Fazal Subhan, Abdul Matin Khan, Ahmad Yar Sial, Muhammad Azam Zia, Haroon ur Rashid.
Drug Dependence - Neurotransmitter systems and paradigm for assessment.
Pak Armed Forces Med J Jan ;52(1):76-83.

Drug dependence/addiction is a major problem of the modern world. A substantial number of drugs prescribed therapeutically lead to abuse and ultimately drug dependence. Opiates (morphine, heroin), stimulants (cocaine, amphetamine), tranquillizers (Benzodiazepines), alcohol and antidepressants (fluoxetine, paroxetine) are some of the classes of abused drugs. Drugs of abuse mostly act as positive-reinforcers in humans as well as in laboratory animals. The rewarding/reinforcing effects of a drug are therefore frequently considered to be the primary factor in determining its abuse liability. The study of motivational effects of drugs in suitable animal models, for example place preference, conditioning, drug self administration, self stimulation & drugs discrimination, are therefore, essential to gain better insights into the neurobiological mechanisms of addictive drugs. This article presents an overview on drug dependence, neurotransmitter systems and brain areas involved in drug dependence and methods for assessing drug dependence in animal models. This is a review article.

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