COMTVal158Met polymorphism is associated with ecstasy (MDMA)-induced psychotic symptoms in the Turkish population.

OBJECTIVES: To investigate catechol-O-methyltransferase (COMT) Val158Met gene polymorphism in MDMA use disorder (MUD) by comparing genotype distributions between MUD patients and healthy controls considering clinical parameters. METHODS: Eighty-two MUD patients' were consecutively admitted to the outpatient psychiatry clinic in May 2019-January 2020, and 95 healthy volunteers were included in the case-control study. We used the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) to determine COMT Val158Met polymorphism. RESULTS: The COMT Val158Met genotype distribution and allele frequencies of the MUD patient group were significantly different from the healthy control group. The Met/Met genotype (OR: 2.692; 95% Cl: 1.272-5.698; p=0.008) and Met allele frequencies (OR: 1.716; 95% Cl: 1.118-2.633; p=0.013) were significantly higher in the control group than in MUD patients. When the COMT Val158Met genotype and allele frequency distributions were compared between 2 groups according to the psychotic symptoms in the MUD patient group, the COMT Val158Met genotype distributions were significantly different between the groups of patients. The percentage of patients with the Val/Val genotype was significantly lower in MUD patients with a psychotic symptom than the MUD patients without a psychotic symptom (OR: 2.625; 95% Cl: 1.069-6.446; p=0.033). CONCLUSION: The COMT Val158Met gene polymorphism was found to be related to the MUD-diagnosed Turkish patients and MDMA-induced psychotic symptoms.

Cannabis Use and the Risk for Psychosis and Affective Disorders.

Objective: This review discusses the relationship between cannabis use and psychotic, bipolar, depressive, and anxiety disorders, as well as suicide. It summarizes epidemiological evidence from cross-sectional and long-term prospective studies and considers possible etiological mechanisms. Methods: Systematic reviews and methodologically robust studies in the field (from inception to February 2019) were identified using a comprehensive search of Medline, PsychINFO, and Embase and summarized using a narrative synthesis. Results: Consistent evidence, both from observational and experimental studies, has confirmed the important role of cannabis use in the initiation and persistence of psychotic disorders. The size of the effect is related to the extent of cannabis use, with greater risk for early cannabis use and use of high-potency varieties and synthetic cannabinoids. Accumulating evidence suggests that frequent cannabis use also increases the risk for mania as well as for suicide. However, the effect on depression is less clear and findings on anxiety are contradictory with only a few methodologically robust studies. Furthermore, the relationship with common mental disorders may involve reverse causality, as depression and anxiety are reported to lead to greater cannabis consumption in some studies. Pathogenetic mechanisms focus on the effect of tetrahydrocannabinol (THC, the main psychoactive ingredient of cannabis) interacting with genetic predisposition and perhaps other environmental risk factors. Cannabidiol (CBD), the other important ingredient of traditional cannabis, ameliorates the psychotogenic effects of THC but is absent from the high-potency varieties that are increasingly available. Conclusions: The evidence that heavy use of high-THC/low-CBD types of cannabis increases the risk of psychosis is sufficiently strong to merit public health education. Evidence of similar but smaller effects in mania and suicide is growing, but is not convincing for depression and anxiety. There is much current interest in the possibility that CBD may be therapeutically useful.

Psychosis-inducing effects of cannabis are related to both childhood abuse and COMT genotypes.

OBJECTIVE: To test whether the association between childhood abuse, cannabis use and psychotic experiences (PEs) was moderated by the COMT (catechol-O-methyltransferase) gene. METHOD: Psychotic experiences (PEs), childhood abuse, cannabis use and COMT Val158Met genotypes were assessed in 533 individuals from the general population. Data were analysed hierarchically by means of multiple linear regression models. RESULTS: Childhood abuse showed a significant main effect on both positive (ß = 0.09; SE = 0.04; P = 0.047) and negative PEs (ß = 0.11; SE = 0.05; P = 0.038). A significant three-way interaction effect was found among childhood abuse, cannabis use and the COMT gene on positive PEs (ß = -0.30; SE = 0.11; P = 0.006). This result suggests that COMT genotypes and cannabis use only influenced PE scores among individuals exposed to childhood abuse. Furthermore, exposure to childhood abuse and cannabis use increased PE scores in Val carriers. However, in individuals exposed to childhood abuse but who did not use cannabis, PEs increased as a function of the Met allele copies of the COMT gene. CONCLUSION: Cannabis use after exposure to childhood abuse may have opposite effects on the risk of PEs, depending on the COMT genotypes providing evidence for a qualitative interaction. Val carriers exposed to childhood abuse are vulnerable to the psychosis-inducing effects of cannabis.

