I have had some students reach out to me interested in the side effects of marijuana usage.

This chart does a good job of putting together a lot of complex info in a really simple way...

It is hard to navigate the research out there even once you have parred it down to the legitimate unbiased research. Even when correlations are found, causation remains unclear.

Here are some of the main concerns though when it comes to the effects of marijuana usage. It's all so controversial.

1) One concern is the effects on IQ/brain functioning. The findings are unclear. The study I noted during lecture is noted in most psych textbooks and forms the foundation for the widely taught idea that marijuana lowers IQ. One of the main points of this research is that this is when marijuana usage is started in the teen years, again emphasizing "do not use drugs while the brain is still developing." While age 25 is often noted as the age by which the brain is fully developed, other research points to later 20s and even early 30s for some.

"Marijuana also affects brain development. When people begin using marijuana as teenagers, the drug may impair thinking, memory, and learning functions and affect how the brain builds connections between the areas necessary for these functions. Researchers are still studying how long marijuana's effects last and whether some changes may be permanent. For example, a study from New Zealand conducted in part by researchers at Duke University showed that people who started smoking marijuana heavily in their teens and had an ongoing marijuana use disorder lost an average of 8 IQ points between ages 13 and 38. The lost mental abilities didn't fully return in those who quit marijuana as adults. Those who started smoking marijuana as adults didn't show notable IQ declines (National Institute on Drug Abuse)." 8 points is enough to have a substantial effect on one's life. This is the study I noted during lecture.

Another recent study (a twin study) speaks to a possibility that maybe the IQ decline is caused by other factors, such as genetics and family environment. This is saying maybe marijuana usage is just correlated to drops in IQ and it does not cause the drops.

I can imagine them eventually coming to a consensus that marijuana causes drops in IQ only when certain other nature and nurture factors are in place, ex. presence of certain genes. This is just a guess of mine though.

Any confusion out there in the research yells that we just don't know everything about these things yet and we need to do more research!! When it comes down to it, we aren't sure what the long term effects are.

"Rats exposed to THC before birth, soon after birth, or during adolescence show notable problems with specific learning and memory tasks later in life. Cognitive impairments in adult rats exposed to THC during adolescence are associated with structural and functional changes in the hippocampus. Studies in rats also show that adolescent exposure to THC is associated with an altered reward system, increasing the likelihood that an animal will self-administer other drugs (e.g., heroin) when given an opportunity."

Memory issues- Do not study while high. It is clear marijuana impacts memory while you are high. "Another measure of executive function is working memory. For more than 40 years, researchers have shown that cannabis consumption impairs working memory, or the ability to hold and manipulate information and remember it following a short delay (Tinklenberg et al., 1970; Miller et al., 1977; Heishman et al., 1997). This finding has been replicated in present day research. In a recent study of chronic cannabis users, Hart et al. (2001) found that acute intoxication resulted in significant impairment in working memory, and those subjects receiving a higher dose of THC (3.9%) took significantly longer to complete the task." ( https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3037578/ )

2) Another concern:

Long-term marijuana use has been linked to mental illness in some people. "Clinicians agree that cannabis use can cause acute adverse mental effects that mimic psychiatric disorders, such as schizophrenia and bipolar disorder. Although there is good evidence to support this, the connections are complex and not fully understood (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2811144/)." I know a lot of people that won't smoke because they become paranoid (and miserable) when they are high.

Questions: Yes marijuana can produce short-term psychosis in anyone, but what about the long-term? Can it trigger schizophrenia in those with a genetic predisposition? In other words, can it increase the risk of schizophrenia for those with a genetic predisposition? "Recent research (see "AKT1 Gene Variations and Psychosis") has found that people who use marijuana and carry a specific variant of the AKT1 gene, which codes for an enzyme that affects dopamine signaling in the striatum, are at increased risk of developing psychosis. The striatum is an area of the brain that becomes activated and flooded with dopamine when certain stimuli are present. One study found that the risk of psychosis among those with this variant was seven times higher for those who used marijuana daily compared with those who used it infrequently or used none at all." "Another study found an increased risk of psychosis among adults who had used marijuana in adolescence and also carried a specific variant of the gene for catechol-O-methyltransferase (COMT), an enzyme that degrades neurotransmitters such as dopamine and norepinephrine." (https://www.drugabuse.gov/publications/research-reports/marijuana/there-link-between-marijuana-use-psychiatric-disorders)

