In the world of addiction there is something called the "addiction cycle". It begins with a trigger and leads to full-scale addiction.
Perhaps the trigger in an addiction cycle is some kind of emotional pain -- a death in the family or a broken romance. Or maybe you are having problems at work. It could be a physical problem, like debilitating pain.
This individual is basically a good person who has trouble dealing with the difficulty they are experiencing. He or she may be unable to resolve or confront the problem, and see their present situation as hopeless and unendurable.
While everyone has experienced similar situations like this from time to time, the difference between addicts and non-addicts is that addicts turn to drugs or alcohol as a way to resolve their problems or discomfort.
The cycle begins
Thus the addiction cycle begins. Initially you feel better, the drugs "taking the pain away." But then you come to rely on the drugs and cannot stop taking them. Suddenly you are addicted.
This is when your behavior starts to change. In order to keep your addiction secret from your friends and loved ones, you may withdraw from them. Or you may start treating them poorly.
As your life spins out of control, all you care about is drugs -- how to get them, when you are going to take them next.
You may realize you have a problem and decide to manage things on your own. "I'll cut back." This could work, but it's unlikely. The next step is to break the addiction cycle completely and seek treatment.
This is a vicious cycle and treatment from experts is the only way to break it.