Methylenetetrahydrofolate reductase (MTHFR) genetic variation and major depressive disorder prognosis: A five-year prospective cohort study of primary care attendees

Discovery of Methylenetetrahydrofolate Reductase (MTHFR) Deficiency in Individuals With Common Psychiatric Comorbidities: A Retrospective Case Review

INTRODUCTION

A retrospective analysis was conducted of a data set collected in an outpatient behavioral health clinic to assess medication metabolism and methylenetetrahydrofolate reductase (MTHFR) and to see if there was a correlation with certain diagnoses and/or gender.

METHOD

The outpatient routine completed genetic testing on their patients and the test results were later collected through a third-party company, which completed the pharmacogenomic test analyzing genetic variations in DNA, medication metabolism, and an MTHFR deficiency.

RESULTS

This study reviewed 186 patients seen in an outpatient setting who were tested for an MTHFR deficiency and compared their psychiatric diagnoses and the number of failed medication attempts. Of those 186 patients, 77 had normal MTHFR enzyme function, 85 were found to have a moderate MTHFR deficiency, and 24 had a severe MTHFR deficiency. Those with a severe MTHFR deficiency had a higher number of medication trials as compared to those without the deficiency and there were overall more patients with a moderate MTHFR deficiency in this data set.

CONCLUSION

Currently, MTHFR deficiency is not commonly tested due to lack of insurance coverage and provider knowledge, and due to the cost of the test itself. Thus, the diagnosis can often be missed.

The potential use of folate and its derivatives in treating psychiatric disorders: A systematic review

OBJECTIVES

To examine the strengths and limitations of existing data to provide guidance for the use of folate supplements as treatment, with or without other psychotropic medications, in various psychiatric disorders. To identify area for further research in terms of the biosynthesis of mechanism of folate and genetic variants in metabolic pathway in human.

METHODS

A systematic review of published literature following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, to assess whether folate supplements are beneficial in certain psychiatric disorders (depression, bipolar disorder, schizophrenia, autism spectrum disorder, and attention deficit hyperactivity disorder). Methodology of this review is registered with Prospero (Registration number CRD 42021266605).

DATA SOURCES

Eligible studies were identified using a systematic search of four electronic databases: Embase, Pubmed, PsycINFO, and Cochrane. The search strategy covered the time period from 1974 to August 16th, 2021. Therefore, this review examines randomized control trials or open-label trials completed during this period.

RESULTS

We identified 23 studies of folate supplements in various psychiatric disorders for critical review. Of these, 9 studies investigated the efficacy of folate supplements in major depressive disorders, 5 studies in schizophrenia, 6 studies in autism spectrum disorder, 2 studies in bipolar affective disorder and 1 study in attention deficit hyperactive disorder. The most consistent finding association of oral levomefolic acid or 5-methylfolate with improvement in clinical outcomes in mental health conditions as mentioned above, especially in major depressive disorder (including postpartum and post-menopausal depression), schizophrenia, autism spectrum disorder, attention deficit hyperactivity disorder and bipolar affective disorder. Folate supplements were well tolerated.

LIMITATION

Our results are not representative of all types of studies such as case reports or case series studies, nor are they representative of the studies conducted in languages that are not in English or not translated in English.

CONCLUSION

Increasing evidence from clinical trials consistently demonstrate folate supplements, especially levomefolic acid or 5-methylfolate, may improve clinical outcomes for certain psychiatric diseases, especially as an adjunct pharmacotherapy with minimal side effects.

Association Between MTHFR C677T Polymorphism and Susceptibility to Autism Spectrum Disorders: A Meta-Analysis in Chinese Han Population

Prior studies have examined the influence of MTHFR C677T on autism susceptibility, however, there are no consensus conclusions and specific analyses of a Chinese population. This meta-analysis included a false-positive report probability (FPRP) test to comprehensively evaluate the association of MTHFR C677T polymorphism with autism susceptibility among a Chinese Han population. A large-scale literature retrieval was conducted using various databases including PubMed, Embase, Wan Fang, and the Chinese National Knowledge Infrastructure (CNKI) up to July 31, 2020, with a total of 2,258 cases and 2,073 controls included. The strength of correlation was assessed by odds ratios (ORs) and 95% confidence intervals (95% CIs). MTHFR C677T showed a significant correlation with increased ASD susceptibility under all genetic models (T vs. C, OR = 1.89, 95% CI 1.28 to 2.79; TT vs. CC: OR = 2.44, 95% CI 1.43 to 4.15; CT vs. CC, OR = 1.73; 95% CI 1.19 to 2.51; CT + TT vs. CC: OR = 2.03, 95% CI 1.31 to 3.15; TT vs. CT + CC, OR = 1.95, 95% CI 1.21 to 3.13). Stratification analysis by region also revealed a consistent association in the Northern Han subgroup, but not in the Southern Han subgroup. Pooled minor allele frequency (MAF) of 30 studies were 45% in Northern Han and 39% in Southern Han. To avoid a possible "false positive report," we further investigated the significant associations observed in the present meta-analysis using the FPRP test, which consolidated the results. In conclusion, MTHFR C677T polymorphism is associated with the increased risk of autism in China, especially in Northern Han. For those mothers and children who are generally susceptible to autism, prenatal folate and vitamin B12 may reduce the risk that children suffer from autism, especially in Northern Han populations. In the future, more well-designed studies with a larger sample size are expected.

