They're self-medicating, exactly.
We suspect that there are many people walking around who are in the justice system because of their substance abuse. They have been drunk driving, and have been fired from their jobs for their substance.
Is there a concerted effort, as part of your education of health care providers, to say that if there's a substance problem of any sort, one of the first things you should look for, in addition to treating the substance abuse, is an underlying mental illness?