Drug dependance is the compulsive use of drugs despite its dangerous effects and in that condition a person needs drugs to function normally. Abruptly stopping the drug leads to withdrawal symptoms. Drug abuse can lead to drug dependence and the people who use drugs for pain relief may become dependent.
Basically there are three types of drug dependance and they are:
Physical dependence is a condition in which the body is addicted to the drug and when the drug abuse is stopped, it shows withdrawing symptoms and in some cases rapid withdrawal can be life threatening. A person requires drugs to function normally when he is physically dependent on these drugs. In most of the cases physical dependance is associated with tolerance and symptoms of the withdrawal can be terminated by re administration of the drug to the individual. Symptoms of the drug withdrawal are opposite to the effects of the drug. The intensity of with drawl symptoms in longer acting drugs is less as the body takes time to adapt to the decreasing presence of the drugs.
Psychological dependance is the process of depending on a psycho active drug for the reinforcement it provides and this is characterized by emotional and mental preoccupation with the drug’s effects and by a persistent craving for it. The symptoms displayed are not physical symptoms. Craving seems to be a common withdrawal symptom.
Cross dependance may be partial or complete. This can be understood as the ability of one drug to suppress the symptoms of physical dependence produced by another drug and to maintain the physically dependent state. Cross dependance is mostly found with sedatives and with alcohol. Generally cross dependance occurs between the drugs belonging to same family and it may also occur among the drugs of different families with similar pharmacological effects.