Polymorphisms of COMT Val158Met and DAT1 3'-UTR VNTR in illicit drug use and drug-related psychiatric disorders.

To investigate the involvement of COMT Val158Met and DAT1 3'-UTR VNTR genotypes in the pathogenesis of illicit drug use and drug-induced psychotic disorders (DIP), 187 substance users and 386 normal controls were recruited from Northern Taiwan. Substance users and normal controls significantly differed in allele frequencies of COMT Val158Met (p = 0.039) but not in allele frequencies of DAT1 3'-UTR VNTR (p = 0.879). However, neither allele frequencies of COMT Val158Met nor allele frequencies of DAT1 3'-UTR VNTR were associated with DIP. The findings should be confirmed in further studies of a larger sample size and a more homogenous patient group.

Treatment of refractory substance-induced psychosis in adolescent males with a genetic predisposition to mental illness.

This article presents two cases of adolescent males who were admitted to our inpatient psychiatric unit with a psychotic, disorganized presentation. Both males had a genetic vulnerability to mental illness and reported significant substance use. Their symptoms were refractory to treatment and required the use of clozapine. Both patients experienced significant side effects, which limited the maximum daily dose of clozapine. However, they responded to a dose that was much lower than that typically used in adults. There is significant evidence in the literature about cannabis use triggering psychotic breaks in vulnerable individuals. We speculate that substance use (including synthetic cannabinoids) triggers treatment-resistant psychosis that requires the use of clozapine. Further, lower doses of clozapine may be sufficient to treat the substance-induced psychotic symptoms than those typically used in adult schizophrenia.

Comparison of history of adolescents with substance-induced psychosis, early onset schizophrenia and substance use disorders.

OBJECTIVE: The contribution contains a comparison of the history data of adolescent patients hospitalized at the Department of Child Psychiatry, Children´s Faculty Hospital in Bratislava with the diagnoses of Substance-Induced Psychosis (SIP), Early Onset Schizophrenia (EOS) and with Substance Use Disorders (SUD). BACKGROUND: SIP is rarely recorded and little documented by the age of 18. The etiology of this disorder is still relatively unclear. METHODS: The data collection was carried out from patients hospitalized between January 1, 2001 and December 31, 2012. We recorded data from 20 patients hospitalized with SIP, 50 patients hospitalized with EOS, and 50 patients hospitalized with SUD. We collected and compared the data on family history, perinatal complications, early psychomotor development, data on psychical problems before their hospitalization, and presence of unfavorable life situations in their childhood. CONCLUSION: The data of adolescents with SIP are more similar to the data of patients with EOS than patients with SUD in terms of the burden of family history, the frequency of complications during pregnancy and delivery, and the frequency of the subsequent early psychomotor impairment. In terms of unfavorable life situations and psychological problems for which they were monitored in a psychiatric ward before their hospitalization with SIP, their data are more similar to those of patients with SUD than with EOS (Tab. 3, Fig. 1, Ref. 21).

[Cannabis use and the risk of psychotic disorders. An update]. / Cannabis als risicofactor voor psychose: een update.

BACKGROUND: The use of cannabis has been linked to an increased risk for psychosis, irrespective of confounding factors such as age, gender, use of other drugs and reverse causality. Over the last few years a great deal of research has been done to broaden our understanding of the underlying mechanisms of this link. AIM: To update studies that have examined the link between cannabis use and psychosis and that have investigated the possible mechanisms underlying this link. METHOD: This article discusses recent epidemiological and experimental research that sheds light on the nature of the link and the influence of interactions between genes and environment. RESULTS: The long-term effects of cannabis on the risk factors for psychosis and psychotic disorders are influenced to a large extent by genetic and environmental factors. Furthermore, patients with a psychotic disorder seem to be extremely vulnerable to the acute effects of cannabis. CONCLUSION: Studies show that cannabis use is an important risk factor for psychosis and psychotic disorders. So far, however, less research has been done into the effects of cannabis use on patients already suffering from a psychotic disorder.

