Comparisons of methamphetamine psychotic and schizophrenic symptoms: a differential item functioning analysis

Assessment of rTMS treatment effects for methamphetamine use disorder based on EEG microstates

Microstates have been proposed as topographical maps representing large-scale resting-state networks and have recently been suggested as markers for methamphetamine use disorder (MUD). However, it is unknown whether and how they change after repetitive transcranial magnetic stimulation (rTMS) intervention. This study included a comprehensive subject population to investigate the effect of rTMS on MUD microstates. 34 patients with MUD underwent a 4-week randomized, double-blind rTMS intervention (active=17, sham=17). Two resting-state EEG recordings and VAS evaluations were conducted before and after the intervention period. Additionally, 17 healthy individuals were included as baseline controls. The modified k-means clustering method was used to calculate four microstates (MS-A∼MS-D) of EEG, and the FC network was also analyzed. The differences in microstate indicators between groups and within groups were compared. The durations of MS-A and MS-B microstates in patients with MUD were significantly lower than that in HC but showed significant improvements after rTMS intervention. Changes in microstate indicators were found to be significantly correlated with changes in craving level. Furthermore, selective modulation of the resting-state network by rTMS was observed in the FC network. The findings indicate that changes in microstates in patients with MUD are associated with craving level improvement following rTMS, suggesting they may serve as valuable evaluation markers.

Positive and negative symptoms in methamphetamine-induced psychosis compared to schizophrenia: A systematic review and meta-analysis

BACKGROUND

The clinical profiles of methamphetamine-induced psychosis (MIP) and schizophrenia are largely overlapping making differentiation challenging. In this systematic review and meta-analysis, we aim to compare the positive and negative symptoms of MIP and schizophrenia to better understand the differences between them.

STUDY DESIGN

In accordance with our pre-registered protocol (CRD42021286619), we conducted a search of English-language studies up to December 16th, 2022, in PubMed, EMBASE, and PsycINFO, including stable outpatients with MIP and schizophrenia. We used the Newcastle-Ottawa Scale to measure the quality of cross-sectional, case-control, and cohort studies.

STUDY RESULTS

Of the 2052 articles retrieved, we included 12 studies (6 cross-sectional, 3 case-control, and 2 cohort studies) in our meta-analysis, involving 624 individuals with MIP and 524 individuals with schizophrenia. Our analysis found no significant difference in positive symptoms between the two groups (SMD, -0.01; 95%CI, -0.13 to +0.11; p = 1). However, individuals with MIP showed significantly less negative symptoms compared to those with schizophrenia (SMD, -0.35; 95CI%, -0.54 to -0.16; p = 0.01; I2 = 54 %). Our sensitivity analysis, which included only studies with a low risk of bias, did not change the results. However, our meta-analysis is limited by its cross-sectional approach, which limits the interpretation of causal associations. Furthermore, differences in population, inclusion criteria, methodology, and drug exposure impact our findings.

CONCLUSIONS

Negative symptoms are less prominent in individuals with MIP. While both groups do not differ regarding positive symptoms, raises the possibility of shared and partly different underlying neurobiological mechanisms related to MIP and schizophrenia.

Lymphocyte-related ratios in methamphetamine-induced psychotic disorder in Taiwan, comparing with patients with schizophrenia

