The neurobiology of methamphetamine induced psychosis

Far-infrared Ray-mediated Antioxidant Potentials are Important for Attenuating Psychotoxic Disorders

Far-infrared ray (FIR) is an electromagnetic wave that produces various health benefits against pathophysiological conditions, such as diabetes mellitus, renocardiovascular disorders, stress, and depression etc. However, the therapeutic ap-plication on the FIR-mediated protective potentials remains to be further extended. To achieve better understanding on FIR-mediated therapeutic potentials, we summarized additional findings in the present study that exposure to FIR ameliorates stressful condition, memory impairments, drug dependence, and mitochondrial dysfunction in the central nervous system. In this review, we underlined that FIR requires modulations of janus kinase 2 / signal transducer and activator of transcription 3 (JAK2/STAT3), nuclear factor E2-related factor 2 (Nrf-2), muscarinic M1 acetylcholine receptor (M1 mAChR), dopamine D1 receptor, protein kinase C δ gene, and glutathione peroxidase-1 gene for exerting the protective potentials in response to neuropsychotoxic conditions

A prior history of binge-drinking increases sensitivity to the motivational valence of methamphetamine in female C57BL/6J mice

Methamphetamine (MA) and alcohol use disorders exhibit a high degree of co-morbidity and sequential alcohol-MA mixing increases risk for co-abuse. Recently, we reported greater MA-conditioned reward in male C57BL/6J mice with a prior history of binge alcohol-drinking (14 days of 2-hour access to 5, 10, 20 and 40% alcohol). As female mice tend to binge-drink more alcohol than males and females tend to be more sensitive than males to the psychomotor-activating properties of MA, we first characterized the effects of binge-drinking upon MA-induced place-conditioning (four pairings of 0.25, 0.5, 1, 2, or 4 mg/kg IP) in females and then incorporated our prior data to analyze for sex differences in MA-conditioned reward. Prior binge-drinking history did not significantly affect locomotor hyperactivity or its sensitization in female mice. However, the dose-response function for place-conditioning was shifted to the left of water-drinking controls, indicating an increase in sensitivity to MA-conditioned reward. The examination of sex differences revealed no sex differences in alcohol intake, although females exhibited greater MA-induced locomotor stimulation than males, irrespective of their prior drinking history. No statistically significant sex difference was apparent for the potentiation of MA-conditioned reward produced by prior binge-drinking history. If relevant to humans, these data argue that both males and females with a prior binge-drinking history are similarly vulnerable to MA abuse and it remains to be determined whether or not the neural substrates underpinning this increased vulnerability reflect common or sex-specific adaptations in reward-related brain regions.

The Relationship Between Serum Cytokine Levels and the Degree of Psychosis and Cognitive Impairment in Patients With Methamphetamine-Associated Psychosis in Chinese Patients

Background: Cytokine levels can be changed in methamphetamine (METH) use disorders (MUDs) and primary psychosis. The present study assessed serum levels of some kinds of interleukins (ILs) in METH-associated psychosis (MAP) and their relationships with psychotic symptoms and cognitive dysfunction. Methods: Serum IL-2R, IL-6, IL-8, and IL-10 levels were examined by chemiluminescence assays in MAP patients (n = 119) and healthy controls (n = 108). The Positive and Negative Syndrome Scale (PANSS) and Montreal Cognitive Assessment (MOCA) were administered. Results: Serum levels of IL-6 and IL-8 were significantly increased in MAP patients (all p < 0.05). There was a negative relationship between IL-2R levels and PANSS positive (P) subscale scores (r = -0.193, p = 0.035). IL-6, IL-8 and IL-10 levels were all negatively correlated with the naming, delayed recall and orientation subscores on the MOCA (r = -0.209, p = 0.022; r = -0.245, p = 0.007; r = -0.505, p < 0.001, respectively). Conclusions: Our results indicate that immune disturbances are related to MAP and that IL-2R, IL-6, IL-8, and IL-10 are associated with the severity of psychotic symptoms and cognitive function impairment.

Neuronal and peripheral damages induced by synthetic psychoactive substances: an update of recent findings from human and animal studies

Preclinical and clinical studies indicate that synthetic psychoactive substances, in addition to having abuse potential, may elicit toxic effects of varying severity at the peripheral and central levels. Nowadays, toxicity induced by synthetic psychoactive substances poses a serious harm for health, since recreational use of these substances is on the rise among young and adult people. The present review summarizes recent findings on the peripheral and central toxicity elicited by “old” and “new” synthetic psychoactive substances in humans and experimental animals, focusing on amphetamine derivatives, hallucinogen and dissociative drugs and synthetic cannabinoids.

Factors affecting the occurrence of psychotic symptoms in chronic methamphetamine users

Studies of risk for psychotic symptoms in methamphetamine users have focused primarily on drug use immediately before symptoms had appeared. Here we assessed factors reflecting characteristics of lifetime methamphetamine use before the appearance of psychotic symptoms. Four hundred ninety-five methamphetamine users (322 men, 173 women) were studied with consideration of the following features of methamphetamine use: age of initiation, maximum single dose, number of uses at or near the maximum dose, longest period of daily use, average dosage during that period, number of heavy use periods, and number of sustained abstinence periods (>1 month). Use of drugs other than methamphetamine and family history of schizophrenia were also considered. Retrospective self-reports of psychotic symptoms were obtained on the Brief Psychiatric Rating Scale. Factors associated with the occurrence of initial psychotic symptom(s) were identified using logistic regression. Later age of initiation, more uses at maximal or near maximal dosage, and more periods of prolonged abstinence were identified as protective factors. We conclude that early methamphetamine use can promote psychotic symptoms, possibly by altering neurodevelopment, whereas long abstinence periods may protect by allowing recovery. Negative associations of the appearance of psychotic symptom(s) with frequent high-dose administration suggest protection through tolerance.

Structural, functional, and neurochemical neuroimaging of methamphetamine-associated psychosis: A systematic review

Methamphetamine is a highly addictive psychostimulant. A subset of methamphetamine users develops methamphetamine-associated psychosis (MAP), which causes poorer prognoses and cognitive function than those with no psychosis (MNP). Comprehensive and integrative summaries of studies utilizing various neuroimaging modalities (structural, functional, and neurochemical) are limited. We conducted a systematic review of literature regarding clinical neuroimaging research published between January 1988 and July 2018 using the PubMed, Web of Science, Scopus, and ScienceDirect databases. Studies comparing the neuroimaging of patients with MAP with healthy controls or patients with MNP or schizophrenia were included to understand the distinct profiles associated with MAP. A total of six structural, three functional, and three neurochemical studies were reviewed. A general trend was identified that showed MAP-related brain alterations were mainly in the frontal lobe (especially the orbitofrontal cortex), striatum, and limbic systems (amygdala and hippocampus). Furthermore, some clinical manifestations, such as the severity of psychotic symptoms and cognitive performance, were correlated with neuroimaging abnormalities. In summary, distinct structural, functional, and neurochemical changes, especially in the frontostriatal circuit and network dynamic systems, play critical roles in the pathophysiology of MAP. Future studies using longitudinal study designs and including individuals with MNP and schizophrenia as controls are warranted.

Methamphetamine-associated psychosis: Clinical presentation, biological basis, and treatment options

INTRODUCTION

Methamphetamine associated psychosis (MAP) represents a mental disorder induced by chronic methamphetamine use in a subset of users. The prevalence of the disorder has increased in several countries in Europe and Asia where methamphetamine use has increased. MAP remains difficult to distinguish from primary psychiatric disorders, especially schizophrenia, creating complications in prescribing treatment plans to patients.

