An association study between catechol-O-methyl transferase gene polymorphism and methamphetamine psychotic disorder

Associations between the COMT rs4680 Gene Polymorphism and Personality Dimensions and Anxiety in Patients with a Diagnosis of Other Stimulants Dependence

BACKGROUND

Research on the hypodopaminergic hypothesis of addictions showed that hypodopaminergic activity in males predicted the number of drugs used and is associated with drug-seeking behavior. Variant alleles may cause hypodopaminergic functioning as a result of the reduced density of dopamine receptors, decreased response to dopamine, increased dopamine clearance or metabolism in the reward system. The catechol-O-methyltransferase (COMT) is involved in the metabolism of dopamine. Personality traits may mediate the genetic predisposition to substance use disorders additively by various motivations associated with reward-seeking and regulating negative emotions, and also relate to self-control and environment selection.

THE AIM OF THE STUDY

The aim of this study was to investigate the association of the rs4680 polymorphism of COMT with personality dimensions and anxiety in patients addicted to stimulants other than cocaine (F15 according to WHO ICD-10 nomenclature) in the case of examined patients amphetamine.

METHODS

The study was conducted among patients addicted to stimulants other than cocaine (amphetamine). The study group included 247 patients addicted to stimulants (amphetamine) and the control group comprised 280 healthy male volunteers. The real-time PCR method was used to carry out genetic tests; personality dimensions were assessed using the standardized NEO-FFI and state and trait anxiety were assessed with STAI. All analyses were performed using STATISTICA 13.

RESULTS

The results of the 2 × 3 factorial ANOVA showed a statistically significant effect of the combined factor COMT rs4680 genotype on the group of patients diagnosed with other stimulants dependence/control (F_2,252 = 3.11, p = 0.0465, η² = 0.024). Additionally, we observed that the results of the 2 × 3 factorial ANOVA showed a statistically significant influence of the combined factor COMT rs4680 on the genotype in the group of patients diagnosis with other stimulants dependence/control (F_2,252 = 6.16, p = 0.0024, η² = 0.047).

CONCLUSIONS

In our research, the polymorphism G/G COMT rs4680 genotype was associated with higher scores of STAI traits and STAI states in the patients dependent on amphetamine. In the control group we observed no such interactions.

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.

Genetics of methamphetamine use disorder: A systematic review and meta-analyses of gene association studies

Genetic susceptibility to methamphetamine use disorder is poorly understood. No twin or adequately powered genome-wide association studies (GWASs) have been conducted. However, there are a large number of hypothesis-driven candidate gene association studies, which were systematically reviewed herein. Seventy-six studies were identified, investigating markers of 75 different genes. Allele frequencies, odds ratios, 95 % confidence intervals and power were calculated. Risk of bias was also assessed as a quality measure. Meta-analyses were conducted for gene markers if three or more studies were available. Eleven markers from adequately powered studies were significantly associated with methamphetamine use disorder, with Fatty Acid Amide Hydrolase (FAAH) and Brain Derived Neurotrophic Factor (BDNF) representing promising targets. Limitations of these studies include unclear rationale for candidate gene selection, low power and high risk of bias. Future research should include replications to enable more meta-analyses, well-powered GWASs or whole exome or genome sequencing, as well as twin and family studies to further complement the findings of this review to uncover genetic contributions toward methamphetamine use disorder.

A Review of Risk Factors for Methamphetamine-Related Psychiatric Symptoms

The illegal use of methamphetamine (MA) is a growing public health concern globally and results in a series of negative effects. The prominent detrimental effect of MA use is MA-related psychiatric symptoms (MAP) and is observed at a much higher incidence compared to the general population. MAP often includes multiple dimensions of cognitive impairment and induces adverse consequences such as, violence and suicide. However, the assessment methods for MAP are not standardized. Hence, it is necessary to investigate factors that affect the progression of psychiatric symptoms in individuals who use MA. A review of published studies was performed by searching the following databases: PubMed, EMBASE, and PsycINFO from inception to 31 May, 2018. The search strategy included methamphetamine, dependence, psychiatric symptoms, and risk factor terms. We reviewed the different features of MAP and the various types of assessment instruments and summarized MAP risk factors from MA use-related factors, socio-demographic characteristics, life events, and genetic factors. We found that MAP was consistently and causally associated with MA use, particularly as it relates to the frequency and amount of MA use. Other MAP-related risk factors like life events and genetics were relatively inconsistent in their association with MAP. Hence, causal and longitudinal studies that focus on multilateral comparisons are required. This review provides high quality evidence for MAP risk factors and would be helpful for developing early prevention and treatment strategies for MAP.

