Heroin is addictive in the fact that after a while you become dependent on it, and if you don't have it you get incredibly sick. I guess it the high is addictive too but if it were not for the withdrawals it would be much easier to kick.Meth is more addictive and it has barely any withdrawal symptoms other than the fact your body has been on overdrive so you need sleep, water and nutrients. That shows you how powerful it is. People fresh out of prison will have no problem risking their freedom to get high on meth, even if they know they will go back to prison relatively quickly. They consider it 'worth it.'