On Why alcoholism is not a disease, I have shared a study indicating the highest risk for drug dependency being among people whose blood type is AB negative. For example:
the blood type AB- had a frequency of 12.4 times more than B+ among the addicts.
The probability rate of AB negative blood type compared to other blood types among the addicts was 6.07 fold the control group.
None of this is to function as an excuse for any sort of behavior. Remember:
For an effective and compassionate societal response to problem drinking, the disease model of alcoholism should be replaced by a social learning perspective.
Drinking and drug use are both falling under the umbrella of drug use. But why would there be a difference between A negatives likelier to be heavy drinkers and AB negatives heavy drug users? In this case, the blood type personality model might serve with answers:
Rh Negative Blood Type Personalities
I am trying my best to explain it in this video:
See my YouTube channel for part 2.