22-Year Long Study Finds Marijuana Has No Effect on Physical or Mental Health

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A study published in the Psychology of Addictive Behaviors journal found no long-term health effects associated with marijuana use.

Researchers at the University of Pittsburgh Medical Center and Rutgers University began the study in the late 1980s, and used then-14 year old males drawn from Pittsburgh public schools. Four groups were tracked until 2009 and 2010, when the participants were 36 years old.

The groups were divided as follows:

1. Marijuana non-users (46%)
2. Early chronic users (22%)
3. Late-adolescent users who continued use (21%)
4. Adolescence-only users (11%)

The study found no statistical change in physical or mental health among any of the four groups between the beginning and end of the research period. Even without controlling for other factors, chronic users did not have a worse health prognosis than individuals in the other groups.

The researchers noted that the study does not have the final word on marijuana’s long-term effects, and that more research needs to be done regarding cannabis’s intellectual and cognitive effects.



Photo Credit: ashton


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