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Increase Potency of Marijuana and its Impact on the Brain

Potency of Marijuana

The marijuana today is not the marijuana of the 60’s, 70’s or even 80’s. Today, we see marijuana bud at 26% THC and many users are now using high THC concentrates such as butane hash oil (BHO), ear wax, dabs, budder, shatter, and edibles near 70%-90% THC.

According to the University of Michigan’s Monitoring the Future Survey, which has been tracking the trends of teen drug use since 1975, the average age of first intoxication is 12 years old. Neuroscientist and director at NIDA (National Institute of Drug Abuse) Nora Volker, MD reports that the teen brain is not finished developing until the mid-20’s. Studies show that if a teen is abusing drugs they are to 7-10 times more likely to develop a mental health disorder later in life and 4 times more likely to develop an addiction to their drug of choice.

As a result of man-made hybridized marijuana plants, i.e., cloning, hydroponics and sophisticated THC extracting devices, we live in a world that has easy access to very potent THC. Sadly, as a result, we are seeing serious mental health issues. We know that while the teen brain is still developing the impact of marijuana use can disrupt the development of the dopamine, anandamide and even the serotonin systems.

In the last few years those of us working with teens and young adults with cannabis disorders have seen a trend in side effects now resulting in panic attacks, anxiety, and psychosis leading to hospitalizations for some users. According to Neuroscientist Dr. Christine Miller, there is also a link to Schizophrenia. I am sure that most of the old pot users would have laughed at this back in the day.

The following has been taken from Dr. Miller’s presentation in Sacramento last year.


Hundreds of peer-reviewed, scientific articles show a correlation between marijuana use and psychotic outcomes such as schizophrenia, too numerous to list here. The question of whether marijuana is causal for psychosis has been answered in the affirmative by applying standard principles of causation used in pharmacological and epidemiological research. The increase in heavier dose use marijuana results in more users developing schizophrenia. Administration of the active ingredient (THC) in the clinic under controlled conditions causes psychotic symptoms

Self-medicating is not that likely, because many will try to quit to avoid the psychotic symptoms before they become too impaired but for others it may be too late. Marijuana use generally comes before the psychosis, not vice-versa

In users who have schizophrenia, the age of onset is earlier than for non-users. The average onset of schizophrenia in men is 18 and 25 for women. Of all recreational drugs, marijuana use is the most likely to result in chronic psychosis.

1. What percentage experience a psychotic outcome? The low to moderate-strength marijuana available in the last century was shown to trigger single psychotic symptoms (paranoia, racing thoughts, delusions, hallucinations) in 12% to 15% of users. Of those with such “prodromal” symptoms (denoting the period between the appearance of initial psychotic symptoms and the full development psychotic symptoms) about 35% can be expected to develop full psychosis, i.e. a constellation of symptoms occurring at once. For about half of these individuals, conversion to chronic schizophrenia spectrum disorder occurs irrespective of family history. The result for low to moderate-strength marijuana was about a 2.5-fold increased risk of schizophrenia, but for the high strength product available today, the risk for schizophrenia is 5-fold compared to non-users. That increase in risk translates into about one out of every twenty users if they don’t quit in time.

Is this impact limited to adolescence? Given that the brain continues to develop in males through the late twenties, it seems unlikely that the risk for chronic psychosis is limited to adolescent users. Furthermore, administration of THC to adults in a clinical setting results in psychotic symptoms.


Risks for anxiety, panic, and depression are increased by marijuana use: with some studies showing that correction for confounding variables lessens the association with anxiety and depression, while others report the effect remains.


Risk for suicidal ideation is increased on average 7-fold: even after correcting for a prior history of depression.

In 2014 the second year after legalization of recreational use of marijuana, Colorado experienced the highest suicide rate in state history. In 2014, there were 1,058 suicides among Colorado residents and the age-adjusted suicide rate was 19.4 per 100,000. This is the highest number of suicide deaths ever recorded in Colorado. These findings were included in The Office of Suicide Prevention in their Annual Report 2014-2015, Colorado Department of Public Health and Environment.

Particularly alarming, the Colorado media has reported sudden onset suicidal ideation or completed suicide in consumers of commercial edibles, but also reported following the smoking of potent marijuana. These responses can happen so quickly in individuals who were not previously suicidal that intervention may be impossible.

Lack of educational achievement and decreases in motivation has been contributed to an increase in the use of marijuana. The odds for marijuana users completing high school are reduced to about 0.37-fold that of controls accounting for demographics and other factors, marijuana use adversely affected college academic outcomes, both directly and indirectly through poorer class attendance Decreases in motivation with marijuana use have been documented in clinical studies of humans and animals.

Impact on IQ:

Studies have shown that up to an approximate 7 point drop in IQ from childhood scores by age 38 in marijuana users who have been abstinent for 24 hours prior to testing; but only an approximate 5 point drop in those abstinent for a week prior to testing. A subsequent study of twins yielded mixed results, with an average decline of 4 points in marijuana users by late adolescence; however, restricting the comparison to the matched twins (thereby controlling for genetics and a myriad of environmental factors), the effect of marijuana largely disappeared. The limitation of this later study is that brain development is not complete by late adolescence, particularly the wiring of the all-important cortex is still ongoing through the late twenties There is no controversy, however, about the negative, real-time impact of marijuana use during tests of cognition and memory.

Thom Kessler, LMFT, RAS