Identification of Treatment Targets in a Genetic Mouse Model of Voluntary Methamphetamine Drinking

Methamphetamine has powerful stimulant and euphoric effects that are experienced as rewarding and encourage use. Methamphetamine addiction is associated with debilitating illnesses, destroyed relationships, child neglect, violence, and crime; but after many years of research, broadly effective medications have not been identified. Individual differences that may impact not only risk for developing a methamphetamine use disorder but also affect treatment response have not been fully considered. Human studies have identified candidate genes that may be relevant, but lack of control over drug history, the common use or coabuse of multiple addictive drugs, and restrictions on the types of data that can be collected in humans are barriers to progress. To overcome some of these issues, a genetic animal model comprised of lines of mice selectively bred for high and low voluntary methamphetamine intake was developed to identify risk and protective alleles for methamphetamine consumption, and identify therapeutic targets. The mu opioid receptor gene was supported as a target for genes within a top-ranked transcription factor network associated with level of methamphetamine intake. In addition, mice that consume high levels of methamphetamine were found to possess a nonfunctional form of the trace amine-associated receptor 1 (TAAR1). The Taar1 gene is within a mouse chromosome 10 quantitative trait locus for methamphetamine consumption, and TAAR1 function determines sensitivity to aversive effects of methamphetamine that may curb intake. The genes, gene interaction partners, and protein products identified in this genetic mouse model represent treatment target candidates for methamphetamine addiction.

Animal models of gene-environment interaction in schizophrenia: A dimensional perspective

Schizophrenia has long been considered as a disorder with multifactorial origins. Recent discoveries have advanced our understanding of the genetic architecture of the disease. However, even with the increase of identified risk variants, heritability estimates suggest an important contribution of non-genetic factors. Various environmental risk factors have been proposed to play a role in the etiopathogenesis of schizophrenia. These include season of birth, maternal infections, obstetric complications, adverse events at early childhood, and drug abuse. Despite the progress in identification of genetic and environmental risk factors, we still have a limited understanding of the mechanisms whereby gene-environment interactions (G × E) operate in schizophrenia and psychoses at large. In this review we provide a critical analysis of current animal models of G × E relevant to psychotic disorders and propose that dimensional perspective will advance our understanding of the complex mechanisms of these disorders.

Predictors of methamphetamine psychosis: history of ADHD-relevant childhood behaviors and drug exposure

The goal of this study was to extend our previous research that reported a significant association between Attention Deficit Hyperactivity Disorder (ADHD)-relevant childhood behaviors and the frequency of methamphetamine (MA)-induced psychotic symptoms in an expanded sample. 190 participants who met DSM-IV criteria for MA dependence were administered the Methamphetamine Experience Questionnaire that assessed MA-induced psychosis. Data related to MA exposure, comorbid drug use, education, familial psychiatric history and assessments of ADHD-relevant childhood behaviors as measured by the Wender Utah Rating Scale (WURS) were collected. Although WURS scores did not differ between 145 MAP+ and 45 MAP- subjects, MAP+ subjects with higher WURS scores were significantly more likely to report more frequent psychosis. Although mean daily MA dosage did not differ between the MAP+ and MAP- subjects, MAP+ subjects who consumed larger doses of MA were significantly more likely to experience frequent psychosis. These data suggest that ADHD-relevant childhood behaviors may interact with MA exposure to reflect a neurobiological vulnerability related to the emergence of frequent MA-induced psychotic symptoms. These results may elucidate factors that contribute to the psychiatric sequelae of MA abuse.

Drugs of abuse and increased risk of psychosis development

OBJECTIVE

There is considerable evidence to suggest that the abuse of illicit drugs, particularly cannabis and methamphetamine, has aetiological roles in the pathogenesis of psychosis and schizophrenia. Factors that may increase susceptibility to the propsychotic effects of these drugs include the age at which the abuse starts as well as family history of genetic polymorphisms relevant to the pathophysiology of this disorder. However, the neurobiological mechanisms involved in drug abuse-associated psychosis remain largely unclear.

METHODS AND RESULTS

This paper presents an overview of the available evidence, including clinical, animal model, and molecular studies, with a focus on brain regions and neurotransmitters systems, such as dopamine and glutamate, previously implicated in psychosis.