L-Methylfolate Calcium Supplementation in Adolescents and Children: A Retrospective Analysis

Previous studies have shown l-methylfolate to be a safe and beneficial therapy for neuropsychiatric conditions, including major depressive disorder and schizophrenia in adults. The purpose of this study was to assess safety and describe patient experience using l-methylfolate calcium in a real-world pediatric and adolescent population. A retrospective chart review of patients (7 to 20 y of age, mean age 16 y) prescribed l-methylfolate calcium at a psychiatry clinic in Amherst, NY, between January 1, 2010 and November 10, 2015 was conducted. Patients to whom l-methylfolate calcium 15 mg/d (n=139) or 7.5 mg/d (n=7) was administered were identified; 44 patients who were prescribed but to whom l-methylfolate calcium was not administered were included as a comparator population. Common neuropsychiatric diagnoses included anxiety disorders (68% in the treatment population vs. 50% in the comparator population) and mood disorders (57% in the treatment population vs. 52% in the comparator population). Antidepressants (69% vs. 55%) and mood stabilizers or antiepileptic drugs (63% vs. 57%) were frequently prescribed in combination with l-methylfolate calcium. Adverse events occurred less frequently in the treated population, possibly due to the addition of l-methylfolate calcium (10% vs. 25%, P=0.02). The most common adverse events in the treated population were impaired sleep (5 patients) and increased anxiety (3 patients). Rates of laboratory abnormalities did not differ significantly between the treated and comparator populations (P=0.13). Positive subjective treatment experiences were reported by 22.5% of treated patients and negative subjective treatment experiences were reported by 5.4% of treated patients. L-methylfolate calcium was well-tolerated in a pediatric/adolescent population and may provide benefits for patients with a range of neuropsychiatric conditions.

Methylenetetrahydrofolate reductase and psychiatric diseases

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme for the critical process of one-carbon metabolism involving folate and homocysteine metabolisms. It is known that some polymorphism of MTHFR would result in reduction of MTHFR enzyme activity as well as DNA methylation process, later shown to have significant impacts in various psychiatric diseases. However, it is unclear whether the polymorphism of MTHFR could be an independent or an add-on risk factor for specific psychiatric symptoms, such as anxiety, depression, positive, or negative symptoms of schizophrenia, or acts as risk factor for specific psychiatric disorders, such as schizophrenia, major depression, autisms, and bipolar disorders. It is also understudied on whether folate supplements could be an effective treatment for psychiatric patients with defect MTHFR activity. In this review, we not only gathered the most recent discoveries on MTHFR polymorphism and related DNA methylation in various psychiatric disorders, but also highlighted the potential relationships between MTHFR activity and implication of folate-related function in specific mental diseases.

MTHFR gene methylation is associated with perceived stress in healthy young adults

BACKGROUND

Epigenetic factors have been identified in the past years as interesting candidates for psychiatric disorders and related endophenotypes. It has been found that the methylenetetrahydrofolate reductase (MTHFR) gene is associated with major depressive disorder, and the aim of the current study was to examine the possible association between perceived stress and MTHFR methylation, taking into account depressive symptoms as a covariate.

PARTICIPANTS AND METHODS

Seventy-eight healthy Colombian participants (mean age=20.9 years; SD=3.0) were evaluated with the Perceived Stress Scale and with the Patient Health Questionnaire-9 for depressive symptomatology. MTHFR methylation levels were measured with a methylation-sensitive high-resolution melting method. A multiple regression analysis (adjusting for age, sex, and depressive symptoms) was carried out to assess the association between MTHFR methylation and perceived stress scores.

RESULTS

We found a significant inverse correlation between MTHFR methylation levels and perceived stress scores (r=-0.502; P=5.9×10(-5)), which remained significant after being adjusted for age, sex, and depressive symptomatology.

