I think they changed the name to cover the addictions and other clear-cut "behaviors" that they have tried and true plans for and know how to treat, etc.; insurance companies know what to do with them, can classify them or the government has people in the legal system, public health system, those with serious/chronic mental illness, etc. It's a government/insurance thing.

Back in the early 1970's when I started therapy I had to go to the Department of Mental Hygiene Talk about feeling dirty, LOL.