The lymphocyte-related ratios, neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR) and platelet-to-lymphocyte ratio (PLR) are new measures of inflammation within the body. Few studies have investigated the inflammatory response of patients with methamphetamine-induced psychotic disorder. Clinically, the psychotic symptoms and behavioural manifestation of methamphetamine-induced psychotic disorder are often indistinguishable from paranoid schizophrenia. We aimed to determine the differences in these inflammatory markers between patients with methamphetamine-induced psychotic disorder, patients with schizophrenia and healthy individuals. A total of 905 individuals were recruited. The NLR and MLR were found to be higher in both patients with methamphetamine-induced psychotic disorders and patients with schizophrenia compared with healthy controls. There was no significant difference between the three groups in PLR. When compared with the control group, the methamphetamine-induced psychotic disorder group was significantly higher in NLR 27% (95%CI = 11 to 46%, p = 0.001), MLR 16% (95%CI = 3% to 31%, p = 0.013) and PLR 16% (95%CI = 5% to 28%, p = 0.005). NLR of the group with methamphetamine-induced psychotic disorder was 17% (95%CI = 73% to 94%, p = 0.004) less than the group with schizophrenia, while MLR and PLR did not differ significantly between the two groups. This is the first study that investigated the lymphocyte-related ratios in methamphetamine-induced psychotic disorder when compared with patients with schizophrenia and healthy individuals. The results showed that both patients with methamphetamine-induced psychotic disorder and patients with schizophrenia had stronger inflammatory responses than the healthy control. Our finding also indicated that the inflammatory response of methamphetamine-induced psychotic disorder was between those of patients with schizophrenia and healthy individuals.

Evaluation of the BEAT Meth Intervention for Emergency Department Patients with Methamphetamine Psychosis

OBJECTIVES

Methamphetamine is the second leading cause of overdose death in America and a leading cause of emergency department (ED) visits. Methamphetamine-induced psychosis is a dangerous and difficult-to-treat consequence of methamphetamine use. We describe the pilot implementation and outcomes of a multimodal treatment intervention for ED patients with methamphetamine psychosis, Beginning Early and Assertive Treatment for Methamphetamine Psychosis (BEAT Meth).

METHODS

BEAT Meth was implemented in an urban safety net health system. The protocol includes early identification and treatment of methamphetamine psychosis, a protocolized hospitalization, and support for transitioning patients to specialty addiction treatment. Patients receiving BEAT Meth were compared with ED patients with methamphetamine psychosis who were discharged. Implementation fidelity was measured to assess feasibility.

RESULTS

BEAT Meth patients were nearly 3 times more likely to attend an outpatient specialty addiction appointment in the 30 days after discharge than comparison patients (32% vs 11%, P < 0.01). Subsequent ED utilization was common among all patients, and there was no significant difference in 30-day ED return rates between BEAT Meth and comparison patients (28% vs 37%, P = 0.10). Exploratory analyses suggested that increased attendance at outpatient treatment reduced ED utilization.

CONCLUSIONS

BEAT Meth is an intervention framework to support identification, management, and treatment engagement of ED patients with methamphetamine psychosis. Treatment strategies like BEAT Meth are necessary to manage the unique challenges of methamphetamine addiction. These findings will guide clinical care, program development, and research.

Differences in small-world networks between methamphetamine and heroin use disorder patients and their relationship with psychiatric symptoms

Both methamphetamine use disorder (MAUD) and heroin use disorder (HUD) implicated in substance-induced psychosis, but the psychiatirc symptoms induced by MAUD and HUD are significantly different. The functional network organizations that may underlie these differences remains unknown. Image data was acquired by resting-state fMRI from 19 MAUD patients, 21 HUD patients, and 20 healthy controls. The small-world properties, node attributes, and functional connectivity of brain regions were analyzed among the three groups. Psychiatric status was evaluated by the Symptom Checklist 90 in all participants. The MAUD patients had significantly higher psychiatric scores than the controls and HUD patients. Both MAUD and HUD patients still had economical small-world properties. The MAUD patients showed increased nodal efficiency and betweenness centrality in the right inferior occipital gyrus, left insular lobe, bilateral Heschl gyrus, and bilateral superior temporal gyrus, while the node attributes decreased in the right parahippocampal gyrus and right hippocampus compared to the HUD patients. The MAUD patients also showed reduced edge connectivity between left dorsolateral prefrontal cortex (dlPFC) and left middle occipital gyrus (MOG), as well as between bilateral orbitofrontal cortex (OFC) and bilateral superior occipital gyrus (SOG), left MOG, or right cuneus. In the MAUD group, the functional connection between left dlPFC and left MOG was negatively correlated with depression, while the connection between right cuneus lobe and right OFC was negatively correlated with depression and interpersonal sensitivity. These brain regions related to cognitive, emotional, and auditory/visual regulation may play an important role in the psychiatric symptoms of MAUD.

