That sounds like very interesting homework, and the results were certainly informative. Such experiments are not without risk though. IIRC there was a researcher that conducted a similar experiment -- got some volunteers with no history of mental illness go into some psychiatric institutions and fake some symptoms. The majority of them were able to get admitted with just that. The problem was getting them out afterwards. Apparently some institutions were reactant to discharge the "patients" even after they have been informed of the experiment. (I can't recall the name of the researcher unfortunately, but this experiment is described in Jon Ronson's "The Psychopath Test"). Once you're labeled as "crazy", proving that you're not can be difficult, even if your behavior does not differ from that of "normal" people.
> That's the problem with psychology or psychiatry [...] It's a complete and total joke.
Please don't group psychology and psychiatry together. The former is a legitimate field of study (whether psychology technically qualifies as a "science" is debatable), the latter, is, as you say, largely a joke (at least, in the US). Please also note that the appalling state of psychiatry today should not be taken to mean that all mental disorders are bull -- there definitely are very serious mental disorders, and people do need to seek help if they are suffering from them.
EDIT: Found the book.
The researcher was talking about is David Rosenham:
http://en.wikipedia.org/wiki/Rosenhan_experiment
Also, I was wrong when I said that the hospitals were told about the experiment -- it was a condition of the experiment that the patients needed to get out "on their own", though they didn't exhibit any of the symptoms after the initial interview, and were acting completely "normal" during their stay.