Early Cannabis Use and BDNF Gene Variant Increase Psychosis Risk

May 3, 2017 · Posted in Genetics, Risk Factors · Comment 

Teen smoking marijuanaNormal variations in genes can affect risk of mental illness. One gene that has been implicated in psychosis risk is known as BDNF. It controls production of brain-derived neurotrophic factor, a protein that protects neurons and is important for learning and memory. Another important gene is COMT, which controls production of the enzyme catechol-O-methyltransferase, which breaks down neurotransmitters such as dopamine in the brain.

Several forms of these genes appear in the population. These normal variations in genes are known as polymorphisms. Certain polymorphisms have been linked to disease risk. A study by Anna Mané and colleagues published in the Journal of Psychiatric Research in 2017 explored links between COMT and BDNF polymorphisms, cannabis use, and age at first episode of psychosis.

Mané and colleagues found that among 260 Caucasians being treated for a first episode of psychosis, the presence of a BDNF polymorphism known as val-66-met and a history of early cannabis use were associated with younger age at psychosis onset.

The val-66-met version of BDNF occurs in 25-35% of the population. It functions less efficiently than a version called val-66-val.

The researchers also found that males were more likely to have used cannabis at a young age.

Editor’s Note: In the general population, marijuana use doubles the risk of developing psychosis. Previous data had indicated that the risk was higher for those with a COMT polymorphism known as val-158-val that leads to more efficient metabolism of dopamine in the prefrontal cortex. The resulting deficits in dopamine increase vulnerability to psychosis compared to people with the val-158-met version of the COMT gene.

The new study by Mané and colleagues suggests that a common form of BDNF may be associated with an earlier onset of psychosis. Bottom line: Pot is dangerous for young users and can induce psychosis, particularly in people at genetic risk. Pot may be legal in many places, but heavy use in young people remains risky for mental health and cognitive functioning.

The company Genomind offers genetic testing for BDNF and COMT variants as part of a routine panel.

Cannabis Use May Cause Schizophrenia

May 1, 2017 · Posted in Risk Factors · Comment 

marijuanaCannabis use has been linked to schizophrenia risk, and new genetic research suggests a causal relationship between the two. In a 2017 article in the journal Molecular Psychiatry, researcher Julian Vaucher and colleagues reported that lifetime cannabis use was linked to schizophrenia even when the researchers controlled for 10 genotypes weakly associated with lifetime cannabis use. This makes it unlikely that the schizophrenia caused the cannabis use, suggesting instead that it is the cannabis use that leads to a schizophrenia diagnosis.

Vaucher and colleageus also controlled for genetic associations between cigarette smoking and cannabis use to eliminate cigarette use as a third variable causing the association between cannabis and schizophrenia.

The study by Vaucher and colleagues included 34,241 people with schizophrenia and 45,604 healthy controls.

Smoking Pot While Pregnant is a No-No

Mom, Don’t Think Smoking Pot When Pregnant is Harmless for your Child

In a new article in Science, Jasmine Hurd reports on a large sample of mothers who smoked pot while pregnant. Their offspring were more anxious, hyperactive, and aggressive and had higher levels of the stress hormone cortisol in their hair at ages 3-6.

When Superstorm Sandy hit, mothers who were stressed and smoked pot while pregnant had children 31 times more like to have oppositional defiant disorder and 7 times more likely to have an anxiety disorder. Stress may interact negatively with the effects of pot.

In fetuses aborted after being exposed to pot while in utero had decreased dopamine receptors in the their amygdala and n. accumbens, a reward center in brain. In animal studies, pregnant mother rodents who were exposed to THC had offspring more likely to use heroin.


DADS’ BEHAVIOR COUNTS TOO. Dad’s exposure to THC as an adult also led to offspring who preferred opiates. This was based on epigenetic changes passed on in the sperm. To the extent that this also happens in humans, one could ask how much of the current opiate epidemic is based on parental use of marijuana. Mom’s and dad’s smoking pot could make their offspring more vulnerable to opiate addiction.

