Just my experience. I'm a recovering crack addict. My stepmom is addicted to pills..anything that will make her numb; other family members addicted to varying substances.
Went to al-anon as I was not doing well with all the dysfunction around me. I spoke to someone at the meeting (after the meeting) about why I was there, and was I still welcome when "my" A's are addicted to drugs.
He laughed, gave me a hug and said "sure...I'm here because my son is addicted to crack". The substance was never mentioned, the behavior (on both sides) was.
I understand about drugs being illegal, but my stepmom gets her's legally from her doctors.
I do hope you find a good supportive group.
Hugs and prayers,
Amy