Thursday, March 31, 2011

Marijuana and the Risk of Schizophrenia

By Ken Duckworth, M.D., NAMI Medical Director

The ongoing link between use of marijuana in teens and the increased risk of developing schizophrenia has been further developed in a recent Dutch study published in the British Medical Journal (BMJ) and has re-ignited that area of interest. This study has important public health implications, because our capacity to prevent psychiatric illnesses is severely limited-although a recent small Omega-3 fatty acid study in the Archives of General Psychiatry suggests, in contrast, a protective impact.

The BMJ study looked at young adults who were at risk for psychosis and found that the rate of conversion to the illness was 51 percent with marijuana users-compared with 26 percent of nonusers. This study builds upon a growing body of literature that is making this causative link. This build upon other studies-one of the most interesting to me was a study that made a case for delaying all experimentation---the study found that users before age 15 were 4.5 times more likely to develop schizophrenia than nonsmokers, and those who delayed until age 18 had a risk of 1.6. This strongly suggests that, in addition to abstinence, delaying experimentation results in reduced risk.

Why do some people have no issues with this choice while another subset will never be the same after use? We do not know for sure, but interest has been growing on looking at generic variability. A gene variation in the metabolism of the neurochemicals dopamine may confer much of the risk. Unfortunately, there is not a test to determine if a group of teens will become symptomatic if they experiment. So all teens have an unknown but variable risk-a difficult area to impart wisdom in. It is very hard to be sure what the risk for use of marijuana is for any one teen, but use is clearly risky when you look at a population as a whole. This risk is even worse for kids with a family history of psychosis.

As a father of three teen girls (who also has a history of bipolar disorder with psychosis in my genes), I do my best to share with my kids that, in my view, all drug experiments need to be delayed-or denied. Teens are notorious for not listening to parents and for not delaying gratification, so I can't know what is actually getting through. I suspect it is less than I would like. Developing good decision-making skills is one of the key aspects of growing up, but there is no one way to get there. Learning by experimentation is one way, but as these studies show, the consequences can be much greater than anticipated.

Knowing your family risk (e.g. of schizophrenia or alcoholism or diabetes) is a good perspective to share with your kids so that they know that drugs, alcohol and sugar are even more worrisome for them. What they do with that kind of information is beyond parental control. Like teaching teens to drive a car, you hope to model and impart experience, and then you wait as they learn. I encourage my kids and the people who live with mental illness whom I treat as a doctor to wear seat belts and to avoid drugs. Then like all parents, I hope for the best and do my best to coach as more data comes in on their choices. But there are no guarantees. In neurobiology--just like with driving vehicles--all we can do is work to lower the chance of complications.

14 comments:

*rachel* said...

Thank you. My son was diagnosed with sz last year. An uncle on his fathers side has it severe and I hadn't realized the risk until my son began to Have symptoms. My son to This day has a hard time accepting his diagnosis and thinks if he hadn't started smoking pot the year before, he wouldn't Have sz now. Of course, one will never know, but I am paying attention to articles Like yours in my desire to KNOW everything about my sons illness. Thank you.

Cole said...

Very interesting Dr. Duckworth. I recreationally used marijuana in h.s. and college--only one ever few months if even that. Last May I had a really bad trip that led me to the psychologists office because of overwhelming paranoid and anxious thoughts. After almost one year I am finally no longer visiting but I will have to deal with the experience the rest of my life.

Politics aside, we need to get this kind of information out in the open to the public so that individuals can make the best personal decision for themselves.

Cole said...

Very interesting Dr. Duckworth. I recreationally used marijuana in h.s. and college--only one ever few months if even that. Last May I had a really bad trip that led me to the psychologists office because of overwhelming paranoid and anxious thoughts. After almost one year I am finally no longer visiting but I will have to deal with the experience the rest of my life.

Politics aside, we need to get this kind of information out in the open to the public so that individuals can make the best personal decision for themselves.

Patjeff said...

If marijuana use increases the risk of schizophrenia, then why hasn't its prevalence increased since marijuana use became widespread in the late 1960s?

And why do countries with very low rates of marijuana use (e.g. Japan) have virtually identical rates of schizophrenia as countries with very high rates of marijuana use (e.g. the USA)?

Anonymous said...

I highly suspect that Marijuana played a role in my son developing Schizophrenia. He started using Marijuana around age 13 and became a heavy user around 15. He started developing pyschotic symptoms when he was 16. Unfortunately, he committed suicide prior to being officially diagnosed with any mental health disorder, but he was showing many of the signs of Schizophrenia such as hearing voices, delusions of grandior, et.)

Tupsy said...