DESIGN

This narrative review sought to summarize difficulties related to MAP diagnosis and highlight the need for a better treatment model. Current best practices are described and potential novel therapies and future research suggested.

RESULTS

Results suggest that clear biological and clinical differences appear between patients presenting with MAP and schizophrenia and that there may exist distinct subgroups within MAP itself. MAP-specific treatment studies have been few and have focused on the use of antipsychotic medication. Antipsychotic treatment has been shown to alleviate the psychotic symptoms of MAP but produce debilitating adverse effects and fail to adequately address methamphetamine use in patients.

CONCLUSIONS

Continued identification of subgroups within the heterogenous MAP population may lead to better diagnosis, treatment, and outcomes for patients. Psychosocial therapies should be explored in addressing the cooccurring substance use and psychosis in the treatment of MAP.

Identification of cytotoxic markers in methamphetamine treated rat C6 astroglia-like cells

Methamphetamine (METH) is a powerfully addictive psychostimulant that has a pronounced effect on the central nervous system (CNS). The present study aimed to assess METH toxicity in differentiated C6 astroglia-like cells through biochemical and toxicity markers with acute (1 h) and chronic (48 h) treatments. In the absence of external stimulants, cellular differentiation of neuronal morphology was achieved through reduced serum (2.5%) in the medium. The cells displayed branched neurite-like processes with extensive intercellular connections. Results indicated that acute METH treatment neither altered the cell morphology nor killed the cells, which echoed with lack of consequence on reactive oxygen species (ROS), nitric oxide (NO) or inhibition of any cell cycle phases except induction of cytoplasmic vacuoles. On the other hand, chronic treatment at 1 mM or above destroyed the neurite-like processors and decreased the cell viability that paralleled with increased levels of ROS, lipid peroxidation and lactate, depletion in glutathione (GSH) level and inhibition at G0/G1 phase of cell cycle, leading to apoptosis. Pre-treatment of cells with N-acetyl cysteine (NAC, 2.5 mM for 1 h) followed by METH co-treatment for 48 h rescued the cells completely from toxicity by decreasing ROS through increased GSH. Our results provide evidence that increased ROS and GSH depletion underlie the cytotoxic effects of METH in the cells. Since loss in neurite connections and intracellular changes can lead to psychiatric illnesses in drug users, the evidence that we show in our study suggests that these are also contributing factors for psychiatric-illnesses in METH addicts.

Paranoid schizophrenia and methamphetamine-induced paranoia are both characterized by a similar LINE-1 partial methylation profile, which is more pronounced in paranoid schizophrenia

BACKGROUND

There is evidence that schizophrenia is a neuro-immune disorder. Genes linked to intragenic LINE-1 methylation show a strong association with immune-associated disorders including psychosis. The aim of this study was to examine LINE-1 methylation patterns in paranoid schizophrenia and methamphetamine-induced paranoia, a model for schizophrenia.

METHODS

This study recruited 31 patients with paranoid schizophrenia, 94 with methamphetamine-induced paranoia (MIP) and 163 normal controls. LINE-1 methylation patterns were assayed in peripheral blood mononuclear cells and a combined bisulphite restriction analysis and COBRA were used to estimate LINE1 methylation (mC) and CpG dinucleotide methylation patterns, namely 2 methylated (mCmC) and 2 unmethylated (uCuC) CpGs and the partially methylated loci mCuC (5'm with 3'u) and uCmC (5'u with 3'm).

RESULTS

Patients with paranoid schizophrenia show highly significant changes in LINE-1 partial methylation patterns, namely a higher percentage of mCuC and lower percentage of uCmC as compared with controls and MIP patients, while the latter show a higher percentage of mCuC but lower percentage of uCmC as compared with controls. Higher mCuC significantly predicts paranoid schizophrenia with a sensitivity of 51.6%, specificity of 97.5% and an area under the ROC curve of 0.895.

CONCLUSIONS

The results indicate that a common dysfunction in LINE-1 partial methylation may underpin both paranoid schizophrenia and MIP and that this methylation pattern is significantly more expressed in paranoid schizophrenia than MIP. Reciprocal links between impairments in LINE-1 methylation and neuro-immune and neuro-oxidative pathways may underpin the pathophysiology of both MIP and paranoid schizophrenia.

Involvement of C/EBPβ-related signaling pathway in methamphetamine-induced neuronal autophagy and apoptosis

Methamphetamine (METH) is a widely abused illicit psychoactive drug. Our previous study has shown that CCAAT-enhancer binding protein β (C/EBPβ) is an important regulator in METH-induced neuronal autophagy and apoptosis. However, the detailed molecular mechanisms underlying this process remain poorly understood. Previous studies have demonstrated that DNA damage-inducible transcript 4 (DDIT4), Trib3 (tribbles pseudo kinase 3), alpha-synuclein (α-syn) are involved in METH-induced dopaminergic neurotoxicity. We hypothesized that C/EBPβ is involved in METH-induced DDIT4-mediated neuronal autophagy and Trib3-mediated neuronal apoptosis. We tested our hypothesis by examining the effects of silencing C/EBPβ, DDIT4, Trib3 or α-syn with small interfering ribonucleic acid (siRNA) on METH-induced autophagy and apoptosis in the human neuroblastoma SH-SY5Y cells. We also measured the levels of phosphorylated tuberous sclerosis complex 2 (TSC2) protein and Parkin protein level in SH-SY5Y cells. Furthermore, we demonstrated the effect of silencing C/EBPβ on METH-caused neurotoxicity in the striatum of rats by injecting LV-shC/EBPβ lentivirus using a stereotaxic positioning system. The results showed that METH exposure increased C/EBPβ, DDIT4 protein expression. Elevated DDIT4 expression raised up p-TSC2/TSC2 protein expression ratio, inhibited mTOR signaling pathway, activating cell autophagy. We also found that METH exposure increased the expression of Trib3, α-syn, decreased the Parkin protein expression. Lowering levels of Parkin raised up α-syn expression, which initiated mitochondrial apoptosis by down-regulating anti-apoptotic Bcl-2, followed by up-regulation of pro-apoptotic Bax, resulting in translocation of cytochrome c (cyto c), an apoptogenic factor, from the mitochondria to cytoplasm and activation of caspase-dependent pathways. These findings were supported by data showing METH-induced autophagy and apoptosis was significantly inhibited by silencing C/EBPβ, DDIT4, Trib3 or α-syn, or by Parkin over-expression. Based on the present data, a novel of mechanism on METH-induced cell toxicity is proposed, METH exposure increased C/EBPβ protein expression, triggered DDIT4/TSC2/mTOR signaling pathway, and evoked Trib3/Parkin/α-syn-related mitochondrial apoptotic signaling pathway. Collectively, these results suggest that C/EBPβ plays an important role in METH-triggered autophagy and apoptosis and it may be a potential target for therapeutics in METH-caused neurotoxicity.

A Case Study of Acute Stimulant-induced Psychosis

Psychosis resulting from stimulant overuse is commonly observed in clinical practices today. This is in large part due to the significant increase in attention-deficit/hyperactive disorder (ADHD) diagnoses in recent years, the increase in methamphetamine trafficking, and the prevalence of stimulant use in the day-to-day activities by many of those living in today’s fast-paced society. The current inability to predict those users who will experience stimulant-induced psychosis from those users who will not needs further investigation.

