Are addictions hereditary?

There have been studies into an addiction gene! It was linked to alcoholism and drug addiction and other non physical addictions. I have a very "addictive family" as we have had alcoholism and drugs and also less harmful things like habitual ticks! So I do believe there may be a strong possibility that this could be the case BUT I also agree with the argument about personal choice and think it does play a part also! I guess until it is proved outright we will never know for sure!