Psychopathology and Poor Clinical Insight in Psychotic Patients: Does the Diagnosis Matter?

ABSTRACT

Poor clinical insight is one of the most common features of schizophrenia spectrum disorders and plays a critical role in prognosis and treatment. Considering the biological and phenomenological overlap between schizophrenia and bipolar I disorder with psychotic features (BID) and increasing incidents of methamphetamine-induced psychotic disorder (MIPD) patients in Iran, it is necessary to have a clear picture of insight among these three groups. The aim of the present study was to compare clinical insight and other aspects of illness among three different disorders: schizophrenia, BID, and MIPD. In addition, we sought to examine the relationship of the severity of psychotic symptoms with clinical insight in each group. A total of 115 male inpatients, including 48 persons diagnosed with schizophrenia, 35 persons diagnosed with BID, and 32 persons diagnosed with MIPD, were selected. All participants completed the Scale to Assess Unawareness of Mental Disorder and the Positive and Negative Syndrome Scale. The results of analysis of variance indicated that schizophrenia patients reported higher rates of illness duration and number of hospital admissions in comparison to the MIPD and BID groups. In addition, persons diagnosed with BID reported more of these outcomes than MIPD groups. However, the three groups showed similar patterns in terms of age of onset and educational, marital, and occupational statuses. The results also revealed that awareness of the disorder was more impaired in schizophrenia patients compared with BID and MIPD patients and in MIPD compared with BID groups. However, the level of awareness of the effect of medication, the awareness of social consequences, and the total score of clinical insight were similar across the three diagnostic groups. As expected, poor clinical insight was correlated with high levels of positive, negative, and cognitive symptoms in the schizophrenia group; with high levels of positive, cognitive, and depressive symptoms in the BID group; and with high levels of positive and excitement symptoms in MIPD. In addition, hierarchical linear regression analyses revealed that only cognitive symptoms in the schizophrenia group and excitement symptoms in the MIPD group significantly predicted the overall score of clinical insight. In the BID group, both cognitive and depressive symptoms significantly predicted clinical insight. These findings suggest that there are differing levels of poor clinical insight in schizophrenia, MIPD, and BID and that poor clinical insight found within each group may have different antecedents.

A latent class analysis of psychiatric symptom profiles associated with past-month methamphetamine use

We explored latent psychiatric symptom profiles associated with methamphetamine use, and examined how these corresponded to diagnoses of schizophrenia (SZ) and methamphetamine-associated psychosis (MAP). We assessed psychiatric symptoms among 160 people who had used methamphetamine in the past month. Psychiatric symptoms were defined as a score of 4+ on Brief Psychiatric Rating Scale (BPRS) items. Diagnoses were made using the Composite International Diagnostic Interview (CIDI). Participants were defined as having MAP if they met symptom criteria for SZ, but symptoms were considered to be always the result of substance use. Latent class analysis identified three classes. Class one (44% of participants) had a low probability of most BPRS symptoms; 4% met criteria for SZ, 51% for MAP. Class two (31% of participants) had a higher probability hallucinations and suspiciousness (37-46%); 72% met criteria for MAP, and 7% for SZ. Class three (25% of participants) had the highest probability for all positive psychotic symptoms (hallucinations, suspiciousness, grandiosity, unusual thought content; 32-82%), and reported activation, conceptual disorganisation, and tension (35% met criteria for SZ and 17% for MAP). We found three distinct classes of psychiatric symptom profiles, two of which showed partial alignment with diagnostic constructs of SZ and MAP.