In this case study, we examine why one particular stimulant user experiences stimulant-induced psychosis. We give an account of a patient with an acute psychotic episode admitted to the emergency room at a local hospital. During initial evaluation, it was discovered that he had been diagnosed with ADHD one month ago and that the onset of his symptoms was likely related to an overuse of amphetamines. The patient had no personal history or family history of any psychiatric or mood disorders. He had no history of recreational drug use prior to this incident, and had no history of seizures or head trauma. After appropriate pharmacological intervention with antipsychotics and psychological intervention, the patient showed gradual improvement over the next five days of his hospitalization. After the five days, he was allowed to be discharged.

We conclude with the cautionary advice that a patient’s susceptibility of experiencing stimulant-induced psychosis should be assessed before prescribing stimulants. In cases where stimulant use is not supervised by a physician, appropriate understanding of management of stimulant-induced psychosis is of utmost importance in order to provide the very best patient education and care.

Antipsychotics for Amphetamine Psychosis. A Systematic Review

Background: Among individuals experiencing amphetamine psychosis, it may be difficult to rule out schizophrenia. The use of antipsychotics for the treatment of amphetamine psychosis is sparse due to possible side effects. Some arguments disfavor their use, stating that the psychotic episode is self-limited. Without treatment, some individuals may not fully recover from the psychosis and may develop full-blown psychosis, emotional, and cognitive disturbance. This review aims to investigate the clinical benefits and risks of antipsychotics for the treatment of amphetamine psychosis. Methods: Electronic search on trials on antipsychotic drugs for amphetamine psychosis from their inception to November 2018 was conducted in PubMed, Scopus, Google Scholar, EBSCOhost, ProQuest, Cochrane Review Database, Medline Ovid, and EMBASE following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The Cochrane risk-of-bias tool assessed the risk of bias, the methodological quality of individual trials was assessed by the Oxford Quality Scoring System, and the quality of evidence for recommendations was judged by the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE). The results were synthesized qualitatively and quantitatively. Results: The investigation of six randomized controlled trials of 314 participants showed that aripiprazole, haloperidol, quetiapine, olanzapine, and risperidone were able to reduce or control the psychotic episode (positive and negative symptoms) induced by amphetamine use with no adverse event. Although the side-effect profile of these agents varied, no drug was clinically superior to others. Conclusions: This review suggests that antipsychotics seem to be efficacious for amphetamine psychosis on both positive and negative symptoms. Practitioners need to tailor their use based on risks for side effects individually.

Variants in GABBR1 Gene Are Associated with Methamphetamine Dependence and Two Years' Relapse after Drug Rehabilitation

Methamphetamine (MA) use disorder is a growing global health challenge marked by a steady increase worldwide. GABAergic system plays an important role in the mechanism of drug dependence, however few studies about the association between methamphetamine use disorder and genes in GABAergic system. Concerning GABBR1 gene which encoding the GABAB receptor subunit 1 is an important regulator in the GABAergic system. The aim of the study is to explore whether GABBR1 gene play a role in methamphetamine dependence and relapse after rehabilitation. Three single nucleotide polymorphisms (SNPs, rs2076483, rs29221, rs715044) of the GABBR1 gene were genotyped in 791 participants with MA use disorder and 448 healthy controls. The distribution of genotypes and alleles of the three SNPs between the two groups and their subgroups (dependence and abuse) was been analyzed. The multivariate logistic model was used to identify factors associate with relapse of MA use disorder during the following 2 years after drug rehabilitation. It was found that the C allele frequency of rs715044 of the GABBR1 gene was associated with MA use disorder and MA dependence. The CGA (rs2076483- rs29221- rs715044) was negatively associated with MA use disorder. The drug use years and rs29221 GG genotype were associated with relapse during the following 2 years after drug rehabilitation. GABBR1 gene may be associated with the susceptibility for MA use disorder and relapse and it indicates that the GABAergic system may play a role in the MA use disorder. Graphical Abstract GABBR1 gene may be associated with the susceptibility for MA use disorder and relapse and it indicates that the GABAergic system may play a role in the MA use disorder.

Gaps in the ice: Methamphetamine in Australia; its history, treatment, and ramifications for users and their families

It is now well-established that Australia has a significant issue with methamphetamine. Recent dramatic changes in manufacturing have led to significant shifts in both the patterns of use and the relative purity of this illicit drug, with the crystalline form of methamphetamine commonly referred to as 'ice'. Excessive use not only impacts on those taking the drug, but also takes a heavy toll on their families. With few effective treatment options currently available, there is a strong focus on developing replacement pharmacotherapies and examining the efficacy of outpatient counselling and residential treatment options. Recent research in addiction care supports the positive impact that families of users can have on both treatment and recovery for their loved ones. Despite this recognition, there is little current research looking at the experiences of families of users of the uniquely problematic drug methamphetamine. This paper outlines the historical narrative that has led to the current worldwide phenomenon of ice use and explores contemporary directions of research into its impact and potential treatments. In doing so, it outlines the relatively unexplored impact of ice on families and highlights a current need for nursing research into their experiences living with loved ones using the drug.

Association Between Delusions of Infestation and Prescribed Narcotic and Stimulant Use

OBJECTIVE

Patients diagnosed with delusions of infestation (DOI) at a psychodermatology clinic appeared to have a higher incidence of being prescribed narcotic or stimulant medications compared with the general dermatologic clinic population with chronic pruritic conditions. A retrospective study was conducted examining the correlation between patients with DOI and prescribed psychoactive medications.

METHODS

Ninety-two patients with a diagnosis of DOI, seen at our University Psychodermatology Clinic, served as the study population. The comparison group (N=354) included dermatology patients seen at a dermatology clinic by the same dermatologist for itching, including adults seen for chronic pruritic conditions and contact dermatitis. For both groups, the reported use of any psychoactive prescription medications was noted.

RESULTS

Patients with DOI were significantly more likely than other dermatology patients to receive prescriptions for narcotics [adjusted odds ratio (OR)=2.19; confidence interval (CI)=1.21-3.99) and stimulants (OR=5.44; CI=2.37-12.52). Patients with DOI were also more likely to be female (OR=2.49; CI=1.47-4.22) than patients who did not have such delusions.

DISCUSSION

Few data are available concerning the etiology and management of DOI. Findings from this study indicated an association between the diagnosis of DOI and the prescribing of narcotics and stimulants, even when sex and age were taken into account. This information may be used to assist with the diagnosis of patients presenting with DOI and possible treatment options. It will be important to determine if these medications are a cause of the condition, or are merely correlated with other medical conditions.

Relationship between schizophrenia and changes in the expression of the long non-coding RNAs Meg3, Miat, Neat1 and Neat2

Schizophrenia (SZ) is a complex disease caused by multiple factors. The development of the disease is mediated by a number of neural growth and development factors, suggesting that extensive changes in nerve structure and abnormal expression of genes in some important signalling pathways occur. Based on accumulating evidence, long non-coding RNAs (lncRNAs) play a crucial role in regulating neural diseases, including SZ. In the current study, we used mouse models of methamphetamine (METH) - and MK801-induced SZ to investigate changes in the expression of four lncRNAs (Meg3, Miat, Neat1 and Neat2) in the prefrontal cortex (PFC). Miat and Neat2 expression was significantly decreased in the PFC of the SZ model mice, regardless of whether the disease was induced by MK801 or METH. We further measured the levels of these lncRNAs in the peripheral blood (PB) collected from treated and untreated patients with SZ and from healthy controls. Neat1 and Neat2 levels were significantly decreased in the PB of untreated patients with SZ, but the trends in the expression of these lncRNAs nearly reached a normal level in treated patients with SZ. In conclusion, Neat2 and Miat may function as important regulators of SZ. Our findings provide important clues for new targets of lncRNAs that are involved in SZ.

