Hard Drugs
The “hard” drugs are those that cause physical and psychological dependence, is altering the psychic and social behavior of addicts, as opium and its derivatives, alcohol, amphetamines and barbiturates.

Soft drugs
That create only a psychological dependence, among which are the derivatives of hemp, such as hashish or marijuana, cocaine, lysergic acid, better known as LSD, as well as the snuff.

This division into “soft” and “hard” is questioned by many scholars of the subject and consider that it might be suggested to her that the “hard” are bad and therefore “soft” are good or less bad and is not well as from certain doses and in the form to be administered, the “soft” drugs can have harmful effects such as “hard”.

Keep in mind that as the dose of certain drugs called “soft” can have harmful effects such as those considered “hard”.
Dependency is the state of the individual through which constantly creates and maintains a desire to ingest any substance. Please keep this wish by metabolic mechanisms and lack creates a withdrawal syndrome is called physical dependence.

If the dependency is maintained by psychosocial mechanisms, often defined as mental or psychological dependence.
From a pharmacological standpoint, drugs are divided into narcotics such as opium and its derivatives morphine, codeine and heroin, stimulants such as coffee, amphetamines, crack and cocaine, and hallucinogens such as LSD, mescaline, peyote, psilocybin mushrooms and cannabis derivatives, such as hashish.