Cannabidiol Reduces the Anxiety Induced by Simulated Public Speaking in Treatment-Naïve Social Phobia Patients

M M Bergamaschi, et al reported in Neuropsychopharmacology volume 36, pages 1219–1226 (2011) that the one of the ingredient in cannabis, the diol or cannabidiol (CBD), containing none of the usual THC which make up the vast majority of plant-based marijuana, reduces the anxiety Induced by simulated public speaking in treatment-naïve social phobia patients.  They used “CBD (600?mg) in powder, ?99.9% pure (kindly supplied by STI-Pharm, Brentwood, UK and THC-Pharm, Frankfurt, Germany),… dissolved in corn oil.”  This CBD has shown efficacy in other anxiety disorders and is FDA approved for one form of seizure disorder.  This pure form of CBD is very expensive and usual preparations of available cannabis contain mostly THC and only minute amounts of CBD.  Thus, the generalizability of these results to people using the widely available preparations of cannabis is extremely unlikely. 

Environment Can Leave “Molecular Scars” Via Epigenetic Processes

May 29, 2020 · Posted in Genetics, Peer-Reviewed Published Data · Comment 
DNA

A 2020 review article by researchers Julia Richetto and Urs Meyer in the journal Biological Psychiatry provides a good overview of the role epigenetic modifications play in schizophrenia and related disorders.

The article provides a powerful understanding of how the environment can induce long-lasting changes in the structure of DNA (not only in schizophrenia, but also in bipolar disorder). This process, known as epigenetics, can have life-long influences on brain chemistry and behavior, and remarkably, some of these epigenetic changes can even be transmitted to the next generation.

While the sequence of DNA that one inherits from one’s parents does not change over the course of one’s life, what can change is how loosely or tightly the DNA is wound around proteins called histones, making it easier or harder to transcribe the genetic material held there. The addition of a methyl group to DNA usually inhibits transcription, while the addition of an acetyl group to histones usually facilitates transcription. These alterations in the shape of the DNA that result from environmental exposures or behavior can be passed on through generations.

Richetto and Meyer describe these chemical changes to DNA as “molecular scars,” which are left when environmental stress occurs during sensitive developmental periods. For example, patients with schizophrenia who experienced stressors in early life have higher levels of the enzyme histone deacetylase than patients who had stress or trauma later in life. Histone deacetylase would remove the acetyl groups on histones, which would inhibit gene transcription.

Other factors that have been implicated in epigenetic modifications in schizophrenia, such as DNA methylation of key developmental pathways, include pre- or post-natal stress, a challenge to a mother’s immune system during pregnancy, pre- and post-natal nutrition, exposure to drugs or toxic substances, and cannabis use in adolescence.

Richetto and Meyer suggest that epigenetics may explain why schizophrenia (and we would add bipolar disorder) can differ so much across individuals, and may help researchers and clinicians determine how best to treat different individuals.

Editor’s Note: This editor has written about how epigenetic changes can mediate sensitization to the recurrence of life stressors, episodes of mood disorder, and bouts of substance abuse, each of which can drive illness exacerbation and progression in bipolar disorder (see the 2016 article by Robert M. Post in the journal Bipolar Disorders, “Epigenetic basis of sensitization to stress, affective episodes, and stimulants: implications for illness progression and prevention”).

The chemical changes to our DNA, histones, and microRNA emphasize how important it is to begin long-term preventative treatment starting after a first episode of mania. This not only helps limit episode recurrence and the accumulation of stressors and bouts of substance use that can cause illness deterioration, but also limit the placement of these “molecular scars” on our DNA. The key to treating bipolar disorder is: prevent episodes, protect the person and the brain.

Endocannabinoid System May Help Explain Tourette Syndrome

May 19, 2020 · Posted in Neurochemistry, Peer-Reviewed Published Data · Comment 
Photo by Roman Bilik on Unsplash

Endocannabinoids are neurotransmitters produced by the human body that attach to cannabinoid receptors in the brain, the same receptors that are affected by the consumption of cannabis products.

Tourette syndrome, a neurodevelopmental disorder characterized by tics and psychological symptoms, is probably caused by some dysfunction involving the neurotransmitter dopamine. The syndrome is usually treated with dopamine receptor blockers but is also eased by cannabis use and treatment with THC, the main psychoactive component in cannabis. Recently, researchers set out to determine whether concentrations of endocannabinoids in the cerebrospinal system are related to Tourette syndrome.