Methamphetamine dependence with and without psychotic symptoms: A multi-modal brain imaging study

OBJECTIVE

Methamphetamine dependence can lead to psychotic symptoms which may be mediated by frontal, striatal, limbic, and thalamic regions. There are few neuroimaging data that allow comparison of individuals with methamphetamine dependence who do, and do not, have psychosis. Two complementary imaging techniques were employed to investigate neurocircuitry associated with methamphetamine dependence with and without psychotic symptoms.

METHODS

Three groups of participants were recruited: methamphetamine dependent (MAA) (N = 11), methamphetamine dependent with psychotic symptoms (MAP) (N = 14), and controls (N = 14). Resting brain glucose metabolism was measured using [¹⁸F]fluorodeoxyglucose (FDG) positron emission tomography (PET) and cerebral perfusion was assessed using arterial spin labelling (ASL) magnetic resonance imaging.

RESULTS

Methamphetamine abusers (MAA and MAP groups) had decreased glucose metabolism compared to healthy controls in the left insula, left precentral gyrus, and the anterior cingulate cortex. Compared to MAA participants, MAP participants had 1) decreased glucose metabolism in the left precentral gyrus and the left inferior frontal gyrus and 2) increased glucose metabolism in the putamen and pallidum. MAP participants also had increased cerebral perfusion in the right putamen and right pallidum compared to MAA.

CONCLUSION

Findings support the involvement of frontal, striatal, and limbic regions in methamphetamine dependence. Furthermore, they indicate that glucose metabolism and cerebral perfusion in these regions are disrupted in methamphetamine dependent individuals with psychotic symptoms.

Methamphetamine (MA) Use Induces Specific Changes in LINE-1 Partial Methylation Patterns, Which Are Associated with MA-Induced Paranoia: a Multivariate and Neuronal Network Study

The use of psychoactive substances, including methamphetamine (MA) may cause changes in DNA methylation. The aim of this study was to examine the effects of MA use on long interspersed element-1 (LINE-1) methylation patterns in association with MA-induced paranoia. This study recruited 123 normal controls and 974 MA users, 302 with and 672 without MA-induced paranoia. The Semi-Structured Assessment for Drug Dependence and Alcoholism was used to assess demographic and substance use variables. Patterns of LINE-1 methylation were assessed in peripheral blood mononuclear cells and a combined bisulfite restriction analysis (COBRA) was used to estimate overall LINE-1 methylation (mC) while COBRA classified LINE-alleles into four patterns based on the methylation status of two CpG dinucleotides on each strand from 5' to 3', namely two methylated (mCmC) and two unmethylated (uCuC) CpGs and two types of partially methylated loci (mCuC that is 5'm with 3'u and uCmC that is 5'u with 3'm CpGs). MA users showed higher % mCuC and % mCuC + uCmC levels than controls. Use of solvents and opioids, but not cannabis and alcohol dependence, significantly lowered % uCmC levels, while current smoking significantly increased % uCuC levels. MA-induced paranoia was strongly associated with changes in LINE-1 partial methylation patterns (lowered % uCmC), heavy MA use, lower age at onset of MA use, and alcohol dependence. Women who took contraceptives showed significantly lower LINE-1 % mC and % mCmC and higher % uCuC levels than women without contraceptive use and men. The results show that MA-induced changes in LINE-1 partial methylation patterns are associated with MA-induced paranoia and could explain in part the pathophysiology of this type of psychosis. It is argued that MA-induced neuro-oxidative pathways may have altered LINE-1 partial methylation patterns, which in turn may regulate neuro-oxidative and immune pathways, which may increase risk to develop MA-induced paranoia.

Genetic and animal model analyses reveal the pathogenic role of a novel deletion of RELN in schizophrenia

Reelin protein (RELN), an extracellular matrix protein, plays multiple roles that range from embryonic neuronal migration to spine formation in the adult brain. Results from genetic studies have suggested that RELN is associated with the risk of psychiatric disorders, including schizophrenia (SCZ). We previously identified a novel exonic deletion of RELN in a patient with SCZ. High-resolution copy number variation analysis revealed that this deletion included exons 52 to 58, which truncated the RELN in a similar manner to the Reln Orleans mutation (Reln^rl-Orl). We examined the clinical features of this patient and confirmed a decreased serum level of RELN. To elucidate the pathophysiological role of the exonic deletion of RELN in SCZ, we conducted behavioral and neurochemical analyses using heterozygous Reln^rl-Orl/+ mice. These mice exhibited abnormalities in anxiety, social behavior, and motor learning; the deficits in motor learning were ameliorated by antipsychotics. Methamphetamine-induced hyperactivity and dopamine release were significantly reduced in the Reln^rl-Orl/+ mice. In addition, the levels of GABAergic markers were decreased in the brain of these mice. Taken together, our results suggest that the exonic deletion of RELN plays a pathological role, implicating functional changes in the dopaminergic and GABAergic systems, in the pathophysiology of SCZ.

The Main Molecular Mechanisms Underlying Methamphetamine- Induced Neurotoxicity and Implications for Pharmacological Treatment

Methamphetamine (METH) is a popular new-type psychostimulant drug with complicated neurotoxicity. In spite of mounting evidence on METH-induced damage of neural cell, the accurate mechanism of toxic effect of the drug on central nervous system (CNS) has not yet been completely deciphered. Besides, effective treatment strategies toward METH neurotoxicity remain scarce and more efficacious drugs are to be developed. In this review, we summarize cellular and molecular bases that might contribute to METH-elicited neurotoxicity, which mainly include oxidative stress, excitotoxicity, and neuroinflammation. We also discuss some drugs that protect neural cells suffering from METH-induced neurotoxic consequences. We hope more in-depth investigations of exact details that how METH produces toxicity in CNS could be carried out in future and the development of new drugs as natural compounds and immunotherapies, including clinic trials, are expected.

The sigma-1 receptor as a regulator of dopamine neurotransmission: A potential therapeutic target for methamphetamine addiction

Methamphetamine (METH) abuse is a major public health issue around the world, yet there are currently no effective pharmacotherapies for the treatment of METH addiction. METH is a potent psychostimulant that increases extracellular dopamine levels by targeting the dopamine transporter (DAT) and alters neuronal activity in the reward centers of the brain. One promising therapeutic target for the treatment of METH addiction is the sigma-1 receptor (σ1R). The σ1R is an endoplasmic reticulum-localized chaperone protein that is activated by cellular stress, and, unique to this chaperone, its function can also be induced or inhibited by different ligands. Upon activation of this unique "chaperone receptor", the σ1R regulates a variety of cellular functions and possesses neuroprotective activity in the brain. Interestingly, a variety of σ1R ligands modulate dopamine neurotransmission and reduce the behavioral effects of METH in animal models of addictive behavior, suggesting that the σ1R may be a viable therapeutic target for the treatment of METH addiction. In this review, we provide background on METH and the σ1R as well as a literature review regarding the role of σ1Rs in modulating both dopamine neurotransmission and the effects of METH. We aim to highlight the complexities of σ1R pharmacology and function as well as the therapeutic potential of the σ1R as a target for the treatment of METH addiction.

