THE PATHOPHYSIOLOGY OF SCHIZOPHRENIA IS BECOMING CLEARER
David Lewis of U. Pittsburgh showed that the glutamate neurons in the prefrontal cortex of patients with schizophrenia are deficient in the gamma (30-50 Hz) oscillations that are responsible for normal working memory.
Not only are dendrites and spines deficient in these neurons in layer 3 of the cortex, but there is a deficit in parvalbumin GABA inhibitory neurons. The GABA enzyme GAD 67 is lower, producing less inhibition. The frontal neurons are hypoactive and there is less BDNF and oxidative phosphorylation present, yielding decreases in mitochondrial function.
Cannabis and Cannabinoids Don’t Work for Pain or Posttraumatic Stress Disorder
Aaron S. Wolfgang, MD and Charles W. Hoge, MD reviewed data on cannabis in JAMA Psychiatry and found that there were big placebo effects and no evidence for effectiveness of cannabis in military personal.
This negative data, along will all the liability of cannabis potentially causing or triggering psychosis, bipolar disorder, and schizophrenia (as well as possibly contributing to cognitive dysfunction, worsening anxiety and depression in patients with mood disorders) makes the use of pot for medical purposes an entirely foolhardy proposition, as well as a waste of money.
Legalization of pot has helped people avoid jail but precipitated a rash of use and over use.
So the bottom line from this editor is: Get Your Priorities Straight. Cannabis and Cannabinoids Don’t Work for Pain or Posttraumatic Stress Disorder and they Worsen Most Everything Else. Save your Money and Do Something Nice for Yourself and Others Instead.
Cannabis Contributes to 15% of Case of Schizophrenia
A study in Psychological Medicine (May 2, 2023) reported on ” Danish registry data spanning five decades and representing more than 6.9 million people in Denmark to estimate the population-level percentage of schizophrenia cases attributable to (cannabis use disorder) CUD. A total of 60,563 participants were diagnosed with CUD. Three quarters of cases were in men; there were 45,327 incident cases of schizophrenia during the study period. The researchers estimate that in 2021, about 15% of schizophrenia cases among males aged 16 to 49 could have been avoided by preventing CUD, compared with 4% among females in this age range. For young men aged 21 to 30, the proportion of preventable schizophrenia cases related to CUD may be as high as 30%, the authors report.”
Editors Note: Other data also support an increased risk for bipolar disorder in those abusing cannabis. The notion that cannabis use carries few risks is baloney. Making pot legal does not make it safe.
Low Frequency rTMS for Treatment-Resistant Auditory Hallucinations in Schizophrenia
Highlights from Posters Presented at the Society of Biological Psychiatry Meeting, April 27-29, 2023 in San Diego:
J. Brunelin gave patients “30 sessions of 1 Hz rTMS (repetitive Transcranial magnetic stimulation) over 3 weeks (360 pulses per sessions delivered with 60 sec ‘on’ and 30 sec ‘off’ at 110% of the resting motor threshold, 2 sessions per day). Stimulations were applied over the left temporoparietal junction.” Severity of auditory verbal hallucinations decreased (p=0.003) including in the 9 patients included with clozapine-resistant symptoms.
Young Men at Highest Schizophrenia Risk From Cannabis Abuse
Roughly 15% of schizophrenia cases among young males may be preventable by avoiding cannabis use disorder (CUD). Not only does cannabis abuse markedly increase the risk of schizophrenia, its use has transgenerational effects such that offspring from a cannabis user are more prone to use opiates.
Editors Note: Youngsters need to know two things.
1. Any supposedly legitimate drug bought on line may look like the real thing, but it is all-too-often laced with fentanyl which can kill someone in 5 minutes. No street-bought drug is safe, no matter how real it looks.
2. Marijuana will not kill you, but can make you psychotic for the rest of your life. The widely circulated notion that pot is safe is just a conspiracy by the plant growers to make money and by politicians who are ignorant of the facts. Pot doubles the rate of paranoia in the general population and if you have a good functioning genetic (val158val) version of COMT, this works too well to deplete dopamine in the prefrontal cortex and further increases the risk of paranoia and psychosis.