CONCLUSION

It is clear that further studies are urgently needed to provide a greater insight into the mechanisms that mediate the long-term and neurodevelopmental effects of cannabis and methamphetamine. A dialogue between basic science and clinical research may help to identify at-risk individuals and novel pathways for treatment and prevention.

Genetic factors modulating the response to stimulant drugs in humans

Individuals vary in their responses to stimulant drugs, and several lines of evidence suggest that the basis for this variation is at least partially genetic in origin. Association studies have examined the effects of polymorphisms in specific genes on acute and chronic responses to stimulant drugs. Several of these genetic polymorphisms are also associated with other psychiatric dimensions and disorders.This chapter examines the evidence for genetic associations between the genes that have been most carefully examined for their influence on the response to stimulant drugs.

Methamphetamine-associated psychosis

Methamphetamine (METH) is a frequent drug of abuse in U.S. populations and commonly associated with psychosis. This may be a factor in frequent criminal justice referrals and lengthy treatment required by METH users. Persecutory delusions and auditory hallucinations are the most consistent symptoms of METH-associated psychosis (MAP). MAP has largely been studied in Asian populations and risk factors have varied across studies. Duration, frequency and amount of use as well as sexual abuse, family history, other substance use, and co-occurring personality and mood disorders are risk factors for MAP. MAP may be unique with its long duration of psychosis and recurrence without relapse to METH. Seven candidate genes have been identified that may be associated with MAP. Six of these genes are also associated with susceptibility, symptoms, or treatment of schizophrenia and most are linked to glutamatergic neurotransmission. Animal studies of pre-pulse inhibition, attenuation of social interaction, and stereotypy and alterations in locomotion are used to study MAP in rodents. Employing various models, rodent studies have identified neuroanatomical and neurochemical changes associated with METH use. Throughout this review, we identify key gaps in our understanding of MAP and suggest potential directions for future research.

Presynaptic regulation of dopamine transmission in schizophrenia

A role for dopamine (DA) release in the hallucinations and other positive symptoms associated with schizophrenia has long been inferred from the antipsychotic response to D2 DA receptor antagonists and because the DA releaser amphetamine can be psychotogenic. Recent studies suggest that patients with schizophrenia, including those never exposed to antipsychotic drugs, maintain high presynaptic DA accumulation in the striatum. New laboratory approaches are elucidating mechanisms that control the level of presynaptic DA stores, thus contributing to fundamental understanding of the basic pathophysiologic mechanism in schizophrenia.

Methamphetamine use parameters do not predict neuropsychological impairment in currently abstinent dependent adults

Methamphetamine (meth) abuse is increasingly of public health concern and has been associated with neurocognitive dysfunction. Some previous studies have been hampered by background differences between meth users and comparison subjects, as well as unknown HIV and hepatitis C (HCV) status, which can also affect brain functioning. We compared the neurocognitive functioning of 54 meth dependent (METH+) study participants who had been abstinent for an average of 129 days, to that of 46 demographically comparable control subjects (METH-) with similar level of education and reading ability. All participants were free of HIV and HCV infection. The METH+ group exhibited higher rates of neuropsychological impairment in most areas tested. Among meth users, neuropsychologically normal (n=32) and impaired (n=22) subjects did not differ with respect to self-reported age at first use, total years of use, route of consumption, or length of abstinence. Those with motor impairment had significantly greater meth use in the past year, but impairment in cognitive domains was unrelated to meth exposure. The apparent lack of correspondence between substance use parameters and cognitive impairment suggests the need for further study of individual differences in vulnerability to the neurotoxic effects of methamphetamine.

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.

Pharmacogenetic treatments for drug addiction: cocaine, amphetamine and methamphetamine

BACKGROUND

Pharmacogenetics uses genetic variation to predict individual differences in response to medications and holds much promise to improve treatment of addictive disorders.

OBJECTIVES

To review how genetic variation affects responses to cocaine, amphetamine, and methamphetamine and how this information may guide pharmacotherapy.

METHODS

We performed a cross-referenced literature search on pharmacogenetics, cocaine, amphetamine, and methamphetamine.

RESULTS

We describe functional genetic variants for enzymes dopamine-beta-hydroxylase (DbetaH), catechol-O-methyltransferase (COMT), and dopamine transporter (DAT1), dopamine D4 receptor, and brain-derived neurotrophic factor (BDNF). A single nucleotide polymorphism (SNP; C-1021T) in the DbetaH gene is relevant to paranoia associated with disulfiram pharmacotherapy for cocaine addiction. Individuals with variable number tandem repeats (VNTR) of the SLC6A3 gene 3'-untranslated region polymorphism of DAT1 have altered responses to drugs. The 10/10 repeat respond poorly to methylphenidate pharmacotherapy and the 9/9 DAT1 variant show blunted euphoria and physiological response to amphetamine. COMT, D4 receptor, and BDNF polymorphisms are linked to methamphetamine abuse and psychosis.