[Differential diagnostic distinction between substance-induced and primary psychoses: : Recommendations for general psychiatric and forensic practice]

Substanzinduzierte psychotische Störungen (SIPS) sind häufig und für ca. 25 % der ersten Einweisungen in eine psychiatrische Klinik verantwortlich. Aus klinischer Sicht ist aufgrund ähnlicher psychopathologischer Phänomene die diagnostische Unterscheidung zwischen SIPS und primären (genuinen oder kryptogenen) psychotischen Störungen oft eine Herausforderung. Dieser Umstand wird dadurch erschwert, dass SIPS im Zusammenhang mit Cannabis, Halluzinogenen und Amphetaminen ein erhebliches Risiko des Übergangs in eine primäre psychotische Störung (z. B. Schizophrenie) haben. Im ersten Abschnitt dieser Arbeit werden zunächst zwei exemplarische Fallvignetten aus der allgemeinpsychiatrischen und forensischen Praxis vorgestellt. Danach wird im Sinne einer selektiven Literaturübersicht die Relevanz der differenzialdiagnostischen Unterscheidung beider Störungsbilder aus der Sicht der allgemeinen und forensischen Psychiatrie in Bezug auf Therapie, Prognose und richterliche Entscheidung bezüglich der Unterbringung im Maßregelvollzug (§ 63 vs. § 64 StGB) beleuchtet. Der letzte Abschnitt hat das Ziel, ein strukturiertes Vorgehen zur differenzialdiagnostischen Unterscheidung zwischen SIPS und primären psychotischen Störungen zu erarbeiten. Die in dieser Arbeit dargestellten und diskutierten Konzepte und Befunde sollen klinisch tätigen Psychiatern und Psychologen die Diagnosestellung im allgemeinen und forensischen Kontext erleichtern.

Efficacy and dropout rates of antipsychotic medications for methamphetamine psychosis: A systematic review and network meta-analysis

BACKGROUND

This study aimed to compare the treatment effects of different antipsychotics for methamphetamine psychosis (MAP).

METHODS

Clinical Trials, Cochrane Library, Pubmed, Scopus, and Web of Science were searched for short-term, randomized controlled trials (RCTs) from the inception to June 15, 2020. Standardized mean differences (SMDs) and odds ratios (ORs) were aggregated using random-effects pairwise comparisons and frequentist network meta-analyses (NMAs). Primary outcomes of interest were the main psychotic symptoms and dropout rates. We also rated the quality of NMA estimates.

RESULTS

This NMA included six RCTs of 395 patients with MAP. Six studied antipsychotics were aripiprazole, haloperidol, olanzapine, paliperidone extended-release, quetiapine, and risperidone. Risperidone is the most frequently studied antipsychotic, being investigated in four trials. Low quality of evidence was available to determine the efficacy of those antipsychotics for main psychotic symptoms. Aripiprazole was significantly inferior to olanzapine (SMD = 1.36, 95 % CI = 0.46-2.26), quetiapine (SMD = 1.13, 95 % CI = 0.28-1.98), haloperidol (SMD = 0.87, 95 % CI = 0.14-1.60), and paliperidone extended-release (SMD = 0.60, 95 % CI = 0.06-1.14). Olanzapine and quetiapine were superior to risperidone (SMD = -1.09, 95 % CI = -1.89 to -0.28 and SMD = -0.86, 95 % CI = -1.61 to -0.11, respectively). The dropout rates were not significantly different among the studied antipsychotics.

CONCLUSIONS

This analysis suggests that olanzapine or quetiapine may be a preferred antipsychotic for MAP, although the evidence for this was rated low-quality due to the high risk of bias or indirectness/intransitivity.

Treatment Response Distinguishes Persistent Type of Methamphetamine Psychosis From Schizophrenia Spectrum Disorder Among Inmates at Japanese Medical Prison

