Addiction and dependence

Addiction is a physical or psychological need to keep using a substance — such as alcohol — to a degree that becomes harmful, and it can be personally destructive, costing an addict their job, home, money, friendships and family relationships over time. Repeated use of drugs or alcohol raises the tolerance of the body's receptors, so they respond only to progressively higher doses, driving greater intake and deeper addiction.

This produces two forms of dependence. Psychological dependence is a mental 'hooked-on' state in which the user is preoccupied with, and craves, the drug — a state described as euphoria, characterized by constant mental and emotional focus on the substance. Physical dependence is a state in which the body itself requires the drug's continued presence; if intake is abruptly stopped, the body 'protests' with withdrawal symptoms ranging from mild tremors to convulsions, severe agitation and fits, depressed mood, anxiety, nervousness, restlessness, irritability, insomnia and dryness of the throat, depending on the drug involved. …