CONCLUSIONS

Disulfiram and methylphenidate pharmacotherapies for cocaine addiction are optimized by considering polymorphisms affecting DbetaH and DAT1 respectively. Altered subjective effects for amphetamine in DAT1 VNTR variants suggest a 'protected' phenotype.

SCIENTIFIC SIGNIFICANCE

Pharmacogenetic-based treatments for psychostimulant addiction are critical for successful treatment.

An association study of monoamine oxidase A (MAOA) gene polymorphism in methamphetamine psychosis

Methamphetamine continues to be the most widely abused drug in Japan. Chronic methamphetamine users show psychiatric signs, including methamphetamine psychosis. Monoamine oxidase A (MAOA) is one of the major enzymes responsible for the degradation of neurotransmitters. Abnormalities in MAO levels have been related to a wide range of psychiatric disorders. We examined whether or not the MAOA-u variable-number tandem repeat (VNTR) has a functional polymorphism in methamphetamine psychosis and whether or not such a polymorphism is related to the prolongation of psychosis. As expected, there was a significant difference in the MAOA-u VNTR between males with persistent versus transient methamphetamine psychosis (p=0.018, odds ratio (OR)=2.76, 95% CI: 1.18-6.46). Our results suggest that the high-activity allele class of MAOA-u VNTR in males may be involved in susceptibility to a persistent course of methamphetamine psychosis. We found no differences among females. The sample size of females with methamphetamine psychosis was too small to have significant analysis.

Potential adverse effects of amphetamine treatment on brain and behavior: a review

Amphetamine stimulants have been used medically since early in the twentieth century, but they have a high abuse potential and can be neurotoxic. Although they have long been used effectively to treat attention deficit hyperactivity disorder (ADHD) in children and adolescents, amphetamines are now being prescribed increasingly as maintenance therapy for ADHD and narcolepsy in adults, considerably extending the period of potential exposure. Effects of prolonged stimulant treatment have not been fully explored, and understanding such effects is a research priority. Because the pharmacokinetics of amphetamines differ between children and adults, reevaluation of the potential for adverse effects of chronic treatment of adults is essential. Despite information on the effects of stimulants in laboratory animals, profound species differences in susceptibility to stimulant-induced neurotoxicity underscore the need for systematic studies of prolonged human exposure. Early amphetamine treatment has been linked to slowing in height and weight growth in some children. Because the number of prescriptions for amphetamines has increased several fold over the past decade, an amphetamine-containing formulation is the most commonly prescribed stimulant in North America, and it is noteworthy that amphetamines are also the most abused prescription medications. Although early treatment does not increase risk for substance abuse, few studies have tracked the compliance and usage profiles of individuals who began amphetamine treatment as adults. Overall, there is concern about risk for slowed growth in young patients who are dosed continuously, and for substance abuse in patients first medicated in late adolescence or adulthood. Although most adult patients also use amphetamines effectively and safely, occasional case reports indicate that prescription use can produce marked psychological adverse events, including stimulant-induced psychosis. Assessments of central toxicity and adverse psychological effects during late adulthood and senescence of adults who receive prolonged courses of amphetamine treatment are warranted. Finally, identification of the biological factors that confer risk and those that offer protection is also needed to better specify the parameters of safe, long-term, therapeutic administration of amphetamines to adults.

Short allele of 5-HTTLPR as a risk factor for the development of psychosis in Japanese methamphetamine abusers

