Dopamine and Addiction - What's So Hard About Addiction?

Scientists have found that when rats are exposed to different reinforcing substances and behaviors, they have different increase in dopamine firing. And of course, anything that increases dopamine firing is something that our brains then get the message, you should get more of that,. That's good,get more of that. But it's so hard about addiction is that what happens is that our brain then confuses something that we need for basic survival with something that we really should avoid.