This paper will discuss the relationship between two commonly abused recreational drugs and schizophrenia. Cocaine and marijuana are two of the most commonly used drugs in the country, and have very different effects on brain function.
In a periodical on marijuana and psychosis1, the main topic is whether or not THC, the main psychoactive ingredient of marijuana, can even cause schizophrenia or any other type of psychosis. It seems that there have been very few studies which have linked marijuana use with psychosis, although there seems to be a correlation between the use of marijuana and occurrence of psychosis. This correlation is likely to do the use of drugs whose use is linked with marijuana use, amphetamines in particular. "If cannabis-induced psychoses exist, it seems that they would require very high doses of THC [tetrahydrocannabinol], the prolonged use of highly potent forms of cannabis, or a pre-existing vulnerability", Hall suggested. Cannabis might have a causal link with psychosis in vulnerable people [eg, adolescents and young adults], he said, but the nature of this vulnerability has yet to be identified It is unclear whether this means that cannabis precipitates schizophrenia, whether it is a form of self-medication [of an existing psychosis], or whether the association is because of the use of other drugs, such as amphetamines, which heavy cannabis users are more likely to use."1 The author then goes on to say that there is more evidence that suggests that THC alleviates the symptoms of schizophrenia, not causes them.
Cocaine, on the other hand, seems to be strongly linked with schizophrenia. An article on the relationship between cocaine and the symptoms of schizophrenia2 shows how cocaine users can experience symptoms of schizophrenia. This link supports the popular theory that schizophrenia is caused in part by a problem with the brain's balance of dopamine.
