Underside of normal brain. Shown area has blood flow.
It’s a myth that marijuana is safe. While it has clear, proven benefits for certain physical ailments, the drug’s effect on those with psychiatric vulnerabilities, especially adolescents, can lead to psychosis and debilitating long-term cognitive impairment. Marijuana should not be political or partisan, yet it is. The research is international, which tends to refute the argument that concerns are political instead of medical. Advocates use the term “safe herbal medicine,” but avoid mention of its horribly unsafe effects. Like any psychoactive drug, there is serious risk of harm.
16-year old with 2 years regular marijuana use.
I was at a fundraising event once, chatting with a biochemist about brain chemistry. At one point he turned and asked a friend passing by about his party the night before, and the friend said that everyone was so stoned they could hardly stand up. This man then said he was sorry he missed it. I asked the scientist if he was aware of the negative effect marijuana had on the neurotransmitter serotonin, and how it causes psychosis. “You’re joking!” he said sarcastically. “What are you, some uptight ultra right reactionary?” A person nearby overheard us and chuckled and said to me, “Where have YOU been?” I’m just a parent who cares about kids, who is not buying the story out there. And I’ve read the peer-reviewed research on marijuana going back 20 years.
18-year-old with 3 year history of marijuana use, 4 times per week
I share this story because I assumed that an expert in the biological chemistry would know we don’t fully understand the astonishing complexities of brain chemistry, nor the compounding effect of genetics on a person’s reaction to substances. Why didn’t this man question his belief that marijuana is perfectly safe?
At the end of this article are summaries of research studies that have been conducted worldwide since 2004. All found negative effects of marijuana use on teens.
“When THC (tetrahydrocannabinol) was administered in one trial, it caused both patients and controls to experience transient increases in cognitive impairments and schizophrenia-like… symptoms.”
There are side effects. We know some people cannot stop using alcohol once they start, and that serious addiction runs in families. We now know that pharmaceuticals help some people, but have deadly side effects in others. Why isn’t marijuana, with proven negative side effects, also considered a risky substance like antipsychotics or arthritis medications or statins? Because it’s a plant, and not made by a giant corporation? Because it’s popular?
I work with adolescents in the juvenile justice system. A young man on my caseload grew noticeably depressed after starting regular marijuana use—this was tracked by weekly urinalysis. He said that smoking helped him feel better. I asked if he got depressed afterwards, and he shrugged. I asked if he thought it was safe, and he said, “Sure, because it’s natural. Everyone knows that.”
Pay attention, this is what teens think: marijuana is natural and therefore safe. That’s what sellers tell them and that’s what they tell each other. Advocates use the comforting term “safe natural herb.” Did you know that commonly used herbs are NOT safe?
- Comfrey is used in tea for arthritis pain, but causes liver damage.
- Arnica is used for pain, but causes kidney damage.
- Cinnamon bark is smoked by teens, and it causes disorientation, unconsciousness, and kidney damage.
- Ephedra (ma huang) causes heart attacks.
Research into smoked or consumed marijuana is repeatedly linked to the onset of psychotic symptoms such as hallucinations, cognitive impairments, and schizophrenic-like symptoms, regardless of a person’s age, even if they don’t use other narcotic substances. The risk is especially high for adolescents because they start using marijuana early.
A note on medical marijuana – The plant Cannabis sativa has two substances of interest:
- cannabidiol (CBD) – the molecule considered safe for a variety of treatments, and even approved by the upstanding American Medical Association;
- tetrahydrocannabinol (THC) – the molecule responsible for the high and the one that can produce psychotic symptoms.
Safe medical marijuana should not be the smoked leaf and buds, but as a dosed aerosol, and available by prescription, just as all other medications with possible negative side-effects. Legalizing only this form makes sense. Otherwise, legalization is not about medical need but recreational use.
“Increasing levels of cannabis use at ages 14-21 resulted in lower levels of degree attainment by age 25, lower income at age 25, higher levels of welfare dependence, higher unemployment, lower levels of relationship satisfaction, and lower levels of life satisfaction.” (read more below)
More than half the young people on my caseload have diagnosable disorders, or a history of addictions and disorders in their families. They’re already in trouble with the law. The last thing they need is the means to self-induce psychosis.