In an article published in the journal Neuropsychopharmacology in 2020, researcher Kirsten R. Müller-Vahl and colleagues report that endocannabinoid concentrations were significantly higher in the cerebrospinal fluid of 20 people with Tourette’s syndrome than in 19 control participants without Tourette’s.

The researchers found elevations in the endocannabinoids AEA and 2-AG, the endocannabinoid-like ligand PEA, and the metabolite AA in the participants with Tourette’s syndrome. Levels of 2-AG in the cerebrospinal fluid correlated with severity of attention-deficit hyperactivity disorder symptoms, an aspect of the syndrome.

It is possible that higher concentrations of endocannabinoids are present in the syndrome because they compensate for the overactive influence of dopamine. This explanation would fit with the effectiveness of cannabis in treating Tourette’s. However, that has not yet been determined, and it is also possible that the endocannabinoids are a reaction to dysfunction involving other neurotransmitters, are incidental to the syndrome, or in the best case that they are a direct cause of the syndrome.

Müller-Vahl and colleagues suggest that based on the effectiveness of cannabis in treating Tourette’s, it may turn out that the syndrome is a sort of endocannabinoid deficiency. They believe this hypothesis is not counteracted by the high levels of cannabinoids they found in Tourette’s patients in this study, because these high levels may be accompanied by a reduced number or reduced sensitivity of the cannabinoid receptors or overactivity in the enzymes that break down endocannabinoids, such that it is difficult to maintain normal levels of these neurotransmitters.

In Animal Model, Long-Term THC Exposure Interferes with Cortical Control of the Nucleus Accumbens

April 21, 2020 · Posted in Peer-Reviewed Published Data, Risk Factors · Comment 
Cannabis plant. Photo by Esteban Lopez on Unsplash

In an article in the journal Biological Psychiatry, researchers Eun-Kyung Hwang and Carl R. Lupica reported that in rats, long-term use of THC (tetrahydrocannabinol) weakens input from the cortex to the reward area of the brain, the nucleus accumbens (NAc). Long-term THC use also strengthens connections to the NAc from emotional control (limbic) regions, such as the basolateral amygdala and ventral hippocampus. Hwang and Lupica reason that this shift from cortical control of the NAc to limbic control likely contributes to the cognitive and psychiatric symptoms associated with cannabis use.

Editor’s Note: Street marijuana largely contains THC rather than CBD, the beneficial, anxiety-reducing component of cannabis. Cannabis products are being decriminalized, but it is important to remember that those with THC are linked to cannabis use disorder and increased susceptibility to psychiatric illness. Patients with bipolar disorder who use marijuana also have a more adverse course of illness than those who do not use it.

One Hit of THC Tied to Psychotic Symptoms in Adults with No History of Mental Illness

April 17, 2020 · Posted in Peer-Reviewed Published Data, Risk Factors · Comment 
A woman rolls a joint. Photo by Thought Catalog on Unsplash

In a meta-analysis published in the journal Lancet Psychiatry, researcher Guy Hindley and colleagues reported that in otherwise healthy adults, a single dose of THC (equivalent to smoking one joint) produced transient psychotic symptoms.

The meta-analysis included 9 studies with a total of 196 participants. The researchers included studies in which participants took tetrahydrocannabinol (THC, the psychoactive component in marijuana) or placebo, and psychotic symptoms were measured.

The researchers also sought out studies in which cannabidiol or CBD was given in combination with THC, but there were not enough of these to derive significant results. CBD does not produce schizophrenia-like symptoms on its own, and some think it may have anti-psychotic effects, but findings on this topic have been mixed.

Taking THC had a large effect size on total psychotic symptoms and negative symptom severity (such as emotional flatness or avolition). It also had an effect on positive symptom severity (for example, hallucinations or delusions). The effects were larger with intravenous administration than with inhaled administration, and tobacco smokers had less severe positive symptoms.

Of four studies that included CBD, only one found that CBD reduced THC-induced psychotic symptoms.