Behavioral and Serotonergic Changes in the Frontal Cortex Following Methamphetamine Self-Administration

BACKGROUND

Methamphetamine use is associated with a variety of negative health outcomes, including psychosis. The frontal cortex serotonin receptors are thought to contribute to psychosis-like behaviors. This study investigated changes in serotonergic markers in the frontal cortex following methamphetamine self-administration and hallucinogenic drug-induced behavior.

METHODS

Consistent with previously published studies, freely cycling male and female rats were allowed to self-administer methamphetamine (males: 0.12 mg/infusion; females: 0.09 mg/infusion) or saline (10 µL) for 7 days. On the day following self-administration or following 10 days of extinction training, animals were given the serotonin 2A/2C agonist, 1-(2,5-Dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (2 mg/kg, i.p.), and head twitches were analyzed. Autoradiography was also used to assess serotonin receptors and transporters in the frontal cortex following self-administration.

RESULTS

Methamphetamine self-administration led to an increase in DOI-induced head-twitch behavior compared to saline only on the day following self-administration. Increases in serotonin receptors in the orbitofrontal cortex and decreases in serotonin transporters in the orbitofrontal cortex and infralimbic cortex were observed following methamphetamine self-administration as assessed by autoradiography.

CONCLUSIONS

Methamphetamine self-administration was associated with serotonergic alterations in the frontal cortex, which may underlie behavioral changes related to methamphetamine-associated psychosis.

Genetic variation of GRIA3 gene is associated with vulnerability to methamphetamine dependence and its associated psychosis

Methamphetamine (METH) is an addictive psychostimulant drug commonly leading to schizophrenia-like psychotic symptoms. Disturbances in glutamatergic neurotransmission have been proposed as neurobiological mechanisms and the α-amino-3 hydroxy-5 methyl-4 isoxazole propionic acid (AMPA) glutamate receptor has been implicated in these processes. Moreover, genetic variants in GRIAs, genes encoding AMPA receptor subunits, have been observed in association with both drug dependence and psychosis. We hypothesized that variation of GRIA genes may be associated with METH dependence and METH-induced psychosis. Genotyping of GRIA1 rs1428920, GRIA2 rs3813296, GRIA3 rs3761554, rs502434 and rs989638 was performed in 102 male Thai controls and 100 METH-dependent subjects (53 with METH-dependent psychosis). We observed no evidence of association with METH dependence and METH-dependent psychosis in the GRIA1 and GRIA2 polymorphisms, nor with single polymorphisms rs3761554 and rs989638 in GRIA3. An association of GRIA3 rs502434 was identified with both METH dependence and METH-dependent psychosis, although this did not withstand correction for multiple testing. Combining the analysis of this site with the previously-demonstrated association with BDNF rs6265 resulted in a highly significant effect. These preliminary findings indicate that genetic variability in GRIA3 may interact with a functional BDNF polymorphism to provide a strong risk factor for the development of METH dependence in the Thai population.

Olanzapine and haloperidol for the treatment of acute symptoms of mental disorders induced by amphetamine-type stimulants: A randomized controlled trial

BACKGROUND

This study aimed to compare olanzapine and haloperidol efficacies in the treatment of acute psychiatric symptoms due to amphetamine-type stimulants (ATSs).

METHODS

The Zelen II design method was used; 124 patients with acute mental disorders due to amphetamine were randomly divided into olanzapine group (n = 63) and haloperidol group (n = 61). Then, a 4-week open-label medical therapy was performed. Clinical Global Impression Scale Item 2 was employed to evaluate the onset time; meanwhile, Brief Psychiatric Rating Scale (BPRS) was used at baseline and at posttreatment weeks 1, 2, and 4. Moreover, adverse reactions during the treatment were recorded.

RESULTS

Onset time in the olanzapine group was significantly earlier than in the haloperidol group; BPRS scores in the olanzapine group were significantly lower than haloperidol group values at 1 and 2 weeks of treatment. The overall effective rates had no statistically significant difference.

CONCLUSION

Short-term olanzapine and haloperidol treatments had equivalent efficacies in the treatment of acute symptoms of mental disorders due to ATSs; however, olanzapine administration resulted in relatively earlier disease onset, with less adverse reactions.

A Research of Methamphetamine Induced Psychosis in 1,430 Individuals With Methamphetamine Use Disorder: Clinical Features and Possible Risk Factors

Background and Aims: Methamphetamine (MA) abuse is commonly associated with the development of psychotic symptoms. The predictors and related risk factors of MA induced psychosis (MIP) are poorly understood. We investigated the occurrence of MIP, and analyzed the clinical features and possible risk factors among individuals with MA use disorder Method: One thousand four hundred and thirty participants with MA use disorder were recruited from compulsory rehabilitation centers in Shanghai. A structured questionnaire including demographic characteristics, drug use history, visual analog scales, Beck Depression Inventory-13 (BDI-13), and Hamilton anxiety scale-14 (HAMA-14) were used to collect clinical related information. Fifty-six participants had accomplished the test of CogState Battery. Results: Among the 1430 individuals with MA use disorder, 37.1% were diagnosed as MIP according DSM-IV. There were significant differences in age, marital status, age of drug use onset, MA use years, Average MA use dose, interval of MA use, maximum dose, concurrent use of alcohol, and other drugs, VAS score, MA dependence, BDI-13 scores, HAMA-14 scores, verbal learning memory, and visual learning memory between the MIP group and the none MIP group (P < 0.05). The age of drug use onset (OR = 0.978, p = 0.011), average drug use dose (OR = 1.800, p = 0.015), craving score (OR = 1.069, p = 0.031), MA dependence (OR = 2.214, p < 0.001), and HAMA scores (OR = 1.028, p < 0.001) were associated to MIP. Conclusion: Individuals with MIP had more severe drug use problems, emotional symptoms and cognitive impairment. Earlier onset of drug use, higher quantity of drug use, higher craving, middle or severe drug use disorder and more anxiety symptoms may be related risk factors of MIP.

Distinct intrinsic functional brain network abnormalities in methamphetamine-dependent patients with and without a history of psychosis

Chronic methamphetamine use is associated with executive functioning deficits that suggest dysfunctional cognitive control networks (CCNs) in the brain. Likewise, abnormal connectivity between intrinsic CCNs and default mode networks (DMNs) has also been associated with poor cognitive function in clinical populations. Accordingly, we tested the extent to which methamphetamine use predicts abnormal connectivity between these networks, and whether, as predicted, these abnormalities are compounded in patients with a history of methamphetamine-associated psychosis (MAP). Resting-state fMRI data were acquired from 46 methamphetamine-dependent patients [19 with MAP, 27 without (MD)], as well as 26 healthy controls (CTRL). Multivariate network modelling and whole-brain voxel-wise connectivity analyses were conducted to identify group differences in intrinsic connectivity across four cognitive control and three DMN networks identified using an independent components analysis approach (meta-ICA). The relationship of network connectivity and psychotic symptom severity, as well as antipsychotic treatment and methamphetamine use variables, was also investigated. Robust evidence of hyper-connectivity was observed between the right frontoparietal and anterior DMN networks in MAP patients, and 'normalized' with increased duration of treatment with antipsychotics. Attenuation of anticorrelated anterior DMN-dorsal attention network activity was also restricted to this group. Elevated coupling detected in MD participants between anterior and posterior DMN networks became less apparent with increasing duration of abstinence from methamphetamine. In summary, we observed both alterations of RSN connectivity between DMN networks with chronic methamphetamine exposure, as well as DMN-CCN coupling abnormalities consistent with possible MAP-specific frontoparietal deficits in the biasing of task-appropriate network activity.