Can it speed up onset--essentially causing someone to lose touch with reality sooner than they would have? Can it worsen symptoms for someone with schizophrenia/psychosis? The answer seems to be yes. "Marijuana use has also been shown to worsen the course of illness in patients who already have schizophrenia."

onset of schizo cannabis.PNG

(SKUNK HAS A LOT MORE THC THAN HASH. THIS BRINGS UP A REALLY IMPORTANT ISSUE-- THE THC LEVELS IN MARIJUANA KEEPS INCREASING... SO MAYBE THESE POSSIBLE LONG-TERM CONSEQUENCES ARE MORE SEVERE THAN PAST RESEARCH AS IMPLIED. )

(At the same time, I think again of correlation vs. causation issues. Maybe those that are going to "lose their minds" sooner are simply the individuals who also use more marijuana.")

Pretty good article: https://www.npr.org/sections/health-shots/2015/03/06/390143641/pot-can-trigger-psychotic-symptoms-for-some-but-do-the-effects-last

3) Another concern (I just mentioned this above):
"A Rise in Marijuana’s THC Levels
The amount of THC in marijuana has been increasing steadily over the past few decades. For a person who's new to marijuana use, this may mean exposure to higher THC levels with a greater chance of a harmful reaction. Higher THC levels may explain the rise in emergency room visits involving marijuana use.
The popularity of edibles also increases the chance of harmful reactions. Edibles take longer to digest and produce a high. Therefore, people may consume more to feel the effects faster, leading to dangerous results.
Higher THC levels may also mean a greater risk for addiction if people are regularly exposing themselves to high doses (National Institute on Drug Abuse)."

The increase in THC levels could increase all other risks/concerns/possibilities...

4) What are you actually getting out on the streets???

To sum up:

From the Director of The National Institute on Drug Abuse:

"Because marijuana impairs short-term memory and judgment and distorts perception, it can impair performance in school or at work and make it dangerous to drive. It also affects brain systems that are still maturing through young adulthood, so regular use by teens may have negative and long-lasting effects on their cognitive development, putting them at a competitive disadvantage and possibly interfering with their well-being in other ways. Also, contrary to popular belief, marijuana can be addictive, and its use during adolescence may make other forms of problem use or addiction more likely."

"Whether smoking or otherwise consuming marijuana has therapeutic benefits that outweigh its health risks is still an open question that science has not resolved."

There is so much to study out there when it comes to all of this, but it is clear that age of use, duration of use, and amount used matters when it comes to the effects of marijuana.

None of this considered the overall effect of marijuana use on life satisfaction and overall life functioning. That is a completely different animal, and even more complicated. I do want to be clear--people love to talk about the positives of marijuana, but it is not a magically safe, "makes everyone better" drug. There is a dark side to marijuana usage, some of you know this dark side personally, whether because of your own usage or that of loved ones. Addiction and abuse are absolutely possible. This is not to say there aren't people out there who have had wonderful experiences using marijuana--it's just to say that's definitely not always the case! (I have seen A LOT of depression and motivation issues related to usage.)

If marijuana ends up being considered a "safe drug," where are the limits? What is too much use? How many hits a week is too much? At what point does marijuana go from having a good or neutral impact to a bad impact on your life and social, emotional, and mental health? Is an individual able to recognize when they have crossed this threshold? If they can recognize it, can they cut back or stop usage? A lot of people use marijuana to self medicate. Are they in a situation where medication should be a temporary thing to help ease symptoms to deal with underlining problems? Are they using marijuana as that temporary help and working on things in other ways, like with Psychotherapy? How many get stuck in a cycle of perpetual self medication, without additional help, and can this eventually lead to the exacerbation of underlining issues?

I don't have the answers here. Sorry :). It took a LONNNGGG time even to find these unclear answers, haha. I wish the answers were simple and I did have them.

effects of cannabis.PNG

In all of this I do think about how cocaine was once considered a relatively harmless recreational drug. We just don't know.