Introduction: Persistent methamphetamine-associated psychosis (pMAP) is a disorder similar to schizophrenia, so much so that the differences in clinical symptoms and treatment response between the two remain unknown. In this study, we compared the features of pMAP with those of schizophrenia spectrum disorders (SSD). Materials and Methods: This was a retrospective quasi-experimental case-control study of inmates in a medical prison. The behavioral problems, clinical symptoms, and chlorpromazine (CP)-equivalent doses of 24 patients with pMAP and 27 with SSD were compared. Results: Patients in the pMAP group were hospitalized for fewer days than those in the SSD group (281.5 vs. 509.5; p = 0.012), but there were no other significant group differences in behavioral problems or clinical symptoms. The pMAP group received fewer antipsychotics in CP-equivalent doses than the SSD group at 4, 8, and 12 weeks after admission and at the time of discharge (p = 0.018, 0.001, 0.007, and 0.023, respectively). The number of CP-equivalent doses in the SSD group tended to increase after admission, but not in the pMAP group. Discussion: These findings suggest that differentiation between pMAP and SSD based on behavior and symptoms alone may be difficult, and that patients with pMAP may respond better to treatment with a lower dose of antipsychotic medication than those with SSD. Further confirmatory studies are warranted.

Disrupted brain network dynamics and cognitive functions in methamphetamine use disorder: insights from EEG microstates

BACKGROUND

Dysfunction in brain network dynamics has been found to correlate with many psychiatric disorders. However, there is limited research regarding resting electroencephalogram (EEG) brain network and its association with cognitive process for patients with methamphetamine use disorder (MUD). This study aimed at using EEG microstate analysis to determine whether brain network dynamics in patients with MUD differ from those of healthy controls (HC).

METHODS

A total of 55 MUD patients and 27 matched healthy controls were included for analysis. The resting brain activity was recorded by 64-channel electroencephalography. EEG microstate parameters and intracerebral current sources of each EEG microstate were compared between the two groups. Generalized linear regression model was used to explore the correlation between significant microstates with drug history and cognitive functions.

RESULTS

MUD patients showed lower mean durations of the microstate classes A and B, and a higher global explained variance of the microstate class C. Besides, MUD patients presented with different current density power in microstates A, B, and C relative to the HC. The generalized linear model showed that MA use frequency is negatively correlated with the MMD of class A. Further, the generalized linear model showed that MA use frequency, scores of Two-back task, and the error rate of MA word are correlated with the MMD and GEV of class B, respectively.

CONCLUSIONS

Intracranial current source densities of resting EEG microstates are disrupted in MUD patients, hence causing temporal changes in microstate topographies, which are correlated with attention bias and history of drug use.

Methamphetamine-associated psychosis: links to drug use characteristics and similarity to primary psychosis

Objectives: Despite the prevalence of methamphetamine-associated psychosis, how characteristics of drug use affect the severity and clinical course, and its optimal treatments have not been established. We addressed these questions, assessing clinical features of methamphetamine-associated psychosis, and compared it with primary psychosis.Methods: Hospitalised patients with methamphetamine-associated (n = 70) or primary schizophrenic psychosis (n = 70) were matched on sex, age and duration of psychosis. Association of drug use variables (age at initiation, duration of methamphetamine use) with the Brief Psychiatric Rating Scale (BPRS) scores and psychosis duration were examined for patients with methamphetamine-associated psychosis, and the groups were compared on the BPRS scores.Results: Methamphetamine use initiation age correlated negatively with the BPRS total score and the Activation subscale score; methamphetamine use duration correlated positively with psychosis duration. Methamphetamine-associated psychosis group scored lower on the Hostility-Suspiciousness and Anergia subscales of the BPRS (adjusted p values < .05).Conclusions: Association of early initiation of methamphetamine with psychosis severity may suggest a lasting effect on brain development. Correlation of drug use and psychosis durations may suggest a cumulative effect of methamphetamine exposure. Less severe paranoia and negative symptoms in the methamphetamine-using group could implicate better social functioning of these patients. Further mechanistic studies are warranted.Key pointsEarly initiation of methamphetamine use is associated with psychosis severity.Methamphetamine use duration associates with psychosis duration.Methamphetamine-associated and primary schizophrenic psychoses were similar in symptoms.Methamphetamine psychosis patients were less severe in paranoia and negative symptoms.

