Long use of marijuana tied to delusions

William Atkins
Wednesday, 03 March 2010 01:51

Science - Health

According to a 2010 Australian study, young adults that regularly use cannabis (marijuana) for several years are at increased risk of being diagnosed with nonaffective psychoses, which includes bouts with delusions and hallucinations.



Nonaffective psychoses refer to types of psychosis that are not related to emotions or moods. Examples of nonaffective psychosis include schizophrenia and delusional disorders.

Researchers headed by Dr. John McGrath from the Queensland Brain Institute at the University of Queensland performed the study.

They studied 3,081 young adults who were born at a Brisbane, Australia hospital, with an average age of about 20 years, and, thus, were born between 1981 and 1984. The adults were taking part in the Mater-University Study of Pregnancy.

The result of their study is published in the journal Archives of General Psychiatry under the title 'Association Between Cannabis Use and Psychosis-Related Outcomes Using Sibling Pair Analysis in a Cohort of Young Adults' (2010;67(5); doi:10.1001/archgenpsychiatry.2010.6}.

Its authors are: John McGrath, Joy Welham, James Scott, Daniel Varghese, Louisa Degenhardt, Mohammad Reza Hayatbakhsh, Rosa Alati, Gail M. Williams, William Bor, and Jake M. Najman.

The young people were asked questions about their use of cannabis. The researchers also assessed the subjects as to the presence or absence of psychoses; specifically whether or not they had delusional behavior and/or hallucinations.

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