China, where things tend to be big, even their clinical trials
A short while ago we looked at the possible mechanisms behind a reader’s successful experience in use of Mirtazapine (Remeron) in autism, then being prescribed to increase appetite.
Mirtazapine is a tricyclic antidepressant, meaning it is very closely related to first generation antihistamines, but it has numerous other effects; more of that later.
Folate is vitamin B9. Folic acid is synthetically produced, and used in fortified foods and supplements on the theory that it is converted into folate, which may not be the case.
It appears that in both schizophrenia and autism there is a family of possible folate dysfunctions that range from minor to severe. The mild dysfunction responds to a small supplement of folate, while the severe dysfunction requires a much larger supplement of folate.
Roger, another reader of this blog has the more severe dysfunction called Cerebral Folate Deficiency (CFD) and this condition is best studied by Vincent Ramaekers (Department of Pediatric Neurology and Center of Autism, University Hospital Liege) and Richard Frye at the Arkansas Children’s Hospital.
Cerebral folate deficiency as diagnosed by Ramaekers/Frye is extremely rare.
In a previous post we looked at Biotin (vitamin B7) and we saw that while biotin/biotinidase deficiency is technically extremely rare, a partial deficiency seems to exist in about 5% of people with autism.
Both severe biotin/biotinidase deficiency and partial biotin/biotinidase deficiency responds well to high dose biotin supplementation.
Without going into the details of Folate Receptor Autoantibodies (FRAs), it is clear that Ramaekers has found the same condition in both Schizophrenia and Autism.
The milder folate dysfunction is very well known in schizophrenia.
The Chinese Trial
On the basis that bigger is better, a clinical trial is underway in China on 330 subjects with Schizophrenia to measure the benefit of Mirtazapine and/or folate as an add-on therapy.
I was quite surprised to come across this trial.
Today’s Post
Today’s post will look at the known effects of Mirtazapine and folate in schizophrenia and also the role folate plays in human biology.
There are lab tests that you could make to check for Folate dysfunction, just as there are for Biotin dysfunction.
The standard therapy for Cerebral Folate Deficiency is the prescription drug leucovorin, normally used in cancer therapy. There is also a supplement called Metafolin (Levomefolate calcium) that should have a very similar, if not identical, effect. Metafolin is produced by Merck and sold to supplement companies on the basis that it is only sold in low doses. Metafolin appears more than your average “supplement”.
Another producer of Levomefolate calcium, is Pamlab; they sell it as a treatment for memory loss and peripheral neuropathy. Pamlab was purchased by Nestlé Health Science in 2013; the Swiss tend to know what they are doing.
Schizophrenia
Schizophrenia overlaps significantly with autism in terms of its genetic origin.
Interestingly, people with schizophrenia may have a high rate of irritable bowel syndrome, but they often do not mention it unless specifically asked.
To better understand the clinical trials you need to know that the schizophrenia is a spectrum like autism with three main problem areas:-
Positive symptoms
These are symptoms that most individuals do not normally experience but are present in people with schizophrenia. They can include delusions, disordered thoughts and speech, and tactile, auditory, visual, olfactory and gustatory hallucinations, typically regarded as manifestations of psychosis. Hallucinations are also typically related to the content of the delusional theme. Positive symptoms generally respond well to medication.
Negative symptoms
Cognitive dysfunction
The extent of the cognitive deficits an individual experiences is a predictor of how functional an individual will be, the quality of occupational performance, and how successful the individual will be in maintaining treatment. The presence and degree of cognitive dysfunction in individuals with schizophrenia has been reported to be a better indicator of functionality than the presentation of positive or negative symptoms
Effective psychiatric drugs only exist for the positive symptoms, they do not exist for the negative symptoms or the cognitive dysfunction.
Folate Deficiency in Schizophrenia
Folate treatment in schizophrenia is linked to improvement in the negative symptoms that are normally untreatable.
Studies are mixed, but subgroups clearly exist in schizophrenia where folate supplementation improved well-being.
