Children who use marijuana before age 12 are twice as likely to later develop serious mental illness as those who don't try the drug until they're 18, according to a federal report released Tuesday.
Bush administration officials pointed to the study as growing evidence that smoking marijuana may cause mental illnesses -- including depression, schizophrenia, and suicide attempts -- in some people.
But while the association of drug abuse and addiction with mental illness is well known, a causal connection between marijuana smoking and psychiatric disorders is not clear, other experts say.
In Tuesday's study, 21% of people who reported first using marijuana before age 12 also reported that they later went on to develop signs or symptoms of a serious mental illness. Those who said they used the drug only after age 18 had a 10.5% chance of reporting similar problems.
The study was based on federal drug use data culled in 2002 and 2003. Other past studies publicized by federal officials Tuesday also point to a connection between marijuana use and the development of mental problems later on.
"New research being conducted here and abroad illustrates that marijuana use, particularly during the teen years, can lead to depression, thoughts of suicide, and schizophrenia," said White House Drug Czar John P. Walters. "This press conference is a public health warning."
Another study highlighted by officials, published in 2001, suggested that people who were not depressed but used marijuana were four times more likely to develop depression years later than those who never used the drug.
Researchers have long observed a connection between drug use and mental illness. Many studies show the simultaneous occurrence of mental illness and substance abuse. People with mental illnesses are also known to use drugs to lessen their symptoms, a phenomenon psychiatrists refer to as "self-medicating."
But federal officials and some researchers say evidence is accumulating that shows that marijuana can actually cause serious mental illnesses in otherwise well people.
According to the National Institute on Drug Abuse (NIDA), depression, anxiety, and personality disturbances have been associated with marijuana use. However, the NIDA says it is not known whether marijuana use is an attempt to self-medicate an already existing mental health problem, or whether marijuana use leads to mental disorders (or both).
"The evidence is collectively indicating that there is a causal connection," says Neil McKeganey, PhD, professor of drug misuse at the University of Glasgow in Scotland.
McKeganey notes that scientists have not yet uncovered evidence linking marijuana use to the brain changes routinely seen in people who suffer from mental illness. "If we wait until we understand that mechanism, we will lose thousands of young people," he says.
But Paul P. Casadonte, MD, a psychiatrist and associate clinical professor at New York University, cautions in an interview that research is not yet strong enough to show a causal link between marijuana use and serious mental disorders. He suggests that such claims by Walters and other administration officials were intended to further the Bush administration's efforts to quell young peoples' marijuana use.
Also, what you guys don't realize is that Marijuana is not a gateway drug in the Government's eyes. In said eyes the Government considers Marijuana to be a level 1 drug in the Controlled substances act. Amphetamines like meth are a Level 2 drug. Level 2 is LOWER than level 1. Why? Because Marijuana was used in the late 50s ,60s and 70s by "Hippies" Previous to this marijuana was REQUIRED to be grown on a subsistence farm, The reason is that Hemp actually increases the strength of farm crops.(https://www.globalhemp.com/2001/01/he...n_253348.html) Hemp is also used heavily in Indian culture as a medical plant. Why should it be illegal in your eyes?
Studies have shown that marijuana has caused the majority of lethal car crashes, and the substance is highly addictive. 95% of people who use marijuana will move on to hard core drugs like PCP, meth, crack cocaine..etc
It causes lung cancer, promotes domestic violence, lose of brain cells, gateway drug, and many more harmful factors, and these stupid pot heads still think its nothing bad
Marijuana does not cause lung cancer. The tar inside of it does, which is a result of smoking anything and breathing it in. There are ways of stopping this by not breathing it. Domestic violence by Marijuana? Loss of brain cells has been disproved. ( Solved: Why pot smoking causes memory loss - CBS News )
"Stupid pot heads" marijuana: History of Marijuana Use — Infoplease.com