Yup, I did it - and loved my time there. Tons of fun, lots of learning. I'd even say that I learned more about addiction psych in my one week there than my 4 weeks of in-patient crisis psych/detox as a third-year. You basically live amongst the patients during the day, really seeing what the treatment is like. I adored it. No scut-work (unlike 3rd year med school). All learning/experiencing. Good Luck!