When a person uses a psychoactive drug and the affects that drug has also depends on the person's expectations, the social setting, and cultural beliefs and value. Addiction is known to be a brain disease or disorder, which affects multiple brain functions, including those involved in sending signals for reward and motivation, learning and memory, and inhibitory control over behavior. Being that drug abuse and addiction have so many dimensions and disrupt, this is not so simple to treat. The biological theory holds that psychological disorders are caused by physiological malfunctions, for example, the nervous system or the endocrine glands often stemming from hereditary factors. The biological basis of behavior has research in the area has also contributed to our understanding of abnormal behavior. As stated "The advances in the field of behavior genetics have begun to identify specific genes that are involved in the development of complex disorders such as schizophrenia" (Gerber et al., 2003; Hashimoto et al., 2003; Williams et al., 1999) and autism (Lamb, Moore, Bailey, & Monaco, 2000; Nurmi et al., 2003).
The psychoanalytic theory was developed by Sigmund Freud and his followers who believed that behavior disorders are symbolic expressions of unconscious conflicts, which can usually be traced to childhood. People must recognize and be aware that the source of their problems usually lies in their childhood and infancy, in order for the problem to be resolved. When dealing with psychoanalysis it is designed to bring hidden feelings, fears, and unwanted motives to the conscious state so the person can overcome the problems more effectively without the use of drugs. In Freudian psychoanalysis, the client will be instructed to talk about the troubles that come to mind, with little editing as possible and without inhibiting or controlling thoughts and fantasies. The cognitive-behavioral model deals with both internal and external learning processes in the development and treatment of psychological disorders.