Dr Robin Cotton discusses how substance abuse doesn't directly affect DNA molecules

Student:
What is the effect of substance abuse, like alcohol and drug and depressants, to the persons DNA?

Robin:
I don't think we know the answer to that. The substance abuse can have a huge number of other bad effects but those effects probably are not on the DNA themselves. For example, alcohol abuse has a very serious effect on how your liver works and you only have one liver and if it stops working that's it. You know, you can't live without that liver.

So alcohol and drugs can affect how your brain functions and of course you only have one brain and you really need it to function well. So those things have effects on the other chemistry that's going on in your body, but it doesn't directly affect the DNA molecules.