The coexistence of both a mental health and a substance use disorder is referred to as co-occurring disorders.
Links
[1] https://www.samhsa.gov/disorders/co-occurring
[2] http://rethinkpot.org/tags/mental-health
[3] http://rethinkpot.org/tags/co-occuring
[4] http://rethinkpot.org/tags/substance-abuse
[5] http://rethinkpot.org/tags/samhsa