The NADPH oxidase NOX2 controls glutamate release: a novel mechanism involved in psychosis-like ketamine responses.

Subanesthetic doses of NMDA receptor antagonist ketamine induce schizophrenia-like symptoms in humans and behavioral changes in rodents. Subchronic administration of ketamine leads to loss of parvalbumin-positive interneurons through reactive oxygen species (ROS), generated by the NADPH oxidase NOX2. However, ketamine induces very rapid alterations, in both mice and humans. Thus, we have investigated the role of NOX2 in acute responses to subanesthetic doses of ketamine. In wild-type mice, ketamine caused rapid (30 min) behavioral alterations, release of neurotransmitters, and brain oxidative stress, whereas NOX2-deficient mice did not display such alterations. Decreased expression of the subunit 2A of the NMDA receptor after repetitive ketamine exposure was also precluded by NOX2 deficiency. However, neurotransmitter release and behavioral changes in response to amphetamine were not altered in NOX2-deficient mice. Our results suggest that NOX2 is a major source of ROS production in the prefrontal cortex controlling glutamate release and associated behavioral alterations after acute ketamine exposure. Prolonged NOX2-dependent glutamate release may lead to neuroadaptative downregulation of NMDA receptor subunits.

No significant association between SIRT1 gene and methamphetamine-induced psychosis in the Japanese population.

OBJECTIVES: We previously showed that the sirtuin 1 gene (SIRT1 gene), one of the clock genes, was associated with schizophrenia in a Japanese patient population. Because the symptoms of methamphetamine (METH)-induced psychosis are similar to those of paranoid type schizophrenia and because not every METH user develops psychosis, it is conceivable that METH-induced psychosis and schizophrenia have common susceptibility genes. Therefore, we conducted an analysis of the association of SIRT1 gene with METH-induced psychosis, hypothesizing a significant relationship. METHODS: This paper presents a case-control study of the SIRT1 gene in 515 Japanese individuals (197 with METH-induced psychosis and 318 age-matched and sex-matched controls) with four tagging single nucleotide polymorphisms (rs12778366, rs2273773, rs4746720, and rs10997875), selected a priori using the HapMap database. RESULTS: rs10997875 (located in the 3' flanking region) was associated with METH-induced psychosis (unadjusted p(genotype) = 0.0203). However, these results became non-significant after Bonferroni correction (corrected p(genotype) = 0.0812). In the all-marker haplotype analysis, the SIRT1 gene was not associated with METH-induced psychosis (p = 0.146). CONCLUSION: Our findings suggest that SIRT1 gene does not contribute to the development of METH-induced psychosis in the Japanese population. However, a replication study using larger samples should be conducted to obtain conclusive results.

The adenosine A2A receptor is associated with methamphetamine dependence/psychosis in the Japanese population.

BACKGROUND: Several lines of evidence suggest that the dopaminergic nervous system contributes to methamphetamine (METH) dependence, and there is increasing evidence of antagonistic interactions between dopamine and adenosine receptors. We therefore hypothesized that variations in the A2A adenosine receptor (ADORA2A) gene modify genetic susceptibility to METH dependence/psychosis. METHODS: We first analyzed variations in the exons and exon-intron boundaries of the ADORA2A gene in METH dependent/psychotic patients. Then an association analysis between these single nucleotide polymorphisms and METH dependence/psychosis was performed using a total of 171 METH dependent/psychotic patients and 229 controls. RESULTS: We found 6 variations, of which one single nucleotide polymorphism (SNP) was novel. Significant associations were observed between the allelic and genotypic frequencies of the Exon2+751 (rs5751876) SNP and METH dependence/psychosis. These associations were observed especially in females. In the clinical feature analyses, significant associations were observed between the SNP and the patient subgroup using METH alone (i.e., without concomitant use of other substances of abuse). CONCLUSIONS: These results suggest that the ADORA2A gene could be a vulnerability factor for METH dependence/psychosis, especially in females and/or in patients using only METH.

