SAMHSA - Substance Abuse and Mental Health Services Administration Surveys: https://www.samhsa.gov/data/all-reports?items_per_page=15
Once on the SAMHSA page linked above, click on Surveys tab on left side of the page to see available survey information.
DATA.GOV - Addiction: https://catalog.data.gov/dataset?tags=addiction
DATA.GOV - Mental Health: https://catalog.data.gov/dataset?tags=mental-health