MicroRNA expression signature of methamphetamine use and addiction in the rat nucleus accumbens

Methamphetamine (METH) is a highly addictive psycho-stimulant that induces behavioral changes due to high level of METH-induced dopamine in the brain. Nucleus accumbens (NAc) plays an important role in these changes, especially in drug addiction. However, little is known about the underlying molecular mechanisms of METH-induced addiction. The objective of this study was to establish a behavioral model of METH use and addiction using escalating doses of METH over 15 days and to determine the global miRNA expression profiling in NAc of METH-addicted rats. In the behavioral study, the experimental rats were divided into 3 groups of 9 each: a control group, a single dose METH (5 mg/kg) treatment group and a continuous 15 alternate days METH (0.25, 0.5, 1, 2, 3, 4, 5 mg/kg) treatment group. Following that, six rats in each group were randomly selected for global miRNA profiling. Addiction behavior in rats was established using Conditioned Place Preference task. The analysis of the miRNA profiling in the NAc was performed using Affymetric microarray GeneChip® System. The findings indicated that a continuous 15 alternate days METH treatment rats showed a preference for the drug-paired compartment of the CPP. However, a one-time acute treatment with 5 mg/kg METH did not show any significant difference in preference when compared with controls. Differential profiling of miRNAs indicated that 166 miRNAs were up-regulated and 4 down-regulated in the chronic METH-treatment group when compared to controls. In comparing the chronic treatment group with the acute treatment group, 52 miRNAs were shown to be up-regulated and 7 were down-regulated. MiRNAs including miR-496-3p, miR-194-5p, miR-200b-3p and miR-181a-5p, were found to be significantly associated with METH addiction. Canonical pathway analysis revealed that a high number of METH addiction-related miRNAs play important roles in the MAPK, CREB, G-Protein Couple Receptor and GnRH Signaling pathways. Our results suggest that dynamic changes occur in the expression of miRNAs following METH exposure and addiction.

Can the symptoms of schizophrenia be reset?

This work basing on a study of medical records is a story of a young patient, repeatedly hospitalized with various diagnoses, in whom the psychiatric symptoms significantly decreased after waking from coma, resulting from an unfortunate accident.

There are presented subsequent stages of treatment and hospitalizations and the analysis of the problem if the restart is possible in terms of mental state, in a patient who for years had experienced omental-delusive experiences of high severity and anxiety, leading to several suicidal attempts with serious consequences.

The discussion also describes the issue of double diagnosis and the criteria for amphetamine-induced psychosis.

Can schizophrenia be cured and its symptoms reset ?

Molecular, Behavioral, and Physiological Consequences of Methamphetamine Neurotoxicity: Implications for Treatment

Understanding the relationship between the molecular mechanisms underlying neurotoxicity of high-dose methamphetamine (METH) and related clinical manifestations is imperative for providing more effective treatments for human METH users. This article provides an overview of clinical manifestations of METH neurotoxicity to the central nervous system and neurobiology underlying the consequences of administration of neurotoxic METH doses, and discusses implications of METH neurotoxicity for treatment of human abusers of the drug.

Characterization of white matter integrity deficits in cocaine-dependent individuals with substance-induced psychosis compared with non-psychotic cocaine users

With sufficient drug exposure, some individuals develop transient psychotic symptoms referred to as 'substance-induced psychosis' (SIP), which closely resemble the symptoms observed in schizophrenia spectrum disorders. The comparability in psychotic presentation between SIP and the schizophrenias suggests that similar underlying neural deficits may contribute to the emergence of psychosis across these disorders. Only a small number of studies have investigated structural alterations in SIP, and all have been limited to volumetric imaging methods, with none controlling for the effects of chronic drug exposure. To investigate white matter abnormalities associated with SIP, diffusion tensor imaging was employed in a group of individuals with cocaine-associated psychosis (CAP; n = 24) and a cocaine-dependent non-psychotic (CDN) group (n = 43). Tract-based spatial statistics was used to investigate group differences in white matter diffusion parameters. The CAP group showed significantly lower fractional anisotropy values than the CDN group (p < 0.05) in voxels within white matter tracts of fronto-temporal, fronto-thalamic and interhemispheric pathways. The greatest differences in white matter integrity were present in the corpus callosum, corona radiata, bilateral superior longitudinal fasciculi and bilateral inferior longitudinal fasciculi. Additionally, the CAP group had voxels of significantly higher radial diffusivity in a subset of the previously mentioned pathways. These results are the first description of white matter integrity abnormalities in a SIP sample and indicate that differences in these pathways may be a shared factor in the expression of different forms of psychosis.

Parallel changes in serum proteins and diffusion tensor imaging in methamphetamine-associated psychosis

Methamphetamine-associated psychosis (MAP) involves widespread neurocognitive and molecular deficits, however accurate diagnosis remains challenging. Integrating relationships between biological markers, brain imaging and clinical parameters may provide an improved mechanistic understanding of MAP, that could in turn drive the development of better diagnostics and treatment approaches. We applied selected reaction monitoring (SRM)-based proteomics, profiling 43 proteins in serum previously implicated in the etiology of major psychiatric disorders, and integrated these data with diffusion tensor imaging (DTI) and psychometric measurements from patients diagnosed with MAP (N = 12), methamphetamine dependence without psychosis (MA; N = 14) and healthy controls (N = 16). Protein analysis identified changes in APOC2 and APOH, which differed significantly in MAP compared to MA and controls. DTI analysis indicated widespread increases in mean diffusivity and radial diffusivity delineating extensive loss of white matter integrity and axon demyelination in MAP. Upon integration, several co-linear relationships between serum proteins and DTI measures reported in healthy controls were disrupted in MA and MAP groups; these involved areas of the brain critical for memory and social emotional processing. These findings suggest that serum proteomics and DTI are sensitive measures for detecting pathophysiological changes in MAP and describe a potential diagnostic fingerprint of the disorder.

Drug Abuse and Psychosis: New Insights into Drug-induced Psychosis

Addictive drug use or prescribed medicine abuse can cause psychosis. Some representative symptoms frequently elicited by patients with psychosis are hallucination, anhedonia, and disrupted executive functions. These psychoses are categorized into three classifications of symptoms: positive, negative, and cognitive. The symptoms of DIP are not different from the symptoms of schizophrenia, and it is difficult to distinguish between them. Due to this ambiguity of distinction between the DIP and schizophrenia, the DIP animal model has been frequently used as the schizophrenia animal model. However, although the symptoms may be the same, its causes are clearly different in that DIP is acquired and schizophrenia is heritable. Therefore, in this review, we cover several DIP models such as of amphetamine, PCP/ketamine, scopolamine, and LSD, and then we also address three schizophrenia models through a genetic approach with a new perspective that distinguishes DIP from schizophrenia.

Subcortical grey matter alterations in cocaine dependent individuals with substance-induced psychosis compared to non-psychotic cocaine users

After prolonged psychostimulant abuse, transient psychotic symptoms referred to as "substance-induced psychosis" (SIP) can develop - closely resembling symptoms observed in schizophrenia spectrum disorders. The comparability in psychotic presentation between SIP and schizophrenias suggests that similar underlying neural deficits may contribute to the expression of psychosis across these disorders. To date, neuroanatomical characterization of grey matter structural alterations in SIP has been limited to methamphetamine associated psychosis, with no studies controlling for potential neurotoxic effects of the psychostimulant that precipitates psychosis. To investigate grey matter subcortical alterations in SIP, a voxel-based analysis of magnetic resonance images (MRI) was performed between a group of 74 cocaine dependent nonpsychotic individuals and a group of 29 individuals with cocaine-associated psychosis. The cocaine-associated psychosis group had significantly smaller volumes of the thalamus and left hippocampus, controlling for age, total brain volume, current methamphetamine dependence, and current marijuana dependence. No differences were present in bilateral caudate structures. The findings of reduced thalamic and hippocampal volumes agree with previous reports in the schizophrenia literature, suggesting alterations of these structures are not specific to schizophrenia, but may be common to multiple forms of psychosis.