Cannabidiol (CBD) does not make cannabis safer
Amir Englund et al reported in Neuropsychopharmacology in A randomised, double-blind, cross-over trial of cannabis with four different CBD:THC ratios that CBD did not protect against the adverse effect of THC. These included impaired delayed verbal recall ( p?=?0.001) and induced positive psychotic symptoms on the PANSS ( p?=?2.41?×?10–5).
Editors Note: Not only does marijuana impair memory, it is a risk factor the onset of bipolar disorder and schizophrenia. When pot is used by a person with a unipolar or bipolar mood disorder, there are increases in depression and anxiety and an overall less favorable course of illness. If a person with a mood disorder uses heavy amounts of marijuana, they could consider buying N-acetylcysteine (NAC) 500mg and increasing the dose to 1,000mg twice a day within a week as this has been shown to decrease drug use compared to placebo in adolescents and young adults using and abusing pot. Most people who sell pot, are not well-informed about its dangers and just want to make money.
A Novel Drug Shows Promise in the Treatment of Negative Symptoms of Schizophrenia
At a recent scientific meeting, Kenneth Koblan, Chief Scientific Officer at Sunovion Pharmaceuticals, Inc. reported on a new drug in development, SEP-363856, and its effects on negative symptoms of schizophrenia.
In both a 4-week double-blind study of participants with acute schizophrenia and in an open (non-blind) 6-month extension study, SEP-363856 was effective on negative symptoms. In the placebo-controlled acute study, those randomized to 50mg or 75mg of the drug showed improvement of moderate effect size in the following symptoms: blunted affect, avolition, anhedonia, asociality, and alogia. In the extension study, which consisted of 26 weeks of treatment with flexible doses (25/50/75 mg/day) of SEP-365846, patients improved further on multiple scales measuring negative symptoms.
SEP-363856 is a novel trace amine receptor 1 (TAAR1) agonist with serotonin 5-HT1A activity. Koblan and colleagues concluded, “These results suggest that activation of the TAAR1 receptor by SEP-363856, in the absence of D2 receptor blockade, may represent a promising approach to the treatment of negative symptoms in schizophrenia.”
Environment Can Leave “Molecular Scars” Via Epigenetic Processes
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.
New Type of Antipsychotic Drug for Schizophrenia Looks Promising
In a 2020 article in the New England Journal of Medicine, researcher Kenneth S. Koblan and colleagues described a new type of antipsychotic drug treatment for schizophrenia. Almost all other antipsychotic drugs block dopamine D2 receptors, while atypical antipsychotics also block the serotonin 5HT2 receptor. They are described as antagonists at these receptors.
In contrast, the new drug is an agonist or activator of two different receptors. The drug SEP-363856 (also called SEP-856) activates the trace amine–associated receptor 1 (TAAR1) and 5-hydroxytryptamine (or serotonin) type 1A (5-HT1A) receptors.
Blocking D2 receptors can cause Parkinson’s-like symptoms (such as tremor, masked faces, and impaired movement or speech) and other extrapyramidal side effects (such as slurred speech, slow movements, or restless legs.) In contrast, SEP-856 seems to have a better side effects profile than these types of drugs while also being highly effective.
Patients with an acute exacerbation of schizophrenia were assigned to receive either placebo or once-daily treatment with SEP-856 (either 50mg or 75mg) for four weeks. A total of 120 patients received SEP-856 while 125 received placebo.
Compared to the placebo group, the SEP-856 group showed significantly greater reductions on a scale of positive and negative symptoms of schizophrenia by the end of the four weeks. Side effects included some sleepiness and gastrointestinal symptoms, but the incidence of extrapyramidal symptoms and changes in the levels of lipids, glycated hemoglobin, and prolactin were similar in both groups. There was one sudden death from cardiac causes in the SEP-856 group, which was not thought to be drug-related.
Editor’s Note: This drug acting on trace amine–associated receptor 1 (TAAR1) and 5HT1A receptors could herald a new and better tolerated type of antipsychotic. It is also being studied for psychosis in Parkinson’s disease. Since all of the antipsychotics that treat schizophrenia have also shown antimanic efficacy, we look forward to future studies of this unique drug in patients with mania.
One Hit of THC Tied to Psychotic Symptoms in Adults with No History of Mental Illness
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.
