It can be found in DNA, for ex. my parents have a history of addiction then had me , so I have addiction in my blood which gives me a highter risk of getting addicted
other than it being in your DNA like the person above my comment said, it could also be that you use drugs at a younger age which can develop problems when you are older since your brain isn’t completely developed yet until you are 25. another reason that it is likely for you to have addiction problems Is if you take a lot of pain medication Because you become addicted to that relief
