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March 6, 2014

Marla Augustine, Communications and Legislative Services, (402) 471-4047 or 

DHHS: Marijuana Negatively Affects the Brain

March is Brain Awareness Month
Lincoln—Despite the legalization of medical and recreational marijuana that has occurred in some other states, the drug is not harmless, according to two directors in the Nebraska Department of Health and Human Services.
“There is a national discussion going on about marijuana,” said Scot L. Adams from the Nebraska Department of Health and Human Services.  “Part of that discussion is focused on the consequences of the drug.”
It’s an important discussion to have in Nebraska, he said, because 12 percent of 12-to-17-year-olds and 26 percent of 18-to-25- year-olds in the state use marijuana.*
Developments in brain science indicate that smoking or ingesting marijuana is associated with alterations in brain structure, function and behavior.
A number of studies have linked chronic marijuana use and mental illness. High doses of marijuana can produce a temporary psychotic reaction (involving hallucinations and paranoia) in some users, and using marijuana can worsen the course of illness in patients with schizophrenia.  A series of large studies showed a link between marijuana use and later development of psychosis.  Associations have also been found between marijuana use and other mental health problems, such as depression, anxiety, suicidal thoughts among adolescents, and personality disturbances.
Marijuana can affect brain development. When it is used heavily by young people, its effects on thinking and memory may last a long time or even be permanent. A recent study of marijuana users who began using in adolescence revealed substantially reduced connectivity among brain areas responsible for learning and memory.
A large long-term study in New Zealand showed that people who began smoking marijuana heavily in their teens lost an average of 8 points in IQ between age 13 and age 38.  And the lost cognitive abilities were not fully restored in those who quit smoking marijuana as adults.
Marijuana is also unsafe if you are behind the wheel. It is found in the blood of around 14 percent of drivers who die in accidents, often in combination with alcohol or other drugs.
“Marijuana affects skills required for safe driving, like alertness, concentration, and coordination.  It makes it hard to judge distances and react in time,” said Dr. Joseph Acierno, the state’s Chief Medical Officer and director of the Division of Public Health. “And combining marijuana with drinking alcohol increases the danger.”
Someone who smokes marijuana regularly may have many of the same breathing and lung problems that tobacco smokers do, he said, such as a frequent cough, and a greater risk of lung infections like pneumonia.  It’s unclear as yet whether marijuana smoking causes lung cancer.   One study found that smoking marijuana may increase the risk of heart attacks.
“It’s important we understand the potential effects of marijuana, especially on adolescent and young adult brains, because the brain is still developing and the impacts can be serious,” Adams said.  “We also need to know more about the health effects.  More research needs to be conducted to understand the consequences of using marijuana.”
March is Brain Awareness Month.
*According to the National Survey on Drug Use and Health, 2011 and 2012, Substance Abuse and Mental Health Services Administration.  See Table 2 at