The rare severe dysfunction which is Cerebral Folate Deficiency is shown to exist in schizophrenia.
Participants were all taking antipsychotic medications – which have been shown to alleviate positive symptoms, such as hallucinations and delusions, but not negative symptoms – and were randomized to receive daily doses of either folate and vitamin B12 or a placebo for 16 weeks. Every two weeks their medical and psychiatric status was evaluated, using standard symptom assessment tools along with measurements of blood levels of folate and homocysteine, an amino acid that tends to rise when folate levels drop. Nutritional information was compiled to account for differences in dietary intake of the nutrients. Participants' blood samples were analyzed to determine the variants they carried of MTHFR and three other folate-pathway genes previously associated with the severity of negative symptoms of schizophrenia.
Among all 140 participants in the study protocol, those receiving folate and vitamin B12 showed improvement in negative symptoms, but the degree of improvement was not statistically significant compared with the placebo group. But when the analysis accounted for the variants in the genes of interest, intake of the two nutrients did provide significant improvement in negative symptoms, chiefly reflecting the effects of specific variants in MTHFR and in a gene called FOLH1. Variants in the other two genes studied did not appear to have an effect on treatment outcome.
CONCLUSIONS:
This study showed that folate deficiency is common in schizophrenic patients; therefore, it is important to pay attention to folate levels in these patients.
The Role of Folate/vitamin B9 in Human Biology
Vitamin B9 is essential for numerous bodily functions. Humans cannot synthesize folates de novo; therefore, folic acid has to be supplied through the diet to meet their daily requirements. The human body needs folate to synthesize DNA, repair DNA, and methylate DNA as well as to act as a cofactor in certain biological reactions.
Folic acid is synthetically produced, and used in fortified foods and supplements on the theory that it is converted into folate. To be used it must be converted to tetrahydrofolate (tetrahydrofolic acid) by dihydrofolate reductase (DHFR). Increasing evidence suggests that this process may be slow in humans.
Note betaine below, which is also used to treat Cerebral Folate Deficiency, along with NAC.
Folic Acid, Folinic Acid and Folate
The terminology is confusing; what we want is folate, but there are several ways to get it. Folic acid does not appear to be a good way. Folinic acid, Levomefolic acid and Levomefolate calcium look to be the most effective supplements.
Here is a brief summary from Wikipedia:_
Folinic acid or leucovorin, generally administered as the calcium or sodium salt (calcium folinate, sodium folinate, leucovorin calcium, leucovorin sodium), is an adjuvant used in cancer chemotherapy involving the drug methotrexate. It is also used in synergistic combination with the chemotherapy agent 5-fluorouracil.
Folinic acid (also called 5-formyltetrahydrofolate) was first discovered in 1948 as citrovorum factor and occasionally is still called by that name. Folinic acid should be distinguished from folic acid (vitamin B9). However, folinic acid is a vitamer for folic acid, and has the full vitamin activity of this vitamin.
Levomefolic acid is the primary biologically active form of folic acid used at the cellular level for DNA reproduction, the cysteine cycle and the regulation of homocysteine. It is also the form found in circulation and transported across membranes into tissues and across the blood-brain barrier. In the cell, L-methylfolate is used in the methylation of homocysteine to form methionine and tetrahydrofolate (THF). THF is the immediate acceptor of one carbon units for the synthesis of thymidine-DNA, purines (RNA and DNA) and methionine. The un-methylated form, folic acid (vitamin B9), is a synthetic form of folate, and must undergo enzymatic reduction by methylenetetrahydrofolate reductase (MTHFR) to become biologically active.
It is synthesized in the absorptive cells of the small intestine from polyglutamylated dietary folate. It is a methylated derivative of tetrahydrofolate. Levomefolic acid is generated by MTHFR from 5,10-methylenetetrahydrofolate (MTHF) and used to recycle homocysteine back to methionine by 5-methyltetrahydrofolate-homocysteine methyltransferase(MTR) also known as methionine synthase (MS).