Lower folate levels in methamphetamine-induced psychosis: A cross-sectional study

BACKGROUND

Folate deficiency is shown to be associated with schizophrenia. Folate profile in patients with psychosis due to stimulant use has not been investigated. We aim to determine whether there is an association between serum folate level and the presence of psychosis in patients with methamphetamine (METH) use disorder.

METHODS

Forty patients diagnosed with METH-use disorder were included in this cross-sectional study. Serum folate levels were measured using enzyme immunoassay technique and compared between psychotic and non-psychotic subgroups (N = 25 and 15, respectively). We designed a logistic regression model to measure the extent of any association and also to adjust for potential confounders.

RESULTS

We detected lower serum folate level in the psychotics [3.4 (IQR = 5.3)] compared to non-psychotic METH users [8.9 (IQR = 2.5)], p = 0.01. The model demonstrated that every 1-unit increase in serum folate decreases the odds of presence of psychosis by 27% (R² = 53.5%, CI 12-64%, p = 0.006). The observed difference was not associated with the duration of METH use, patient's age at first METH use, or concurrent use of other substances.

CONCLUSIONS

Our findings suggest that low folate level in psychotic METH users does not correlate with previously established risk factors for meth-induced psychosis such as duration of use, age of onset of using, and poly-drug use. We assume that low folate levels may play a crucial role in the pathophysiology of psychosis.

Mental health outcomes associated with of the use of amphetamines: A systematic review and meta-analysis

BACKGROUND

The use of amphetamines is a global public health concern. We summarise global data on use of amphetamines and mental health outcomes.

METHODS

A systematic review and meta-analysis (CRD 42017081893). We searched Medline, EMBASE, PsycInfo for methamphetamine or amphetamine combined with psychosis, violence, suicidality, depression or anxiety. Included studies were human empirical cross-sectional surveys, case-control studies, cohort studies and randomised controlled trials that assessed the association between methamphetamine and one of the mental health outcomes. Random effects meta-analysis was used to pool results for any use of amphetamines and amphetamine use disorders.

FINDINGS

149 studies were eligible and 59 were included in meta-analyses. There was significant heterogeneity in effects. Evidence came mostly from cross-sectional studies. Any use of amphetamines was associated with higher odds of psychosis (odds ratio [OR] = 2.0, 95%CI 1.3-3.3), violence (OR = 2.2, 95%CI 1.2-4.1; adjusted OR [AOR] = 1.4, 95%CI 0.8-2.4), suicidality OR = 4.4, 95%CI 2.4-8.2; AOR = 1.7, 95%CI 1.0-2.9) and depression (OR = 1.6, 95%CI 1.1-2.2; AOR = 1.3, 95%CI 1.2-1.4). Having an amphetamine use disorder was associated with higher odds of psychosis (OR = 3.0, 95%CI 1.9-4.8; AOR = 2.4, 95%CI 1.6-3.5), violence (OR = 6.2, 95%CI 3.1-12.3), and suicidality (OR = 2.3, 95%CI 1.8-2.9; AOR = 1.5, 95%CI 1.3-1.8).

INTERPRETATION

Methamphetamine use is an important risk factor for poor mental health. High quality population-level studies are needed to more accurately quantify this risk. Clinical responses to methamphetamine use need to address mental health harms.

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.

Risks of psychosis in methamphetamine users: cross-sectional study in Thailand

OBJECTIVE

To determine factors related to recent methamphetamine-associated psychosis (MAP) among individuals recently using methamphetamine (MA).

DESIGN

Cross-sectional study carried out between July 2015 and June 2017.

SETTING

Four mental health hospitals and one substance abuse treatment centre in Thailand.

PARTICIPANTS

Individuals recruited onto the study included those aged 18 years or over, of both sexes, who reported MA use in the month prior to admission.

MEASURES

Any recent psychosis was confirmed using the Mini International Neuropsychiatric Interview-Plus psychotic module. The Timeline Follow Back was used to determine days of MA use. The severity of MA dependence was assessed using the Severity of Dependence Scale. Quantitative hair analysis was carried out to confirm recent use of MA and to measure the amount of MA use. We compared several characteristics between those who had recently experienced psychosis and those who had not.