My ex husband has recently been diagnosed with paranoid schizophrenia after many years of anxiety, fear, paranoia, hostility and nightmares. It is at least good to now understand why he behaved the way he did during our marriage. When he was 14 he and some mates got into smoking marijuana quite heavily for a short time. Then he joined the army at 18 and had no more interest in smoking dope or taking any other drugs (except tobacco). So the theory of the marijuana triggering schizophrenia absolutely fits in his case.
Thank you for this
Tupsy

Tupsy said...

Do you know of any evidence for marijuana triggering bi-polar disorder?

Anonymous said...

this is popostris they have been trying to find something wrong with marijuana since it has been introduced to the world populous.

man hair loss said...

wow, very informative... its nice to actually know what marijuana can do to users and not just say that they're high... i can still remember when i was in college and everything seem to be just a "trial basis" being high would be a great experience especially when you're depress, but other than that, i learned, it isn't all that worth it really...

Catherine said...

The report abstract states: Conclusion Cannabis use is a risk factor for the development of incident psychotic symptoms. Continued cannabis use might increase the risk for psychotic disorder by impacting on the persistence of symptoms.

This is not about schizophrenia.

Anonymous said...

I am convinced about the link between cannabis and bipolar/schizophrenia disorder. There is a case study in the Journal Psychiatry 2009 volume 6 number 12, December 1 " Cannabis induced Bipolar disorder with psychotic features: a case report". It is unfortunate that some young adults will develop the disorder after heavy use while others are not affected. My son is one of those who is paying the price of his use as an adolescent.

Anonymous said...

I recently did a reseach paper on this very topic. It is an interesting topic and raises some questions. Thought I feel that there truly is a link between smoking marijuana and schizophrenia we need to remember that there are other risk factors such as age, gender,gentics amoung other things. I also think that medical marijuana is fine but must ask are doctors taking a full medical history before giving to patients? Are doctors taking the schizophrenia risk factors into consideration when prescribing marijuana to patients? I think it is important to think about these things before someone uses the drug and if you have risk factors or due in fact have schizophrenia you should avoid using marijuana.

HexagonGroup said...

Omega 3 fatty acids and other Essential Fatty Acids are vital to protect against mental misfires. THC, the active ingredient in marijuana, is like "raking the board" to use a special effects explosives metaphor. Instead of the slow release of some rather exotic fats by the brain in the normal course of functioning, THC releases all those hard-to-replace exotic fat fractions all at once. Chaotic brain firing ensues, and the Hippocampus (memory) and Pre-Frontal Cortex (judgment) get scrambled messages. Studies have not shown Hippocampus atrophy from stress hormones/cortisol as affected by THC. But stress causes Hippocampus damage, literal brain damage. Throw pot in on top of that and otherwise healthy people, possible abuse victims as children, can get screwy. One of the best sources of the exotic EFA's stripped out by THC is...hemp oil. Yep. The very thing that compromises the brain when ingested can bolster brain function. One may also note the role of digestion. Those with low stomach acid, a tendency in Native American and Irish populations, or those having poor digestion, may not be able to pull out the Essential Fatty Acids from their food! So many mental aberrations can be caused by poor digestion, hence the title of my piece, "You're Nuts Because of Your Guts." Over 70% of mid-brain chemicals are made in the gut, and this may be the X factor in the pot psychosis mystery. Our modern diet is full of trash fats, and it is like giving a starving dog a rubber bone. Eat raw oils and a good well-marbled organic ribeye steak now and again. Enjoy a poached organic egg yolk, full of lecithin/choline, or take soy lecithin if you tolerate soy well. Take purified Omega 3 fish oils that have had the mercury removed or eat organic walnuts, chewing well. Supplement with lipase to digest fats and oils. Feed your fat head--the brain is made up of lipo-protein, fat-linked proteins. GBU! PS Modern pot is now a hybrid of Cannabis Sativa and Cannabis Indica, formerly called ditch weed. Ditch weed causes headaches and sinus infections when smoked, and gives that skunk smell. Users report less intense orgasm, btw, probably a result of the phyto-estrogen content. Oy.

Rusty Covey said...

I have to disagree with this finding, they would have gotten worse with time.
I have lived with this condition since the age of 10, I couldn't stop the images from appearing.
I started smoking marijuana at age thirteen and also learning how to read and write. My schizophrenia went away completely.
A guy named WG with severe paranoia-schizophrenia, when he smoked marijuana he was able to relax and get into the moment.
Another named CR, didn't experience schizophrenia when he was high. But, when he used crank it would bring out this condition.
Thus, were these test subjects free of stress. Stress seems to be a precursor to developing an episode of schizophrenia.
Marijuana should be reducing stress, so, makes me wonder how the test subject were before the testing, how long did they actually allow the test to be done with the same subject and was there any type of therapy.
By the way I teach The Nine Essential Qualities of Mindfulness along with The Five Sense Therapy.