Levomefolic acid (and folic acid in turn) has been proposed for treatment of cardiovascular disease and advanced cancers such as breast and colorectal cancers. It bypasses several metabolic steps in the body and better binds thymidylate synthase with fDump, a metabolite of the drug fluorouracil.
Levomefolate calcium, a calcium salt of levomefolic acid, is sold under the brand names Metafolin (a registered trademark of Merck KGaA) and Deplin (trademark of Pamlab, LLC). Methyl folate can be bought at online stores or in some chemists though without a prescription.
A good choice seems to be Metafolin, like in this product:-
Folate and Autism
We know from Roger and Frye/Ramaekers that the rare condition condition Cerebral folate deficiency (CFD) exists in autism, but what about the more widespread milder dysfunction like that found in schizophrenia?
As usual the level of knowledge in autism is less than that in schizophrenia. The paper below concludes that when it comes to autism, not much is known.
Autism spectrum disorders (ASD) consist in a range of neurodevelopmental conditions that share common features with autism, such as impairments in communication and social interaction, repetitive behaviors, stereotypies, and a limited repertoire of interests and activities. Some studies have reported that folic acid supplementation could be associated with a higher incidence of autism, and therefore, we aimed to conduct a systematic review of studies involving relationships between this molecule and ASD. The MEDLINE database was searched for studies written in English which evaluated the relationship between autism and folate. The initial search yielded 60 potentially relevant articles, of which 11 met the inclusion criteria. The agreement between reviewers was κ = 0.808. The articles included in the present study addressed topics related to the prescription of vitamins, the association between folic acid intake/supplementation during pregnancy and the incidence of autism, food intake, and/or nutrient supplementation in children/adolescents with autism, the evaluation of serum nutrient levels, and nutritional interventions targeting ASD. Regarding our main issue, namely the effect of folic acid supplementation, especially in pregnancy, the few and contradictory studies present inconsistent conclusions. Epidemiological associations are not reproduced in most of the other types of studies. Although some studies have reported lower folate levels in patients with ASD, the effects of folate-enhancing interventions on the clinical symptoms have yet to be confirmed.
Given the anecdotal evidence, including from our reader Seth, and the close biological relationship between autism and schizophrenia it seems pretty clear that a sub-group of people with autism do have a folate dysfunction that should respond to supplementation.
How big this subgroup is remains to be seen. For biotin it is about 5%, for vitamin B12 it about 10%. Given it is known that MTHFR mutations are very common in autism, for example 23% were found to have the homozygous mutation 677CT allele (see the study below), it is very likely to be a sizeable group. MTHFR is only one of the genes that could cause a folate problem.
A trial of metafolin could be a rewarding experience for some.
Back to the second half of that big Chinese Trial - Mirtazapine
There is a wealth of research that looks into the benefit of Mirtazapine in schizophrenia. I choose to highlight a study from Finland because it is extremely comprehensive.
It has been reported earlier, from another part of this study, that clear-cut differences in all PANSS subscales and a large effect size of 1,00 (CI95% 0,23-1,67) on the PANSS total scores resulted from mirtazapine treatment when compared with a placebo in both within group and between group analyses during the double-blind phase (Joffe et al. 2009). In the open label phase, patients who switched to mirtazapine treatment demonstrated a clinical improvement in the same manner as their mirtazapine-treated counterparts in the double-blind phase. Prolonged treatment with mirtazapine led to more prominent improvements in clinical parameters than short-term treatment. A trend towards improvement was seen in all measured parameters, therefore providing more evidence of mirtazapine’s beneficial effect on schizophrenia symptoms.