Accumulating evidence suggests that genetic factors contribute to the vulnerability to methamphetamine (MAP) abuse and associated psychiatric symptoms. Chronic MAP abuse leads to psychosis, which may be of a transient or a prolonged type. Serotonergic dysfunction has been proposed as one of the contributory factors in the development of MAP psychosis. Our PET studies revealed that the serotonin transporter (5-HTT) density in global brain regions is significantly lower in MAP abusers. In this study, we examined the role of a functional polymorphism in the 5' flanking region of the 5-HTT gene (5-HTTLPR) in the development of MAP psychosis in a Japanese population. We analyzed DNA samples from 166 MAP patients (95 with transient and 71 with prolonged psychosis) and 197 age-, sex-, and geographic-origin-matched healthy controls. Patients were also subdivided according to the presence (n= 119) or absence (n= 148) of spontaneous relapse. We observed significant genotypic association of the 5-HTTLPR polymorphism with MAP psychosis (P= 0.022), particularly in patients who show prolonged psychosis. The frequency of the S allele in patients with prolonged psychosis was significantly higher than that of the controls (P= 0.045); it was further higher in patients with prolonged psychosis with spontaneous relapse (P= 0.004). 5-HTTLPR has been suggested to regulate the transcriptional activity of 5-HTT, with S alleles showing lesser transcriptional efficiency and also lower 5-HT(1A) receptor-binding potential. Prolonged MAP use, combined with the high frequency of 5-HTTLPR S-alleles, may lead to reduced 5-HTT levels and 5-HT(1A) receptor-binding potential in the brain, resulting in the dysfunction of the serotonergic system. Thus, we suggest a possible role for the 5-HTTLPR polymorphism in MAP psychosis.

Association between the catechol-O-methyltransferase Val158Met polymorphism and cocaine dependence

Dopaminergic brain systems have been documented to have a major role in drug reward, thus making genes involved in these circuits plausible candidates for susceptibility to substance use disorders. The catechol-O-methyltransferase (COMT) is involved in the degradation of catecholamines and a functional polymorphism (Val158Met) has been suggested to influence enzyme activity. In this study we hypothesize that genetic variation in the COMT gene contributes to increased risk for cocaine dependence. Cocaine-dependent individuals (n=330) and screened unaffected normal controls (n=255) were genotyped for three SNPs in the COMT gene (rs737865, rs4680 (Val158Met), rs165599). All cases and controls were of African descent. Genotype and allele frequencies differed significantly for the Val158Met polymorphism between cases (f(Met)=35%) and controls (f(Met)=27%) (p=0.004; corrected p=0.014; OR 1.44; 95% CI 1.12-1.86). Haplotype analysis showed a significant association for a two-marker haplotype rs737865-Val158Met (p=0.005). Results suggest that variation in COMT increases risk for cocaine dependence. The low enzyme activity 158Met allele or haplotypes containing this variant might have functional effects on dopamine-derived reward processes and cortical functions resulting in increased susceptibility for cocaine dependence. Additional studies are required to elucidate the role of COMT in the pathophysiology of substance use disorders.

Evidence that the COMTVal158Met Polymorphism Moderates Subclinical Psychotic and Affective Symptoms in Unaffected First-Degree Relatives of Patients With Schizophrenia

Objectives.

Psychotic patients with COMTVal158Met Met alleles were recently found to display more intense psychotic and affective responses to daily life stressors. We aimed to test the hypothesis that the Met allele is implicated in the development of affective and psychotic symptomatology in subjects genetically at risk for schizophrenia, by testing if unaffected first-degree relatives of patients with schizophrenia who share a Met allele have greater concordance of symptomatology than relatives not sharing a Met allele.

Methods.

Unaffected relatives (n = 38) were arranged in as many genetically related pairs as possible (n = 26), and Met-sharing between Index Unaffected Subject (IUS) and Related Unaffected Subject (RUS) was assessed. Symptomatology was assessed with the Brief Psychiatric Rating Scale (BPRS) total score.

Results.

Multilevel regression revealed an interaction between RUS BPRS score and Met-sharing in the model of IUS BPRS score (interaction χ2 = 3.78, p = 0.05). Stratified analyses revealed that IUS–RUS total BPRS scores were significantly associated in the case of Met-sharing (B = 0.57, 95% CI: 0.22–0.93, p = 0.002), but were not when there was no Met-sharing.

Conclusion.

These findings support the hypothesis that the Met allele may be involved in the causation of psychopathology, at least in populations with a genetic predisposition to psychosis.

Preliminary evidence of behavioral predictors of recurrent drug-induced psychosis in methamphetamine abuse

The goal of this study was to examine behavioral characteristics of currently drug-abstinent methamphetamine (MA)-dependent subjects (n=39) who experienced psychotic symptoms associated with MA abuse. All participants completed the Wender Utah Rating Scale (WURS), which retrospectively assesses Attention Deficit Hyperactivity Disorder-relevant childhood behaviors. The results suggest the existence of possible behavioral markers reflecting an early cognitive vulnerability to the development of frequent MA-induced psychotic symptoms as well as increased vulnerability associated with a family history of psychiatric illness.