Share this information with other parents. This isn’t about keeping medicine away from people who need it, nor is it a “righteous” ploy to pick on people who like to get high. The danger for children is real.
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Early Marijuana Use Heightens Psychosis Risk in Young Adults (summary)
John McGrath MD, Rosa Alati MD Archives of General Psychiatry, published online March 1, 2010,
MedscapeCME: Psychiatry and Mental Health
“Early cannabis use increases the risk of psychosis in young adults,” reports lead investigator John McGrath, MD, of Queensland Centre for Mental Health Research in Brisbane, Australia. “Apart from having an increased risk of having a disorder like schizophrenia, the longer the young adults reported since their first cannabis use, the more likely they were to report isolated symptoms of psychosis.”
Investigators assessed 3801 study participants at ages 18-23 years, identifying first marijuana use and three psychosis-related outcomes: non-affective disease, hallucinations, and the Peters et al Delusions Inventory Score. “Psychotic disorders are common and typically affect 1 or 2 people of every 100” Dr. McGrath said, “…(I) was surprised that the results were so strong and so consistent… We need to think about prevention.”
Results mirror those of another study conducted by Michael Compton MD, published in the American Journal of Psychiatry (November 2009), where investigators looked at 109 patients in a psychiatric unit and found that daily marijuana and tobacco use was common. Of those who abused cannabis, almost 88% were classified as weekly or daily users before the onset of psychosis.
Emma Barkus, PhD, from the University of Wollongong in New South Wales, Australia, says other studies suggest that those who are engaging in risk behaviors about the age of 14 years are more likely to persist as they get older, adding further support to the role of cannabis use in predicting earlier psychoses.
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Evidence Accumulates for Links Between Marijuana and Psychosis (summary)
Michael T. Compton, MD, MPH – Assistant Professor, Emory University School of Medicine, Department of Psychiatry and Behavioral Sciences, Atlanta, Georgia, 2008
Cannabis is the most abused illicit substance in the general US population, and the most abused illegal drug among individuals with schizophrenia.This literature reviewed studies that examined (1) associations between cannabis use and clinical manifestations of psychosis, and (2) the biologic plausibility of the observed links.
The initiation of cannabis use among those with psychotic disorders often precedes the onset of psychosis by several years.Cannabis use in adolescence is increasingly recognized as an independent risk factor for psychosis and schizophrenia. Progression to daily cannabis use was associated with age at onset.
Study evidence also supported biological links between cannabis use and psychosis. In the brains of heavy users, interactions with specific cannabinoid receptors are distributed in brain regions implicated in schizophrenia. Other studies report elevated levels of endogenous cannabinoids in the blood and cerebrospinal fluid of patients with schizophrenia. When THC (tetrahydrocannabinol) was administered in one trial, it caused both patients and controls to experience transient increases in cognitive impairments and schizophrenia-like positive and negative symptoms. – - – - -
Chronic toxicology of cannabis. (summary)
Reece, Albert Stuart; Clinical Toxicology (Philadelphia, PA.) vol. 47 issue 6, Jul 2009 . Medical School, University of Queensland, Highgate Hill, Brisbane, QLD, Australia.
Findings: There is evidence of psychiatric, respiratory, cardiovascular, and bone toxicity associated with chronic cannabis use. Cannabis is implicated:
- In major long-term psychiatric conditions including depression, anxiety, psychosis, bipolar disorder;
- Respiratory conditions include reduced lung density, lung cysts, and chronic bronchitis;
- elevated rates of myocardial infarction and cardiac arrythmias;
- linked to cancers at eight sites, including children after in utero maternal exposure.- – - – -
Marijuana Use, Withdrawal, and Craving in Adolescents (summary)
Kevin M. Gray, MD, Assistant Professor in the youth division of the Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina in Charleston.
Findings in the literature survey: Initiation of marijuana use typically occurs during adolescence. Recent data indicate that in the United States, 42% of high school seniors have tried marijuana; 18% have used it in the past 30 days; and 5% use it daily. Among adolescents aged 12 to 17, 3.6% met criteria for cannabis use disorder (abuse or dependence) and 2% met criteria for cannabis dependence.
