As far as I know on both sides of my extended family there is no history of substance abuse or alcoholism. One cousin who suffers from depression but that’s about it. All in all a very healthy happy low drinking bunch. My mother father and siblings all drink but within very manageable amounts.
Then there is me. Since the very first time I drank age 15 I have had an unhealthy relationship with alcohol usually drinking to get drunk. Right from the start. I am also I would say the most driven, detailed, obsessive and assertive of the bunch. So I tend to think it’s more a personality thing in my case. I guess it all depends on the individual. Whatever the reason I don’t really care. I only care that I will never drink again.