CONCLUSION

To our knowledge, this is the first study that reports an association between perceived stress and MTHFR methylation levels. This report adds evidence to the emerging role of epigenetic changes in endophenotypes related to affective disorders.

Helicobacter pylori moderates the association between 5-MTHF concentration and cognitive function in older adults

Objective

To explore potential interactions between folate-cycle factors and Helicobacter pylori seropositivity in the prediction of cognitive function.

Methods

We used data obtained from the 1999–2000 continuous National Health and Nutrition Examination Survey produced by the United States’ Centers for Disease Control and Prevention. Using Ordinary Least Squares regression, we tested for associations between multiple folate-cycle factors, Helicobacter pylori seropositivity, and cognitive function assessed by the digit symbol coding subtest of the Wechsler Adult Intelligence Scale-III. We then tested for interactions between each of the folate-cycle factors and Helicobacter pylori in the prediction of cognitive function.

Results

Although Helicobacter pylori seropositivity, 5-methyltetrahydrofolate, vitamin B-12, and homocysteine were not associated with performance on the digit symbol coding task, Helicobacter pylori seropositivity interacted with 5-methyltetrahydrofolate concentration to predict performance on the digit symbol coding task. The Helicobacter pylori seropositive group performed worse on the digit symbol coding task as 5-methyltetrahydrofolate concentration decreased.

Conclusion

The interaction between Helicobacter pylori seropositivity and reduced folate-cycle factor 5-methyltetrahydrofolate might impair aspects of cognitive function.

Methylenetetrahydrofolate Reductase A1298C Polymorphism and Major Depressive Disorder

Major depressive disorder (MDD) is a disorder that carries significant psychosocial and economic implications. Research efforts have focused on identifying biomarkers that can aid in the prediction, diagnosis, and efficacious treatment of MDD. Most of this focus has been placed on a polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene, C677T. MTHFR C677T is screened during MDD diagnosis in many protocols. However, MTHFR C667T poses conflicting data in various ethnic groups and geographic populations calling into question its utility. Another polymorphism, MTHFR A1298C, has often taken the back-seat to MTHFR C677T in respect to research focus. MTHFR A1298C is implicated in irregular homocysteine metabolism and aberrant folate cycles and, through this, it may play a role as either a driver in the development of MDD or as a predictive or diagnostic marker, possibly in combination with C677T. The number of studies evaluating MTHFR A1298C and the power of those studies is lacking and thus larger studies are required to confirm the association between this polymorphism and MDD.

Epigenetics, nutrition and mental health. Is there a relationship?

Many aspects of human development and disease are influenced by the interaction between genetic and environmental factors. Understanding how our genes respond to the environment is central to managing health and disease, and is one of the major contemporary challenges in human genetics. Various epigenetic processes affect chromosome structure and accessibility of deoxyribonucleic acid (DNA) to the enzymatic machinery that leads to expression of genes. One important epigenetic mechanism that appears to underlie the interaction between environmental factors, including diet, and our genome, is chemical modification of the DNA. The best understood of these modifications is methylation of cytosine residues in DNA. It is now recognized that the pattern of methylated cytosines throughout our genomes (the 'methylome') can change during development and in response to environmental cues, often with profound effects on gene expression. Many dietary constituents may indirectly influence genomic pathways that methylate DNA, and there is evidence for biochemical links between nutritional quality and mental health. Deficiency of both macro- and micronutrients has been associated with increased behavioural problems, and nutritional supplementation has proven efficacious in treatment of certain neuropsychiatric disorders. In this review we examine evidence from the fields of nutrition, developmental biology, and mental health that supports dietary impacts on epigenetic processes, particularly DNA methylation. We then consider whether such processes could underlie the demonstrated efficacy of dietary supplementation in treatment of mental disorders, and whether targeted manipulation of DNA methylation patterns using controlled dietary supplementation may be of wider clinical value.

Challenging Treatment-Resistant Major Depressive Disorder: A Roadmap for Improved Therapeutics

Major depressive disorder (MDD) is associated with a significant burden and costs to the society. As remission of depressive symptoms is achieved in only one-third of the MDD patients after the first antidepressant trial, unsuccessful treatments contribute largely to the observed suffering and social costs of MDD. The present article provides a summary of the therapeutic strategies that have been tested for treatment-resistant depression (TRD). A computerized search on MedLine/PubMed database from 1975 to September 2014 was performed, using the keywords “treatment-resistant depression”, “major depressive disorder”, “adjunctive”, “refractory” and “augmentation”. From the 581 articles retrieved, two authors selected 79 papers. A manual searching further considered relevant articles of the reference lists. The evidence found supports adding or switching to another antidepressant from a different class is an effective strategy in more severe MDD after failure to an initial antidepressant trial. Also, in subjects resistant to two or more classes of antidepressants, some augmentation strategies and antidepressant combinations should be considered, although the overall response and remission rates are relatively low, except for fast acting glutamatergic modulators. The wide range of available treatments for TRD reflects the complexity of MDD, which does not underlie diverse key features of the disorder. Larger and well-designed studies applying dimensional approaches to measure efficacy and effectiveness are warranted.