Update on marijuana.

Marijuana, the illicit drug most widely used by adolescents, is not a benign substance. Inhalation of marijuana smoke is more harmful than tobacco smoke; cannabis smoke delivers 50% to 70% more carcinogens. Other physiological effects include decreased immune function, higher rates of cardiac arrhythmias, and documented cases of cerebellar infarction. Mood and cognitive effects of marijuana include exacerbation of depression and anxiety (including panic attacks), as well as memory problems that may persist for a month after last use. Cannabis abuse is a risk factor for psychosis in genetically predisposed people and may lead to a worse outcome of schizophrenia. The cumulative respiratory, cardiovascular, metabolic, and mental health risks of marijuana are significant and should be emphasized by nurses who work with adolescents.

Genetic association studies of methamphetamine use disorders: A systematic review and synthesis.

Efforts to understand the biological processes that increase susceptibility to methamphetamine (METH) use disorders (i.e., abuse, dependence, and psychosis) have uncovered several putative genotypic variants. However, to date a synthesis of this information has not been conducted. Thus, systematic searches of the current literature were undertaken for genetic-association studies of METH use disorders. Each gene's chromosomal location, function, and examined polymorphic markers were extracted. Frequencies, odds ratios and 95% confidence intervals for risk alleles, as well as sample size and power, were calculated. We uncovered 38 studies examining 39 genes, of which 18 were found to have a significant genotypic, allelic, and/or haplotypic association with METH use disorders. Three genes (COMT, DRD4, and GABRA1) were associated with METH abuse, nine (ARRB2, BDNF, CYP2D6, GLYT1, GSTM1, GSTP1, PDYN, PICK1, and SLC22A3) with METH dependence, two (AKT1 and GABRG2) with METH abuse/dependence, and four (DTNBP1, OPRM1, SNCA, and SOD2) with METH psychosis. Limitations related to phenotypic classification, statistical power, and potential publication bias in the current literature were noted. Similar to other behavioral, psychiatric, and substance use disorders, the genetic epidemiology of METH use disorders is complex and likely polygenic. National and international collaborative efforts are needed to increase the availability of large population-based samples and improve upon the power to detect genetic associations of small magnitude. Further, replication of the findings reviewed here along with further development of more rigorous methodologies and reporting protocols will aid in delineating the complex genetic epidemiology of METH use disorders.

Antiepileptic drug-induced psychosis associated with MTHFR C677T: a case report.

BACKGROUND: Various antiepileptic drugs can potentially cause psychiatric side effects in patients with epilepsy, but the precise mechanism of these actions remains unknown. In recent years, the common polymorphism C677T in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene has attracted attention for its role in the onset of psychiatric diseases. MTHFR and several vitamins (as cofactors) are crucial for remethylation of homocysteine via folate and homocysteine metabolism. We report a case of a Japanese patient who presented with reversible schizophrenia-like symptoms during antiepileptic drug therapy. CASE PRESENTATION: Our patient had frontal lobe epilepsy and had been treated with several antiepileptic drugs since the age of 13 years. He developed auditory hallucinations and multiple personalities at 17 years of age, several months after the initiation of phenytoin and phenobarbital, despite these antiepileptic drugs being used within the therapeutic ranges. Genetic analysis revealed that he was homozygous for the C677T polymorphism of MTHFR. Hyperhomocysteinemia, hypomethionemia, and multiple vitamin deficiencies, including folate, riboflavin, and pyridoxal, were identified at the age of 23 years. Vitamin supplementation and alteration of the antiepileptic drugs improved his psychotic symptoms. Multiple vitamin deficiencies with homozygous MTHFR C677T should be considered in patients presenting with schizophrenia-like symptoms during antiepileptic drug therapy. CONCLUSIONS: To the best of our knowledge, this is the first report of antiepileptic drug-induced psychosis associated with homozygous C677T and multiple vitamin deficiencies. Our findings will contribute to the elucidation of the pathogenesis of the psychiatric side effects of antiepileptic drugs and lead to improved medical management for patients with epilepsy.

