Hi there. Well the difference between psych and disability is sometimes a fine line. Psych patients can have dd and disability clients can have psych disorders, hence a dual diagnosis. In dd you will be dealing with people who have numerous syndromes and disorders aquired genetically or environmentally or otherwise, from autism to fragile x. Clients can present challenging aggresssive behaviours at one end of the spectrum and are living in communities with good life and social skills in the other. I have little experience of psych but can tell you that both specialities deal with long term care and an emphasis on improving the persons quality of life by improving independance and creating stability in their lives so that they can better integrate into the community. Good luck.