Has a genetic basis for alcohol abuse been demonstrated?

Has it been conclusively demonstrated that a genetic predisposition towards pathological alcohol consumption exists in some individuals, or is this still theoretical? I’ve always been led to believe that alcohol abuse has been shown to have a confirmed genetic basis, but somebody recently mentioned here (can’t find the thread) that this is still open to conjecture. I’m going to go out on a limb here and predict that almost all knowledgeable replies to this question will center on a diathesis-stress model—that alcohol abuse has both genetic and environmental causes, but what are the prevalent theories right now on this subject?

I don’t know where to find these studies, but I have read the conclusion from studies that looked at foster/ adoption kids - both kids with non-alcoholic biological parents being raised in alcoholic homes, and kids from alcoholic biological parents being raised in non-alcoholic homes - and found a higher rate of kids with alcoholic parents becoming alcoholics themselves even if raised in non-alcoholic homes than kids from non-alcoholic parents in similar homes. So there seems to be some genetic weakness or suspectability to become alcoholic, or more generally, to become addicted to some substance.

The raised percentage was nowhere near a clean-cut 100% or so - IIRC (and the memory is fuzzy), the rate for normal kids (comparision) was about 30%, and for kids with alcoholic biological parents, the rate was about 50%.

There’s also some speculation in the medical community from what I’ve read at layman’s level that the “addictive personality”, that is, a person suspectible to becoming addicted to something, whether alcohol, drugs, or online gaming, is sometimes caused by a chemical imbalance - either hormones or neurotransmitters - with regards to pleasure. Maybe the serotonin level is wonky, so they have a hard time feeling pleased without help.

(Another possibility, and given the huge number of people who are addicted to some substance - alcohol, tobacco, illegal drugs - it’s probable to have more than one cause, is the weak personality, based on bad parenting/ influences in childhood).

This would also fit with what some of the medical dopers explained in other threads: that some people with mental illnesses like schizophrenia, depression, anxiety, or similar (which can also partly be traced to hormonal imbalances) unconciously self-medicate themselves with alcohol or Marijuana, because the effects are crudely similar to what good medication would also do and bring a bit more balance to their body chemistry.

Hopefully, one of the medical Dopers with expertise in this area will be along to give more details and a fuller explanation.

Here’s a nice little article which lays out some of the evidence for the genetic basis of alcoholism, along with references: Genetic and Environmental Influences on the Development of Alcoholism

Genetic susceptibility may be due in part to inheritable alterations in just how alcohol is metabolized.