Trend level gene-gender interaction effect for the BDNF rs6265 variant on age of onset of psychosis.

A BDNF rs6265 [A/A] by gender by cannabis use interaction has been associated with age of onset of psychosis (AoP). We examined the gender and cannabis use-adjusted association between BDNF rs6265 [G>A] and AKT1 rs2494732 [T>C] and AoP. Data from 167 Caucasians on AoP and age at first regular cannabis use were collected. Kaplan-Meier and Cox regression analyses were conducted. A trend level gene-gender interaction effect was observed for the BDNF rs6265 A/A genotype, controlling for age at first regular cannabis use. Larger collaborative research projects are required to further investigate this effect.

Genetic Predisposition vs Individual-Specific Processes in the Association Between Psychotic-like Experiences and Cannabis Use.

Importance: Previous research indicates that cannabis use is associated with psychotic-like experiences (PLEs). However, it is unclear whether this association results from predispositional (ie, shared genetic) factors or individual-specific factors (eg, causal processes, such as cannabis use leading to PLEs). Objectives: To estimate genetic and environmental correlations between cannabis use and PLEs, and to examine PLEs in twin and nontwin sibling pairs discordant for exposure to cannabis use to disentangle predispositional from individual-specific effects. Design, Setting, and Participants: In this cross-sectional analysis, diagnostic interviews and self-reported data were collected from 2 separate population-based samples of twin and nontwin sibling pairs. Data from the Human Connectome Project were collected between August 10, 2012, and September 29, 2015, and data from the Australian Twin Registry Cohort 3 (ATR3) were collected between August 1, 2005, and August 31, 2010. Data were analyzed between August 17, 2017, and July 6, 2018. The study included data from 1188 Human Connectome Project participants and 3486 ATR3 participants, totaling 4674 participants. Main Outcomes and Measures: Three cannabis-involvement variables were examined: frequent use (ie, ≥100 times), a DSM-IV lifetime cannabis use disorder diagnosis, and current cannabis use. Genetic and environmental correlations between cannabis involvement and PLEs were estimated. Generalized linear mixed models examined PLE differences in twin and nontwin sibling pairs discordant for cannabis use. Results: Among the 4674 participants, the mean (SD) age was 30.5 (3.2) years, and 2923 (62.5%) were female. Data on race/ethnicity were not included as a covariate owing to lack of variability within the ATR3 sample; among the 1188 participants in the Human Connectome Project, 875 (73.7%) were white. Psychotic-like experiences were associated with frequent cannabis use (ß = 0.11; 95% CI, 0.08-0.14), cannabis use disorder (ß = 0.13; 95% CI, 0.09-0.16), and current cannabis use (ß = 0.07; 95% CI, 0.04-0.10) even after adjustment for covariates. Correlated genetic factors explained between 69.2% and 84.1% of this observed association. Within discordant pairs of twins/siblings (Npairs, 308-324), Psychotic-like experiences were more common in cannabis-exposed individuals compared with their relative who used cannabis to a lesser degree (ß ≥ .23, P < .05; eg, frequent and infrequent cannabis-using relatives significantly differed, z = -5.41; P < .001). Conclusions and Relevance: Despite the strong contribution of shared genetic factors, frequent and problem cannabis use also appears to be associated with PLEs via person-specific pathways. This study's findings suggest that policy discussions surrounding legalization should consider the influence of escalations in cannabis use on traitlike indices of vulnerability, such as PLEs, which could contribute to pervasive psychological and interpersonal burden.

Varenicline-induced mixed mood and psychotic episode in a patient with a past history of depression.

Varenicline is a promising agent with demonstrated efficacy in the promotion of smoking cessation. However, from the time of initial trials, it has been associated with significant psychiatric adverse effects. We describe a case where mixed mood and psychotic disturbance developed in an individual with a history of depression and a family history of bipolar disorder. Based on this case, we hypothesize a possible mechanism of action for these adverse effects and preventive measures that could be undertaken in its effective use.