Editor’s Note: Longer-term use of marijuana in adolescents and young adults doubles the risk of psychosis, and other data suggest that chronic use of marijuana at high doses can be associated with new onset of a diagnosis of bipolar disorder or schizophrenia. As cannabis products are being decriminalized around the US, it is worth noting some of the risks of marijuana use, particularly marijuana with a high level of THC.

Cannabidiol Drug Approved For Rare and Severe Types of Epilepsy

October 29, 2018 · Posted in Current Treatments · Comment 

epidiolex

In June, the US Food and Drug Administration (FDA) for the first time approved a drug derived completely from the cannabis plant. The drug, Epidiolex, a syrup, contains cannabidiol, the cannabis component that has been found to treat certain ailments. In a news release, the FDA stated that cannabidiol does not cause intoxication or a ‘high’. Tetrahydrocannabinol, or THC, is the cannabis component that makes people high, impairs cognition, and can induce paranoia.

The approval led, in September, to the Drug Enforcement Agency re-classifying FDA-approved drugs containing cannabidiol derived from cannabis and less than 0.1% THC as schedule V controlled substances. So far only Epidiolex meets these criteria. Cannabis had previously been classified as a schedule I controlled substance, in the same legal category as heroin, LSD, or ecstasy.

Epidiolex is now approved to treat two rare, severe types of epilepsy, Lennox-Gastaut syndrome and Dravet syndrome, in patients aged two years and older. It is the first FDA-approved treatment for Dravet syndrome, a genetic condition that appears in the first year of life when babies develop fever-related seizures. Other types of seizures, even including a continuous seizure state, can occur later.

Lennox-Gastaut syndrome also develops in young children, usually between the ages of three and five. They have multiple types of seizures with debilitating consequences.
In three randomized, double-blind, placebo-controlled clinical trials that included a total of 516 patients with either Lennox-Gastaut syndrome or Dravet syndrome, the drug reduced the frequency of patients’ seizures compared to placebo.

Side effects of Epidiolex include sleepiness, sedation and lethargy; elevated liver enzymes; decreased appetite; diarrhea; rash; fatigue, malaise and weakness; insomnia, sleep disorder and poor quality sleep; and infections. The FDA also warned in its approval that “[a]s is true for all drugs that treat epilepsy, the most serious risks include thoughts about suicide, attempts to commit suicide, feelings of agitation, new or worsening depression, aggression and panic attacks.” The drug is produced by GW Pharmaceuticals, which has already gained approval outside the US for a cannabis-based drug to treat multiple sclerosis.

Editor’s Note: It is important for readers to know that most marijuana available in the US contains mostly THC with minimal cannabidiol.

Cannabinoid Gel Treats Fragile X Syndrome

April 23, 2018 · Posted in Potential Treatments · Comment 

cannabidiol gel

Zynerba’s website depicts the gel

Fragile X syndrome is a genetic disorder characterized by developmental problems such as intellectual disabilities, cognitive impairment, and behavioral and learning challenges. Zynerba Pharmaceuticals announced in 2017 that a cannabinoid gel they have produced improved symptoms of fragile x syndrome in children and adolescents when applied daily to the upper arm.

Multiple cannabinoids are derived from cannabis plants, and include cannabidiol, which likely conveys some of the plant’s positive effects, and tetrahydrocannabinol (THC), which lends marijuana its psychoactive or psychomimetic effects, such as delusion or delirium. Cannabidiol is the active ingredient in the gel, and no THC was found in participants’ blood tests after using the gel.

The open study of 20 patients aged 6 to 17 years found that the participants showed improvement on a scale measuring anxiety, depression, and mood after 12 weeks of using the gel. The gel also appeared to improve aberrant behaviors including social avoidance, temper tantrums, repetitive movements, and hyperactivity. Treatment began at a dose of 50mg per day, and could be increased up to 250 mg per day within the first six weeks of the study. The dose then remained stable for the next six weeks.

Zynerba Pharmaceuticals hope to begin controlled clinical trials in 2018, with the goal of attaining approval for the drug from the US Food and Drug Administration. Other companies are also competing to garner the first FDA approval of a cannabis-based drug. Many of the drugs currently in development are intended to target neurological or behavioral conditions.

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