More than half (51%) of adolescents reported that marijuana is fairly or very easy to obtain. Ironically, this ready availability may be a “reverse gateway” from marijuana use to cigarette use to nicotine dependence. Earlier initiation is associated with problem-related marijuana use: “hard” drug use, poly-drug use, and academic failure. Using marijuana once per week or more during adolescence is associated with a 7-fold increase in the rate of daily marijuana use in young adulthood. Cannabis dependence increases the risk factors for impaired driving and delinquent behavior. Chronic use is associated with impaired immune function, respiratory illnesses, cognitive problems, and motivational impairment.
There is a debate whether marijuana use begins as “self-medication” for psychiatric disorders, or whether habitual marijuana use can predispose some individuals to psychiatric symptoms.
Social anxiety disorder in adolescence is associated with 6.5-times greater odds of subsequent cannabis dependence, and vice versa, frequent marijuana use during adolescence appears to increase the risk of subsequent development of anxiety and depressive disorders. The prevalence of cannabis abuse is 2 to 3 times greater among adolescents who have major depression. Also linked in both directions: conduct disorder predicts marijuana and other substance use, while early-onset marijuana use predicts conduct disorder.
Five treatment regimes were studied: motivational enhancement/cognitive-behavioral therapy (MET/CBT), family education and therapy intervention, a community reinforcement approach, and multidimensional family therapy. All resulted in positive but modest outcomes, with MET/CBT and community reinforcement treatments being most cost-effective.
Emerging evidence indicates rewards for marijuana abstinence may be positive. Multi-systemic therapy, an intensive approach that incorporates individual, family, and community components, has demonstrated effectiveness among delinquent adolescents.
Withdrawal: Marijuana withdrawal symptoms are a constellation of emotional, behavioral, and physical symptoms that include anger and aggression, anxiety, decreased appetite and weight loss, irritability, restlessness, and sleep difficulty, which result specifically from withdrawal of marijuana’s psychoactive ingredient, THC. Less frequent but sometimes present symptoms are depressed mood, stomach pain and physical discomfort, shakiness, and sweating. Onset of withdrawal symptoms typically occurs within 24 hours of cessation of THC, and symptoms may last days to approximately 1 to 2 weeks.
Craving: Patients’ craving of marijuana is evidenced after presenting them with cues associated with marijuana (e.g. sight or smell of the substance, films of drug-taking locations, and drug-related paraphernalia). Exposure to cues leads to robust increases in craving, along with modest increases in perspiration and heart rate. Cue reactivity can predict drug relapse.
Craving and withdrawal symptoms interfere with successful cessation of use and sustained abstinence. In addition, medications are often used to target withdrawal from substances, such as benzodiazepines for alcohol dependence and clonidine and buprenorphine for opioid dependence. These medications could be combined with psychosocial interventions, or developed to complement concurrent psychosocial treatments. – - – - -
Legalization of Marijuana: Potential Impact on Youth (summary)
Alain Joffe, MD, MPH, W. Samuel Yancy, MD the Committee on Substance Abuse and Committee on Adolescence – PEDIATRICS Vol. 113 No. 6 June 2004, pp. e632-e638
Scientists have demonstrated that the emotional stress causedby withdrawal from marijuana is linked to the same brain chemical that has been linked to anxietyand stress during opiate, alcohol, and cocaine withdrawal. THC stimulates the same neurochemical process that reinforcesdependence on other addictive drugs. Current, well known, scientific informationabout marijuana shows the cognitive, behavioral,and somatic consequences of acute and long-term use, which include negative effects on short-term memory,concentration, attention span, motivation, and problem solving. These clearly interfere with learning, and have adverse effects on coordination,judgment, reaction time, and tracking ability. http://pediatrics.aappublications.org/cgi/content/full/113/6/e632 - – - – -
The Past, Present, and Future of Medical Marijuana in the United States (summary)
By John Thomas, JD, LLM, MPH, Professor of advanced law and medicine, civil procedure, and commercial law at the Quinnipiac University College of Law, Hamdon, Connecticut, January 6, 2010