The glycine transporter 1 gene (GLYT1) is associated with methamphetamine-use disorder.

Glycine transporter (GlyT)-1 plays a pivotal role in maintaining the glycine level at the glutamatergic synapse. Glycine is an allosteric agonist of N-methyl-D-aspartate (NMDA) receptors. Because activation of NMDA receptors is an essential step for induction of methamphetamine dependence and psychosis, differences in the functioning of GlyT-1 due to genetic variants of the GlyT-1 gene (GLYT1) may influence susceptibility. A case-control genetic association study of the GLYT1 gene examined 204 patients with methamphetamine-use disorder and 210 healthy controls. We examined three single nucleotide polymorphisms (SNPs), SNP1, IVS3 + 411C > T, rs2486001; SNP2, 1056G > A, rs2248829; and SNP3, IVS11 + 22G > A, rs2248632, of the GLYT1 gene and found that SNP1 showed a significant association in both genotype (P = 0.0086) and allele (P = 0.0019) with methamphetamine-use disorder. The T-G haplotype at SNP1 and SNP2 was a significant risk factor for the disorder (P = 0.000039, odds ratio: 2.04). The present findings indicate that genetic variation of the GLYT1 gene may contribute to individual vulnerability to methamphetamine dependence and psychosis.

[Potential genetic predictors for individual vulnerability to substance dependence].

Development of substance dependence is influenced by multiple factors, e.g. pharmacological effects on mental status, environmental and individual factors. Among them genetic factors were found to have greater affect on substance dependence than expected which inheritance rate was calculated as 0.7 or more. However, more precise information on genetic mechanisms underlying substance dependence is still unknown. In Japan, methamphetamine has been the most popular illicit drug. The JGIDA study for genetic factors of methamphetamine dependence/psychosis started in 2001, and revealed many potential genetic predictors for individual vulnerability to methamphetamine dependence and variation of clinical phenotypes. As to susceptibility to drug dependence, 17 genetic variants were identified. A certain SNP or haplotype of the DTNBP1, GSTM1, GSTP1, glycine transporter-1 gene produce risks and that of serotonin transporter, AKT1 and CYP2D6 gene produce negative risks. As to risks of rapid onset of methamphetamine psychosis, worse prognosis or complication of spontaneous relapse, the dopamine D2 receptors, dopamine transporter, monoamine oxidase-A, catechol-O-methyltransferese, SOD2, NQO2, PICK1 gene were identified. Odds ratios of these positive or negative risks ranged from about 0.2 to 15. These findings must be informative for drug dependence rehabilitation programs and psycho-education of substance dependence.

Gene variants and educational attainment in cannabis use: mediating role of DNA methylation.

Genetic and sociodemographic risk factors potentially associated with cannabis use (CU) were investigated in 40 cannabis users and 96 control subjects. DNA methylation analyses were also performed to explore the possibility of epigenetic changes related to CU. We conducted a candidate gene association study that included variants involved in the dopaminergic (ANKK1, NCAM1 genes) and endocannabinoid (CNR1, CNR2 gene) pathways. Sociodemographic data included gender, marital status, level of education, and body mass index. We used MeDIP-qPCR to test whether variations in DNA methylation might be associated with CU. We found a significant association between SNP rs1049353 of CNR1 gene (p = 0.01) and CU. Differences were also observed related to rs2501431 of CNR2 gene (p = 0.058). A higher education level appears to decrease the risk of CU. Interestingly, females were less likely to use cannabis than males. There was a significantly higher level of DNA methylation in cannabis users compared to controls in two of the genes tested: hypermethylation at exon 8 of DRD2 gene (p = 0.034) and at the CpG-rich region in the NCAM1 gene (p = 0.0004). Both genetic variants and educational attainment were also related to CU. The higher rate of DNA methylation, evidenced among cannabis users, may be either a marker of CU or a consequence of long-term exposure to cannabis. The identified genetic variants and the differentially methylated regions may represent biomarkers and/or potential targets for designs of pharmacological therapeutic agents. Our observations also suggest that educational programs may be useful strategies for CU prevention.