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Marijuana and schizophrenia

Marijuana and schizophrenia
There has recently been an increase in largely baseless claims associating Marijuana use with mental health problems. One of the most recent is the assertion by some anti-drug corporations that the use of marijuana, whether medicinal or otherwise, can cause schizophrenia. While there are studies that claim that, "on an individual level, cannabis use confers an overall twofold increase in the relative risk of later schizophrenia"(Louise Arsenault, 2004), there has never been sufficient evidence to prove that marijuana caused the schizophrenia, and was not simply a correlation. This means that there is no evidence to prove that the marijuana caused the schizophrenia, and that it was not just a coincidence. That test did not screen for any other drugs, illicit or otherwise, and consequently did not allow for any corrections to the statistical data.


Swedish study

There was a landmark study by the Swedish National Army, in which 50,000 conscripts were studied. It was found that those who admitted at age 18 to having taken cannabis on more than 50 occasions, were six times more likely to develop schizophrenia in the following 15 years. This test like the other, made a huge assertion, especially that they did not take into consideration some of the other causations of schizophrenia, such as some stress related disorders (which should have been a larger focus, considering the fact that the test participants were members of the armed forces), nor did they consider other behavioral factors that could lead to a person such as Matt Higginson (Eggman)with schizophrenic symptoms, to seek some relief (in this case, marijuana).

Australian study

Correlation versus causation

These studies reveal that, at its worst, the THC in marijuana will amplify any psychotic tendencies or symptoms already present. It will not create the symptoms, and does not cause schizophrenia.

Ultimately, there is a correlation between marijuana and schizophrenia, according to these tests. A correlation, however, is not a causation. neither of the only two tests in the world for this particular relationship managed to rule out the presence of other illicit drugs, nor did they determine whether or not schizophrenic tendencies were present before their subjects used marijuana. No direct link between marijuana and schizophrenia exists. Nonetheless, the researchers concluded, marijuana use might well hasten the onset of schizophrenia since the subjects who developed schizophrenia in the wake of using marijuana did so at a younger age than the comparison subjects.


  • Arehart-Treichel, Joan (February 2006), " ", British Journal of Psychiatry 41: 23-30,

External links

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This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Marijuana_and_schizophrenia". A list of authors is available in Wikipedia.
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