Inhibitory effect of melatonin on cerebral endothelial cells dysfunction induced by methamphetamine via NADPH oxidase-2

Melatonin is a hormone that mostly produced from the pineal gland, and it performs as a strong neuroprotectant to both neuron and glial cells against methamphetamine (METH)-induced neurotoxicity. Recently, it has been found that METH also damages the blood brain barrier (BBB) structure and function. However, the protective mechanism of melatonin on the BBB impairment caused by METH has not been investigated. In this study, the primary rat brain microvascular endothelium cells (BMVECs) isolated from neonatal rats was used to investigate the protective effect of melatonin on METH-induced BBB impairment and the underlying mechanism. The results demonstrated that melatonin decreased the level of reactive oxygen species (ROS), reactive nitrogen species (RNS), and apoptosis induced by METH via NADPH oxidase (NOX)-2 since apocynin, a NOX-2 inhibitor abolished those changes. In addition, melatonin was found to improve cell integrity by increasing the transendothelial electric resistance (TEER) values, and up-regulate the tight junction proteins ZO-1, occludin, and claudin-5, thereby decreasing the paracellular permeability caused by METH mediated by NOX-2. Our data suggest that METH induces BBB impairment by mediating NOX-2 activity, and then induces oxidative and nitrative stress, as well as apoptosis, which causes the impairment of cell integrity, and that melatonin reduces these negative effects of METH by mediating via MT1/2 receptors.

Astrocytic and neuronal localization of kynurenine aminotransferase-2 in the adult mouse brain

During catabolism of tryptophan through the kynurenine (KYN) pathway, several endogenous metabolites with neuromodulatory properties are produced, of which kynurenic acid (KYNA) is one of the highest significance. The causal role of altered KYNA production has been described in several neurodegenerative and neuropsychiatric disorders (e.g., Parkinson's disease, Huntington's disease, schizophrenia) and therefore kynurenergic manipulation with the aim of therapy has recently been proposed. Conventionally, KYNA is produced from its precursor L-KYN with the aid of the astrocytic kynurenine aminotransferase-2 (KAT-2) in the murine brain. Although the mouse is a standard therapeutic research organism, the presence of KAT-2 in mice has not been described in detail. This study demonstrates the presence of kat-2 mRNA and protein throughout the adult C57Bl6 mouse brain. In addition to the former expression data from the rat, we found prominent KAT-2 expression not only in the astrocyte, but also in neurons in several brain regions (e.g., hippocampus, substantia nigra, striatum, and prefrontal cortex). A significant number of the KAT-2 positive neurons were positive for GAD67; the presence of the KAT-2 enzyme we could also demonstrate in mice brain homogenate and in cells overexpressing recombinant mouse KAT-2 protein. This new finding attributes a new role to interneuron-derived KYNA in neuronal network operation. Furthermore, our results suggest that the thorough investigation of the spatio-temporal expression pattern of the relevant enzymes of the KYN pathway is a prerequisite for developing and understanding the pharmacological and transgenic murine models of kynurenergic manipulation.

Psychosis induced by amphetamines

PURPOSE OF REVIEW

The study reviews publications on the use of methamphetamine and amphetamine in relation to psychotic symptoms, substance-induced psychosis, and primary psychosis published between July 2014 and December 2015. The databases MEDLINE, Embase, and PsycINFO were searched using the terms 'amphetamine psychosis' and 'methamphetamine psychosis' for the time period 1 July 2014 to 31 December 2015.

RECENT FINDINGS

There were 37 studies published on the subject during this time period. Risk factors for psychotic symptoms, substance-induced psychosis, and primary psychosis included patterns of drug use, but results also pointed to the importance of nondrug-related vulnerability. Cognitive impairment is associated with both amphetamine use and psychosis, and the impairment among those with amphetamine-induced psychosis resembles that of schizophrenia. At the neuronal level, GABAergic mechanisms may offer some understanding about the association between stimulant use and psychosis. Several different types of antipsychotic medication are effective for treating agitation and psychosis, but drugs with high DRD2 blockade should be used with caution. Some novel treatments are described, but are not sufficiently repeated to be recommended.

SUMMARY

During the past 18 months, studies have been published that cover risk factors, neuronal mechanisms, and treatment. These recent results do not differ from previous understandings, but the role of cognition and GABAergic dysfunction should be further investigated, and knowledge about resilience factors is still scarce. Also, a clearer evidence base for medical treatment of psychosis with concurrent amphetamine use is warranted. VIDEO ABSTRACT.

Demographic and mental history-related data predicted occurrence of psychosis in metamphetamine users

Methamphetamine use is increasing worldwide, and the occurrence of psychosis further complicates treatment. This holds also true for Iran. The aim of the present study was to investigate possible predictors of metamphetamine-induced psychosis. 237 methamphetamine users (70.9% with psychosis; mean age: M=33.41 years) took part in the study. A psychiatric interview was performed covering socio-demographic and illness-related information. Male gender, low education, unemployment, being single, a history of mental disorders, and a higher number of previous hospitalizations predicted the occurrence of psychosis, while age and duration of metamphetamine use were excluded from the equation. Socio-demographic and mental illness-related dimension seemed suitable to predict occurrence of psychosis among metamphetamine abusers.

Administration of activated glial condition medium in the nucleus accumbens extended extinction and intensified reinstatement of methamphetamine-induced conditioned place preference

Methamphetamine (METH) is a psychostimulant drug with significant abuse potential and neurotoxic effects. A high percentage of users relapse to use after detoxification and no effective medication has been developed for treatment of METH addiction. Developing evidences indicated the role of glial cells in drugs abused related phenomena. However, little is known about the role of these cells in the maintenance and reinstatement of METH-seeking behaviors. Therefore, the current study was conducted to clarify the role of glial cells in the maintenance and reinstatement of METH-induced conditioned place preference (CPP) in rats. Astrocyte condition medium (ACM) and neuroglia conditioned medium (NCM) are liquid mediums prepared from primary astrocyte and neuroglia cells. These mediums seem to contain many factors that release by glia cells. CPP was induced by systemic administration of METH (1mg/kg for 5days, s.c.). Following the establishment of CPP, the rats were given daily bilateral injections (0.5μl/side) of either vehicle, ACM or NCM into the nucleus accumbens (NAc) and then were tested for the maintenance and reinstatement. Intra-NAc administration of ACM treated with METH, could extend the extinction period and also, intensified the magnitude of METH reinstatement. Furthermore, intra-accumbal administration of NCM treated with METH notably delayed the extinction period by four days and significantly increased the magnitude of CPP score in the reinstatement phase compared to the post-test phase. Collectively, these findings suggested that activation of glial cells may be involved in the maintenance and reinstatement of METH-seeking behaviors. It provides new evidence that glia cells might be considered as a potential target for the treatment of METH addiction.

