medically reviewed again until three years later. Once accepted they will let u know when you will be reviewed and unless you go back to work u receive benefits and are not contacted until then.
With SSDI you can make up to $500 a month or so yourself and still be considered impaired; above that amount they begin counting you down and after 9 months they begin to think that you must be well again and schedule you for a medical review.
There's also this thing called a 'ticket to work'. This weird sounding thing essentially means that you can get government sponsored vocational rehabilitation services to help you get back on your feet again when you're ready. Using this, it's actually possible to get continued help while you attempt to go back to school, for example, to start a new career. Under SSDI (not SSI) you can even set up a savings program that in this weird way gives you extra money to set aside in order to start a new business or go to school. It's all very complicated but that's the kind of thing you'd have to look forward if you were actually eligibe for disability here in the US. There are these organizations called BPAO's that answer questions about disability benefits and going back to work, a list of those is at this site: http://www.ssa.gov/work/ServiceProvider ... ctory.html
You wouldn't really want to call them though until you actually have disability, but you might be able to get them to answer questions if you're curious. The one I called was seriously helpful.
Personally, being on disability, yes, has had its downsides. It's embarrassing and it is difficult to motivate when you know the bills are being paid. But if you genuinely need the time to work on recovery, it can be a life saver. I am on the road now to trying to get back to some sort of working life, after 2 years of a life dedicated to intensive therapy (and some really fulfilling and low-stress volunteer work... and being a mom!).
As to whether dp/dr is one of the disorders that qualifies for disability, I have no idea, but there is a list of them on the website somewhere as I recall. Again, my diagnosis was not dp/dr, so I have no idea.
Hope this helps; don't know what country you hail from... but to whoever might benefit: be well.