Cannabidiol (CBD) is considered safe and has a variety of positive benefits, and this component should be legalized. However, the other narcotic component in marijuana, tetrahydrocannabinol (THC), is responsible for the high, and too much may not be a good thing because it can produce psychotic symptoms in people. – - – - -
Medical Marijuana: The Institute of Medicine Report (summary)
Ronald Pies, MD, Editor in Chief – Psychiatric Times. Vol. 27 No. 2 , January 6, 2010
Marijuana is not a completely benign substance. It is a powerful drug with a variety of effects. However, except for the harms associated with smoking, the adverse effects of marijuana use are within the range of effects tolerated for other prescription medications. Cannabinoids can induce acute transient psychotic symptoms or an acute psychosis in some individuals… (but it is unclear) what makes some individuals vulnerable to cannabinoid-related psychosis. There is a pressing need for more high-quality research in the area of medical marijuana and cannabinoid use. – - – - -
Link Between Cannabis Use and Psychosis Onset at a Younger Age (summary)
Ana Gonzales MD, Santiago Apostol Hospital in Vitoria, Spain, Journal of Clinical Psychiatry. August 2008
Researchers found a strong and independent link between cannabis use and the onset of psychosis at a younger age, regardless of gender or the use of other drugs. The link is related to the amount of cannabis used. “The clinical importance of this finding is potentially high,” Dr. Gonzalez-Pinto given that cannabis use is extremely prevalent among young people… estimates of the attributable risk suggest that the use of cannabis accounts for about 10 percent of cases of psychosis.”The findings showed a significant gradual reduction in the age at which psychosis began that correlated with an increased dependence on cannabis. Compared with nonusers, age at onset was reduced by 7, 8.5, and 12 years among users, abusers, and dependents, respectively, the researchers report. – - – -
Cannabis use and later life outcomes. (summary)
Fergusson DM, Boden JM, Addiction; Pages: 969-76; Volume(Issue): 103(6), June 2008
A longitudinal study of a New Zealand birth cohort tracked subjects to age 25 years. Cannabis use at from ages 14-25 was measured by: university degree attainment to age 25; income at age 25, welfare dependence during the period 21-25 years, unemployment 21-25 years, relationship quality, and life satisfaction. Other indices were measured to adjust for confounding factors: childhood socio-economic disadvantage, family adversity, childhood and early adolescent behavioral adjustment and cognitive ability, and adolescent and young adult mental health and substance use.The findings were statistically significant. Increasing levels of cannabis use at ages 14-21 resulted in lower levels of degree attainment by age 25, lower income at age 25, higher levels of welfare dependence, higher unemployment, lower levels of relationship satisfaction, and lower levels of life satisfaction. – - – - -
Doctors: Pot Triggers Psychotic Symptoms (summary)
May 1, 2007 Aetna Intelihealth – Mental Health
LONDON — New findings show physical evidence of the drug’s damaging influence on the human brain. In some people, it triggers temporary psychotic symptoms including hallucinations and paranoid delusions. Two of the active ingredients of cannabis: cannabidiol (CBD) made people more relaxed. But second ingredient: tetrahydrocannabinol (THC) in small doses produced temporary psychotic symptoms in people, including hallucinations and paranoid delusions. According to Dr. Philip McGuire, a professor of psychiatry at King’s College, London, THC interfered with activity in the inferior frontal cortex, a region of the brain associated with paranoia. “THC is switching off (a chemical) regulator,” McGuire said, “effectively unleashing the paranoia usually kept under control by the frontal cortex.”In another study, Dr. Deepak Cyril D’Souza, an associate professor at Yale University School of Medicine, and colleagues tested THC on 150 healthy volunteers and 13 people with stable schizophrenia. Nearly half of the healthy subjects experienced psychotic symptoms when given the drug. Unfortunately, the results for the schizophrenic subjects was so much worse that researchers scrapped adding additional schizophrenic subjects to the study. The negative impact was so pronounced that it would have been unethical to test it on more schizophrenic people.”One of the great puzzles is why people with schizophrenia keep taking the stuff when it makes the paranoia worse,” said Dr. Robin Murray, a professor of psychiatry at King’s College in UK. She theorized that schizophrenics may mistakenly judge the drug’s pleasurable effects as outweighing any negatives. – - – - -