Physical & Psychologic Dependency
Physical Dependence - Where your body builds up a need for a drug
Psychological Dependence - Where your mind tells you that you need a drug
Physical Dependence is where your body needs the drug or else you will suffer from withdrawal symptoms. Physical Dependence usually appears when someone is chronically exposed to a drug, and you basically are addicted to a drug.
Psychological Dependence is where your mind is telling you that you need drugs. This Dependence is an addiction where you really cannot sleep until you get drugs because your mind will not rest until you get some drugs.