Brain regions and monoaminergic neurotransmitters that are involved in mouse ambulatory activity promoted by bupropion

Bupropion (BUP), a substituted phenyl-ethylamine, has been utilized for the treatment of depression and for smoking cessation, however, one concern is that BUP may increase a risk of psychosis similar to other substituted phenyl-ethylamine amphetamine (AMPH) and methamphetamine (MetAMPH). BUP promotes ambulation in mice and causes behavioral sensitization on the ambulation-promoting effect when repeatedly administered as well as AMPH and MetAMPH. The present study aimed to elucidate brain regions and monoaminergic neurotransmitters that are involved in the ambulation-promoting effect of BUP. c-Fos-like immunoreactivity (c-Fos-IR) mapping in brain in combination with measuring ambulatory activity was conducted to determine brain region(s) that is involved in the ambulatory effect of BUP. Three kinds of statistical analyses for c-Fos-IR in 24 brain regions consistently showed that c-Fos-IR in the Caudate putamen (CPu) is positively correlated with the ambulatory response to BUP. In addition, multiple regression analysis indicated that the ambulatory response is a function of c-Fos-IR not only in the CPu but also in the lateral septum nucleus (LS), median raphe nucleus (MnR), lateral globus pallidus (LGP), medial globus pallidus (MGP), locus coeruleus (LC) and ventral hypothalamic nucleus (VMH). Effects of BUP on monoaminergic neurotransmitters in the CPu were examined using in vivo microdialysis method, as the pharmacological experiments indicated that monoaminergic neurotransmitters, dopamine (DA) in particular, mediate the ambulatory response to BUP. Response of DA in the CPu to BUP was parallel to the ambulatory response, showing that DA in the CPu is involved in the ambulatory response to BUP. The present study also suggests that other brain regions such as the LC, the origin nucleus of norepinephrine (NE) neurons, and another neurotransmitter NE may also play some roles for the ambulatory response to BUP, however, further studies are needed to elucidate the roles.

Candidate gene networks and blood biomarkers of methamphetamine-associated psychosis: an integrative RNA-sequencing report

The clinical presentation, course and treatment of methamphetamine (METH)-associated psychosis (MAP) are similar to that observed in schizophrenia (SCZ) and subsequently MAP has been hypothesized as a pharmacological and environmental model of SCZ. However, several challenges currently exist in diagnosing MAP accurately at the molecular and neurocognitive level before the MAP model can contribute to the discovery of SCZ biomarkers. We directly assessed subcortical brain structural volumes and clinical parameters of MAP within the framework of an integrative genome-wide RNA-Seq blood transcriptome analysis of subjects diagnosed with MAP (N=10), METH dependency without psychosis (MA; N=10) and healthy controls (N=10). First, we identified discrete groups of co-expressed genes (that is, modules) and tested them for functional annotation and phenotypic relationships to brain structure volumes, life events and psychometric measurements. We discovered one MAP-associated module involved in ubiquitin-mediated proteolysis downregulation, enriched with 61 genes previously found implicated in psychosis and SCZ across independent blood and post-mortem brain studies using convergent functional genomic (CFG) evidence. This module demonstrated significant relationships with brain structure volumes including the anterior corpus callosum (CC) and the nucleus accumbens. Furthermore, a second MAP and psychoticism-associated module involved in circadian clock upregulation was also enriched with 39 CFG genes, further associated with the CC. Subsequently, a machine-learning analysis of differentially expressed genes identified single blood-based biomarkers able to differentiate controls from methamphetamine dependents with 87% accuracy and MAP from MA subjects with 95% accuracy. CFG evidence validated a significant proportion of these putative MAP biomarkers in independent studies including CLN3, FBP1, TBC1D2 and ZNF821 (RNA degradation), ELK3 and SINA3 (circadian clock) and PIGF and UHMK1 (ubiquitin-mediated proteolysis). Finally, focusing analysis on brain structure volumes revealed significantly lower bilateral hippocampal volumes in MAP subjects. Overall, these results suggest similar molecular and neurocognitive mechanisms underlying the pathophysiology of psychosis and SCZ regardless of substance abuse and provide preliminary evidence supporting the MAP paradigm as an exemplar for SCZ biomarker discovery.

The profile of psychiatric symptoms exacerbated by methamphetamine use

BACKGROUND

Methamphetamine use can produce symptoms almost indistinguishable from schizophrenia. Distinguishing between the two conditions has been hampered by the lack of a validated symptom profile for methamphetamine-induced psychiatric symptoms. We use data from a longitudinal cohort study to examine the profile of psychiatric symptoms that are acutely exacerbated by methamphetamine use.

METHODS

164 methamphetamine users, who did not meet DSM-IV criteria for a lifetime primary psychotic disorder, were followed monthly for one year to assess the relationship between days of methamphetamine use and symptom severity on the 24-item Brief Psychiatric Rating Scale. Exacerbation of psychiatric symptoms with methamphetamine use was quantified using random coefficient models. The dimensions of symptom exacerbation were examined using principal axis factoring and a latent profile analysis.

RESULTS

Symptoms exacerbated by methamphetamine loaded on three factors: positive psychotic symptoms (suspiciousness, unusual thought content, hallucinations, bizarre behavior); affective symptoms (depression, suicidality, guilt, hostility, somatic concern, self-neglect); and psychomotor symptoms (tension, excitement, distractibility, motor hyperactivity). Methamphetamine use did not significantly increase negative symptoms. Vulnerability to positive psychotic and affective symptom exacerbation was shared by 28% of participants, and this vulnerability aligned with a past year DSM-IV diagnosis of substance-induced psychosis (38% vs. 22%, χ(2)(df1)=3.66, p=0.056).

CONCLUSION

Methamphetamine use produced a symptom profile comprised of positive psychotic and affective symptoms, which aligned with a diagnosis of substance-induced psychosis, with no evidence of a negative syndrome.

Differences in Clinical Features of Methamphetamine Users with Persistent Psychosis and Patients with Schizophrenia

BACKGROUND

Methamphetamine exerts neurotoxic effects and elicits psychotic symptoms. This study attempted to compare clinical differences between methamphetamine users with persistent psychosis (MAP) and patients with schizophrenia. In addition, we examined the discrimination validity by using symptom clusters to differentiate between MAP and schizophrenia.

METHODS

We enrolled 53 MAP patients and 53 patients with schizophrenia. The psychopathology of participants was assessed using the Chinese version of the Diagnostic Interview for Genetic Studies and the 18-item Brief Psychiatric Rating Scale. Logistic regression was used to examine the predicted probability scores of different symptom combinations on discriminating between MAP and schizophrenia. The receiver operating characteristic (ROC) analyses and area under the curve (AUC) were further applied to examine the discrimination validity of the predicted probability scores on differentiating between MAP and schizophrenia.

RESULTS

We found that MAP and schizophrenia demonstrated similar patterns of delusions. Compared to patients with schizophrenia, MAP experienced significantly higher proportions of visual hallucinations and of somatic or tactile hallucinations. However, MAP exhibited significantly lower severity in conceptual disorganization, mannerism/posturing, blunted affect, emotional withdrawal, and motor retardation compared to patients with schizophrenia. The ROC analysis showed that a predicted probability score combining the aforementioned 7 items of symptoms could significantly differentiate between MAP and schizophrenia (AUC = 0.77).

CONCLUSION

Findings in the current study suggest that nuanced differences might exist in the clinical presentation of secondary psychosis (MAP) and primary psychosis (schizophrenia). Combining the symptoms as a whole may help with differential diagnosis for MAP and schizophrenia.