The Brain-Derived Neurotrophic Factor Val66Met Polymorphism Moderates the Effects of Childhood Abuse on Severity of Depressive Symptoms in a Time-Dependent Manner

Cross-sectional studies have demonstrated that the brain-derived neurotrophic factor (BDNF) Val66Met single-nucleotide polymorphism moderates the association between exposure to negative life events and depression outcomes. Yet, it is currently unclear whether this moderating effect is applicable to positive life events and if the moderating effect is stable over time. To address these gaps in the literature, we examined clinical and BDNF genotypic data from a 5-year prospective cohort of 310 primary care attendees. Primary care attendees were selected based on existence of depressive symptoms at screening. Depressive symptoms were assessed at baseline and annually for 5 years post-baseline using the Primary Care Evaluation of Mental Disorders Patient Health Questionnaire-9 (PHQ-9). Linear mixed models assessed differences in depressive symptom severity over the 5-year follow-up period by BDNF Val66Met and history of life events, both negative and positive. Analysis identified a novel three-way interaction between the BDNF Val66Met polymorphism, history of severe childhood abuse, and time. Post hoc analysis stratified by time showed a two-way interaction between Val66Met and severe childhood abuse at baseline that was not detectable at any other time point. An interaction between Val66Met and positive life events was not detected. Our longitudinal results suggest that the BDNF Val66Met polymorphism moderates the depressive symptom severity experienced by those with a history of severe childhood abuse but does so in a time-dependent manner. Our results further support the notion that gene-environment-depression interactions are dynamic and highlight the importance of longitudinal assessment of these interactions. Given these novel longitudinal findings; replication is required.

CT genotype of 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism is protector factor of major depressive disorder in the Tunisian population: a case control study

BACKGROUND

Major depressive disorder (MDD) is a common psychiatric disorder with considerable mortality. Death from unnatural causes, largely suicidal or quasi-suicidal, has a particularly high risk for the functional disorders, especially depression and schizophrenia. One of the prospective risk factors for this disease is hyperhomocysteinemia and folate deficiency. The methylenetetrahydrofolate reductase (MTHFR) gene encodes for a 5-methylenetetrahydrofolate reductase involved in folate metabolism and neurotransmitter synthesis. The aim of this research is to study the association between the C677T polymorphism of MTHFR gene and depression in Tunisian population, to explore their relationship with clinical and therapeutic characteristics of this disease. And it may lead to discover a novel marker to identify a patient with a higher risk of development of depressive disorder to be. This marker can be used for better therapeutic management and prevent disease installation.

METHODS

Our study included 208 depressive patients, 187 controls aged between 44.1 ± 13.5 and 38.9 ± 13.2 years, respectively. MTHFR gene polymorphisms were determined by PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism).

RESULTS

No significant difference was detected in the distribution of the genotype frequencies of MTHFR C677T polymorphisms (χ (2) = 5.443, df = 2, p = 0.066) between patients and controls. But when we study the risk of these genotypes, CT genotype is significantly more frequent in controls compared to patients, it may be a protection from depression (OR = 0.655, CI 95 % = 0.432-0.995, p = 0.047, OR* = 0.638, CI 95 %* = 0.415-0.983, p* = 0.04, before and after adjustment). Women, TT Genotype can increase four times the risk to be depressive. Addictive behavior seems to be associated with CT genotype and there was no significant association between clinical and therapeutic characteristics and this polymorphism.

CONCLUSION

This paper is the first study to prove that CT genotype of MTHFR C677T polymorphism may protect from depression and TT genotype seems to be associated with women's depression. Further studies are required with other polymorphisms and biochemical factors that must be investigated to clarify the implication of MTHFR C677T polymorphism in the pathophysiology of depression.

Epigenetics in Clinical Practice: Characterizing Patient and Provider Experiences with MTHFR Polymorphisms and Methylfolate

BACKGROUND

Observational research associating 5,10-methylenetetrahydrofolate reductase (MTHFR) polymorphisms with risk of autism, depression, cancer, and cardiovascular disease has led to increased diagnoses of MTHFR; however, doctors lack knowledge about safety, effectiveness, and clinical implications of MTHFR treatment. Treatment strategies are hypothetical and mechanistically based, including methylfolate with or without other B vitamins.

