Year: 2011
Type: article
Abstract: Although substance abuse disorder is a common comorbidity of mental illness, it is particularly prevalent in patients with schizophrenia. One of the most widely held explanations for this phenomenon is the self-medication hypothesis which is based on the negative reinforcement theory; that is the behaviour is reinforced by the purposeful removal of aversive experience, which could be disease symptoms and/ or side effects of the medication. However recent studies on the neuropathology of schizophrenia and addiction behaviour have provided an alternative hypothesis. It has been suggested that there is a common neuropathological substrate independently causing the manifestation of symptoms of schizophrenia and addiction disorder. There are substantial literature suggesting that the mesolimbic dopamine (DA) system is a major substrate for reinforcing effects of substance and involving in mediating drug craving. The mesolimbic DA system is also an important system involved in the neuropathology of schizophrenia. In fact, studies of pharmacological models of psychosis using different psychoactive substances have provided further evidence on this hypothesis and also improve our understanding of the biological basis of psychotic symptoms and the disorder as a whole. This article aims at providing further understanding of the dopamine hypothesis of schizophrenia through brief discussions on two commonly studied pharmacological models of psychosis – Amphetamine and Ketamine.
Author: Sherry Kit Wa Chan
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2160716218