A drug abuser undergoes several stages
Stage one: Tolerance
A person starts abusing drugs for the first time and more into habitual use where the drug takes the central stage of hi/her life. This repeated use leads to changes in the brain and nervous system so that the user needs more of the drug to get the expected effect
Stage Two: Dependence
The body of the drug abuser demands that he takes more drugs. The abuser is now in the stage of psychic or physical compulsive desire to continually use the drug, either to experience the desired effects or avoid the consequences of withdrawal. The suffering from withdrawal is like an emotional prison trapping the drug abuser.
Stage Three: Addiction
The user is now a victim of drugs and cannot help himself or herself. He/she has now developed physical and psychological need for the drug for the body to function normally. This may lead to damage of vital organs in the body such as lungs, liver, central nervous system etc. and the work output may deteriorate
The user lives in denial and has little concern for future life. The use may manipulate other people to get what he/she wants so as to maintain the habit.