The actual mechanism for a potential neurocognitive enhancing effect of mirtazapine in schizophrenia remains unknown, but it may be elucidated from its receptor binding profile. Like most SGAs, mirtazapine could also increase prefrontal dopaminergic and noradrenergic activity via 5-HT2A or 5-HT2C receptor blockade, as demonstrated in animal models (Liegeois et al. 2002; Meneses 2007; Zhang et al. 2000), and thus improve neurocognitive performance. Secondly, 5-HT3 receptor modulation by mirtazapine could also improve neurocognition (Akhondzadeh et al. 2009), presumably through increased release of acetylcholine (Ramirez et al. 1996). Thirdly, mirtazapine might improve neurocognition as a result of the indirect agonism of 5-HT1A receptors (Sumiyoshi et al. 2007). Moreover, mirtazapine is a more potent alpha-2 receptor antagonist than clozapine, which may explain its additional neurocognition-enhancing effect, even if it is added to clozapine (as in the study reported by Delle Chiae et al. 2007). The alpha-2 receptors remain an important target for neurocognitive research and its down-regulation may enhance neurocognition through a noradrenaline-mediated modulation of response to environmental stimuli (Friedman et al. 2004). Furthermore, alpha-2 receptor antagonism seems to boost hippocampal neurogenesis (Rizk et al. 2006). Also, mirtazapine may actually boost levels of brain-derived neurotrophic factor (BDNF) Rogoz et al. 2005), which is a major mediator of neurogenesis 62 and neuroplasticity. Correspondingly, those who suffer from schizophrenia often have abnormally low BDNF serum levels (Rizos et al. 2008).
During the 6-week extension phase, patients who had previously received six weeks of mirtazapine and those on placebo both showed significant improvement on several neurocognitive tests. Twelve-week mirtazapine treatment demonstrated better neurocognitive outcome than just six weeks of mirtazapine treatment, as evaluated by Stroop Dots time and TMT-B, number of mistakes, which are associated with general improvement in mental speed/attention control and executive functions. Twelve-week mirtazapine add-on to antipsychotic treatment indicated additional neurocognitive improvements of just six weeks, which demonstrates a progressive therapeutic effect.
In earlier posts on Mirtazapine/Remeron I raised various possible modes of action and other readers added their further ideas.
The table below lists some of the possible modes of action. I declare a bias towards the importance of histamine, but clearly many more things are involved.
Mirtazapine has been trialed for a vast range of conditions:
Mirtazapine is an effective antidepressant with unique mechanisms of action. It is characterized by a relatively rapid onset of action, high response and remission rates, a favorable side-effect profile, and several unique therapeutic benefits over other antidepressants. Mirtazapine has also shown promise in treating some medical disorders, including neurologic conditions, and ameliorating some of the associated debilitating symptoms of weight loss, insomnia, and postoperative nausea and vomiting.
And even Fibromyalgia, which I did suggest was the “almost autism” for females:-
In a 6-week open-label trial of mirtazapine, 54% of the 26 fibromyalgia patients who completed the study demonstrated a clinically significant reduction in pain intensity and in mean weekly dosage of acetaminophen. Additionally, there was a significant improvement in sleep quality and somatic symptoms, including cold extremities, dry mouth, sweating, dizziness, and headache. Of note, the magnitude of reduction in major fibromyalgia symptoms was significantly correlated with the magnitude of reduction in depression
Mirtazapine in Autism
In the new trial of Mirtazapine in autism they have chosen to focus on anxiety. That looks odd to me given the very wide scope of benefits seen in schizophrenia and the feedback of our reader who asked why Remeron was working wonders with his child.
As is often the case, this trial at Massachusetts General Hospital uses doses that are extremely high. Given the numerous effects of this drug it is highly likely that the effect may be completely different at higher/lower doses.
This study will determine the effectiveness of mirtazapine in reducing anxiety in children with autistic disorder, Asperger's disorder and Pervasive Developmental Disorder.
The starting dose for subjects is 7.5 mg daily. The maximum daily dose will be 45 mg.
I am very much in agreement with the readers of this blog using Mirtazapine at a lower dose.
As the schizophrenia trial showed, the effect grows over time, so better to try a low dose of 5mg for two months than race up to 45mg.
