NIDA & the Facts on Marijuana

The National Institute on Drug Abuse Offers the Facts on Marijuana


From the website:



Use is rampant:

“Marijuana is the most common illicit drug used in the United States.”

brain damage

Has a powerful effect on the brain:

“Marijuana overactivates the endocannabinoid system, causing the high and other effects that users experience. These include distorted perceptions, impaired coordination, difficulty with thinking and problem solving, and disrupted learning and memory.”

Interferes with successful lives:

“Heavy marijuana users generally report lower life satisfaction, poorer mental and physical health, relationship problems, and less academic and career success.”

Damages the brains of young people:

“Research from different areas is converging on the fact that regular marijuana use by young people can have long-lasting negative impact on the structure and function of their brains.”

Permanently lowers IQ:

“A recent study of marijuana users who began using in adolescence revealed a profound deficit in connections between brain areas responsible for learning and memory. And a large prospective study (following individuals across time) showed that people who began smoking marijuana heavily in their teens lost as much as 8 points in IQ between age 13 and age 38; importantly, the lost cognitive abilities were not restored in those who quit smoking marijuana as adults.”

Causes heart disease:

“Marijuana raises heart rate by 20-100 percent shortly after smoking; this effect can last up to 3 hours. In one study, it was estimated that marijuana users have a 4.8-fold increase in the risk of heart attack in the first hour after smoking the drug.” 

car wreck

Causes car wrecks:

“A recent analysis of data from several studies found that marijuana use more than doubles a driver’s risk of being in an accident.”

Damages the lungs:

“People who smoke marijuana frequently but do not smoke tobacco have more health problems and miss more days of work than nonsmokers, mainly because of respiratory illnesses.”

Causes psychiatric illness:

“A series of large prospective studies also 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.”


Damages babies:

“Marijuana use during pregnancy is associated with increased risk of neurobehavioral problems in babies. Consequences for the child may include problems with attention, memory, and problem solving.”


Is NOT a legitimate medicine:

“The FDA requires carefully conducted studies in large numbers of patients (hundreds to thousands) to accurately assess the benefits and risks of a potential medication. To be considered a legitimate medicine, a substance must have well-defined and measureable ingredients that are consistent from one unit (such as a pill or injection) to the next.”

Is definitely addictive:

“Contrary to common belief, marijuana is addictive. Estimates from research suggest that about 9 percent of users become addicted to marijuana; this number increases among those who start young (to about 17 percent, or 1 in 6) and among daily users (to 25-50 percent).”

And is more potent that ever:

“The amount of THC in marijuana samples confiscated by police has been increasing steadily over the past few decades.”

Read more:

drug facts week

12 thoughts on “NIDA & the Facts on Marijuana

  1. Dear Good LinkedSamaritINs,

    Kentucky’s legislative session is in full swing. If you live in Kentucky, please call your legislators. The Kentucky Legislative Hotline is (800) 372-7181

    You can also find YOUR Kentucky legislators at:

    Tomorrow (Tuesday) Louisville physicians will meet with legislators.
    So if you can call today, that would be ideal.

    Two issues of note are:

    (1) The Good Samaritan Drug Overdose Law;


    (2) Legalization of Medical Marijuana

    I am in favor of (1) and opposed to (2).

    I am NOT opposed to using the chemical in marijuana (THC) for medical purposes. But more research needs to be done before other forms (e.g. “smoking”) of this drug can be deemed safe. First do no harm.

    FYI, marijuana is ALREADY legally available in prescription pill form.

    Here is a Mayo Clinic opinion on medical marijuana:

    This is a Courier-Journal article on the medical marijuana debate:

    Please let YOUR opinion be heard at (800) 372-7181.

    – Thanks,

    James Patrick Murphy, MD, MMM is board certified in Pain Management, Addiction, and Anesthesiology. He is the Medical Director of Murphy Pain Center, an Assistant Professor with the University of Louisville, serves on the board of the International Association for Pain and Chemical Dependency, and is President of the Greater Louisville Medical Society.

  2. Time Magazine article about the effect of marijuana on the developing adolescent brain:

    Confluential Truth Tweet on January 30, 2104
    #Marijuana may seem “cool” but it’s not cool to damage your still developing adolescent brain #drugfactsweek

    • At 12 years of age my dyslexic son had a written IQ of 129 and a verbal skill of 15 years of age. At 13 years of age, my son fell into a group of less than wonderful guys and started smoking cigarettes and marijuana. Needless to say, none of my pleadings or threats made any difference. His friends and being cool was more important than anything I had to say. He continued on that path and never finished high school or ever accomplished anything of real value. He is now 44 and unemployed. One of his main concerns is where he will make his next “purchase” and how he can get the money to make it. He is not a criminal nor has ever hurt anyone; but as long as he continues to smoke, he will never have the ambition to do anything but what he has always done. So I can tell you that for certain….marijuana is not harmless. It ruins lives.