AIMS

This study was designed to formally describe patient and health care provider experiences with the diagnosis and clinical management of MTHFR.

METHODS

Guided by a structured interview guide, a qualitative study queried patients' and providers' observations regarding: testing indications, reaction to results, treatment protocols, and clinical response including adverse effects.

RESULTS

Thirty patients and 8 doctors participated. Patient themes included emotionality associated with diagnosis, classification of signs and symptoms, and challenges with treatment. They expressed confusion over their diagnosis, and frustration with the state of knowledge their providers had regarding MTHFR. Testing indications included: fatigue (21%), hormone imbalances (13%), and neurological symptoms (13%) including brain fog (8%). Patients reported improvements in physical (60%) and mental/behavioral symptoms (36%) following treatment. A minority of participants reported side effects, but they occurred in almost every body system and ranged in severity. Doctors relied on trial and error to determine treatment doses, frequency and components.

CONCLUSIONS

MTHFR testing results in variable clinical processes in domains related to delivery of diagnosis and prognosis, and therapeutic options. However, patients report largely positive experiences. Clinicians and patients would benefit from therapeutic algorithms based on rigorous research.

MTHFR: Genetic variants, expression analysis and COMT interaction in major depressive disorder

BACKGROUND

Methylenetetrahydrofolate reductase (MTHFR) genetic variations have been widely studied in major depressive disorder (MDD) and antidepressants outcome. An interaction with catechol-O-methyltransferase (COMT) has also been proved affecting depression. The aim of this study was to clarify the role of the most commonly studied single nucleotide polymorphisms (SNPs) of MTHFR gene in MDD and in treatment response mechanisms, along with the impact of the interaction with COMT.

METHODS

A total of 613 MDD patients, of whom 389 were classified as having treatment resistant depression (TRD), and 463 controls were enrolled. The A1298C, C677T and COMT Val158Met were genotyped. Genetic data were integrated with a transcriptional level analysis in peripheral blood cells (PBCs) and fibroblasts.

RESULTS

The A1298C CC homozygotes were more frequent in MDD patients compared to controls in women, increasing twice the genetic risk to develop depression. Moreover this genotype resulted in epistasis with COMT Met carriers in association with MDD. No significant effects were obtained concerning response to treatment. Transcriptional analyses highlighted a strong correlation between the mRNA levels of MTHFR in fibroblasts and COMT genotypes whereas no significant association with MDD was found. PBCs results revealed relevant influences of environmental factors.

LIMITATION

We did not measure folate and homocisteine levels.

CONCLUSION

This study showed the involvement of A1298C, Val158Met and their interaction in MDD. The transcriptional analyses supported the participation of COMT in the folate pathway, which partakes in the complex network of gene×gene and gene×environment interactions of MDD etiopathogenesis.

G-protein β3 subunit genetic variation moderates five-year depressive symptom trajectories of primary care attendees

BACKGROUND

Genetic variation in the G-protein β3 subunit (GNB3) has previously been associated with gene splicing that has been further linked to increased signal transduction and major depressive disorder. However, the effect of GNB3 genetic variation on depressive symptom trajectories is currently unknown. The aim of the present study is to examine whether genetic variation in GNB3 moderates depressive symptom trajectories among 301 primary care attendees enrolled in the Diagnosis, Management and Outcomes of Depression in Primary Care (diamond) prospective cohort study.

METHODS

Depressive symptoms were assessed using three measures: (1) DSM-IV criteria, (2) Primary Care Evaluation of Mental Disorders Patient Health Questionnaire-9 (PHQ-9), and (3) Center for Epidemiologic Studies Depression Scale (CESD). DSM-IV criteria were measured at baseline, 24, 36, 48, and 60 months post-baseline, whereas, PHQ-9 and CESD measurements were taken at baseline, 12, 24, 36, 48, and 60 months post-baseline. Two haplotype-tagging single nucleotide polymorphisms [rs5443 (C825T) and rs5440] spanning the GNB3 gene including ~1Kb upstream and downstream of the gene boundaries were genotyped.

RESULTS

Five-year PHQ-9 and CESD depressive symptom trajectories were moderated by rs5440. Carriers of the rs5440 GG genotype had more favourable depressive symptom trajectories compared to AG or AA genotype carriers. The rs5443 polymorphism did not moderate depressive symptom trajectories, regardless of the measure used.

LIMITATIONS

Generalizability to depressed populations outside of the primary care setting may be limited.

CONCLUSIONS

These results provide novel evidence suggesting genetic variation in the 5-prime region of GNB3 moderates depressive symptom trajectories among primary care attendees.