I currently work in the drug abuse / rehab unit of a community mental health center. I'd say this job sounds like clinical experience, the degree of importance would be in line with your work duties. Would you be mainly transporting patients from place to place? Would you have any role in assessment, or treatment of the patients? This sounds like an inpatient facility so I'd imagine there's a variety of roles available.
I've massively enjoyed my time in substance abuse. I've found that the clientele varies drastically depending on the type of facility. There are some rehabs that seem to mostly accept patients with private insurance, catering more to wealthy individuals. And then there's places, where I work, that are state funded and a type of "treatment of last resort" for the uninsured. It's a rough crowd, but you grow a thick skin pretty quickly, and IMO, it's amazing patient care experience. You're working with people who have gotten a cold shoulder at many other places. I've felt very safe the entire time, save for one occasion where I assessed a patient who was psychotic and thought I was an FBI agent...even then, everything was totally fine!
