Why do some people become addicted, while others don’t?
Great question, and a hard one. We don’t fully understand yet why this is so. We know that genes play a part, because an inclination for addiction can run in families, and because different strains of mice, rats, and other animals differ in how readily they develop addiction-like behaviors after they’re exposed to drugs.
We also know that a person’s environment plays a part in addiction. For example, what are the factors that encourage someone who has tried a drug to keep on taking it to the point where they can’t stop? Many scientists are trying to untangle the answers so that we can find better ways to prevent and treat addiction.