      Murphy’s Warrior 🙂

  3. If you’ve lost TIME Magazine, you may have lost the war… to legalize marijuana.

    Adverse Health Effects of Marijuana Use
    Nora D. Volkow, M.D., Ruben D. Baler, Ph.D., Wilson M. Compton, M.D., and Susan R.B. Weiss, Ph.D.
    N Engl J Med 2014; 370:2219-2227June 5, 2014DOI: 10.1056/NEJMra1402309
    As marijuana use becomes legal in some states, the dominant public opinion is that marijuana is a harmless source of mood alteration. Although the harms associated with marijuana use have not been well studied, enough information is available to cause concern.

  4. My response to the New York Times editorial from Sunday July 27, 2014

    “Repeal Prohibition, Again”


    I am afraid I have to go against the grain… or in this case, the seed.

    I am not a journalist, nor does my livelihood depend upon people paying to read what I have written. I do not have to be sensational, controversial, or populist in my discourse (

    I am a physician – a specialist in pain management and addiction. I care deeply for my patients.

    I am also a father.

    I have no axe to grind with marijuana. I do not blame the innocent plant for society’s ills. A plant cannot think or feel or act. But journalists can.

    Granted, marijuana policies should evolve and more research should be done. But The New York Times editorial board went way too far in calling for an end to the “prohibition” of marijuana.

    The highly subjective statement that the ban on marijuana has “inflicted a great harm on society” is hyperbole.

    And saying that marijuana is “far less dangerous than alcohol” is not only unsubstantiated, but is, in itself, a dangerous statement. I wonder how many underage drinkers will now turn to smoking the “far less dangerous” joint because of this editorial… or is the Times confident that making twenty-one the marijuana legal age will prevent our youth from partaking? (Age limits keep kids from smoking and drinking, right?).

    As a physician who has probably studied this far more than the Times editorial board, I am appalled by the Times stating: “…the evidence is overwhelming that addiction and dependence are relatively minor problems, especially compared with alcohol and tobacco.”

    This is simply not true; at least that’s what the American Society of Addiction Medicine says. (

    I have never commented on a New York Times editorial. But as a physician, father, and someone who deeply cares about the health and well being of others, I needed to respond.

    James Patrick Murphy, MD, MMM
    Certified, American Board of Addiction Medicine
    Certified, American Board of Pain Medicine
    Certified, American Board of Anesthesiology/Pain


    “Repeal Prohibition, Again”


    It took 13 years for the United States to come to its senses and end Prohibition, 13 years in which people kept drinking, otherwise law-abiding citizens became criminals and crime syndicates arose and flourished. It has been more than 40 years since Congress passed the current ban on marijuana, inflicting great harm on society just to prohibit a substance far less dangerous than alcohol.

    The federal government should repeal the ban on marijuana.

    We reached that conclusion after a great deal of discussion among the members of The Times’s Editorial Board, inspired by a rapidly growing movement among the states to reform marijuana laws.

    There are no perfect answers to people’s legitimate concerns about marijuana use. But neither are there such answers about tobacco or alcohol, and we believe that on every level — health effects, the impact on society and law-and-order issues — the balance falls squarely on the side of national legalization. That will put decisions on whether to allow recreational or medicinal production and use where it belongs — at the state level.

    We considered whether it would be best for Washington to hold back while the states continued experimenting with legalizing medicinal uses of marijuana, reducing penalties, or even simply legalizing all use. Nearly three-quarters of the states have done one of these.

    But that would leave their citizens vulnerable to the whims of whoever happens to be in the White House and chooses to enforce or not enforce the federal law.
    The social costs of the marijuana laws are vast. There were 658,000 arrests for marijuana possession in 2012, according to F.B.I. figures, compared with 256,000 for cocaine, heroin and their derivatives. Even worse, the result is racist, falling disproportionately on young black men, ruining their lives and creating new generations of career criminals.

    There is honest debate among scientists about the health effects of marijuana, but we believe that the evidence is overwhelming that addiction and dependence are relatively minor problems, especially compared with alcohol and tobacco. Moderate use of marijuana does not appear to pose a risk for otherwise healthy adults. Claims that marijuana is a gateway to more dangerous drugs are as fanciful as the “Reefer Madness” images of murder, rape and suicide.

    There are legitimate concerns about marijuana on the development of adolescent brains. For that reason, we advocate the prohibition of sales to people under 21.
    Creating systems for regulating manufacture, sale and marketing will be complex. But those problems are solvable, and would have long been dealt with had we as a nation not clung to the decision to make marijuana production and use a federal crime.

    In coming days, we will publish articles by members of the Editorial Board and supplementary material that will examine these questions. We invite readers to offer their ideas, and we will report back on their responses, pro and con.
    We recognize that this Congress is as unlikely to take action on marijuana as it has been on other big issues. But it is long past time to repeal this version of Prohibition.

  5. It is definitely interesting to see a physician’s perspective on this topic, and I can definitely agree with your concerns that the medical concerns associated with marijuana may have been understated in the article. However, I disagree with you on one important point–restrictions and marijuana, and the laws associated with marijuana, have caused huge harm to society. This is further outlined in the explanation the Times issued and in the further pieces in the series, such as the following: The criminalization of marijuana has contributed hugely to America having the largest prison population in the world and the highest imprisonment rate of the developed world, largely for non-violent offenses. This is a serious problem, one that requires extreme reform.

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