RESULTS

This study included 120 participants without MAP and 113 participants with MAP. The mean age was 28 years and the mean abstinence was 17 days. The levels of MA concentration in hair were not significantly different between groups (p=0.115). Based on the final logistic regression model, the independent factors associated with MAP (OR and 95% CI) included being male (OR 4.03, 95% CI 1.59 to 10.20), ≥16 days of MA use in the past month (OR 2.35, 95% CI 1.22 to 4.52), MA dependence (OR 9.41, 95% CI 2.01 to 44.00) and hospitalisation history related to substance abuse (OR 3.85, 95% CI 2.03 to 7.28).

CONCLUSIONS

Health professionals should closely monitor the development of MAP in MA-dependent men who frequently use MA and have a history of hospitalisation for substance abuse. The measure of MA concentration levels in the hair may add no benefit for the prediction of the development of MAP.

Is there a discrete negative symptom syndrome in people who use methamphetamine?

BACKGROUND

Positive psychotic symptoms have consistently been associated with methamphetamine use but the presence of a negative symptom cluster remains unclear. We used exploratory factor analysis to examine whether a discrete negative syndrome could be delineated among methamphetamine users, and to examine the clinical correlates of this syndrome.

METHOD

Participants (N = 154) were people who used methamphetamine at least monthly and did not meet DSM-IV diagnostic criteria for lifetime schizophrenia. Scores on the Brief Psychiatric Rating Scale for the past month were subject to exploratory factor analysis. Latent class analysis was applied to resultant factor scores to determine whether negative and positive factors were experienced by the same participants. Past-month substance use measures were days of use for each drug type and methamphetamine dependence assessed using the Severity of Dependence Scale.

RESULTS

We articulated a three-factor model including 'positive/activation symptoms' (e.g. suspiciousness, hallucinations, conceptual disorganisation, tension), 'affective symptoms' (e.g. depression, anxiety) and 'negative symptoms' (e.g. blunted affect, motor retardation). Positive-activation and affective symptoms (but not negative symptoms) were positively correlated with past month days of methamphetamine use (r = 0.16; r = 0.25) and severity of dependence (r = 0.24; r = 0.41). Negative symptoms were correlated with heroin (r = 0.24) and benzodiazepine use (r = 0.21). Latent class analysis revealed a three-class model comprising a positive-symptom class (44%, high positive-activation, low negative symptoms), a negative-symptom class (31%, low positive-activation, high negative symptoms), and a low-symptom class (38%, low on all factors).

CONCLUSIONS

A negative symptom syndrome exists among people who use methamphetamine, but this appears related to polysubstance use rather than forming a part of the psychotic syndrome associated with methamphetamine use. Overlooking the role of polysubstance use on negative symptoms may conflate the profiles of methamphetamine-associated psychosis and schizophrenia.

A Systematic Review of the Symptom Profile and Course of Methamphetamine-Associated PsychosisSubstance Use and Misuse

OBJECTIVES

The psychiatric symptom profile of methamphetamine-associated psychosis (MAP) has varied considerably across studies of different research designs. We performed a systematic review to examine the available evidence for specific psychotic symptoms associated with MAP, including the clinical course and longitudinal changes in this symptom profile.

METHODS

Five key electronic databases were searched to identify studies that examined the symptom profile or clinical course of MAP in individuals identified as having MAP. The reporting of specific psychiatric symptoms, and duration of symptoms where available, was recorded for each study.

RESULTS

Ninety-four articles were identified (n = 7387), including case-control (k = 29), cross-sectional (k = 20), experimental (k = 6), case report (k = 29), and longitudinal (k = 20) studies. Persecutory delusions, auditory and visual auditory hallucinations were by far the most commonly reported symptoms (reported in 65-84% of studies). Hostility, conceptual disorganization, and depression were reported in a large proportion of studies (31-53%). Negative symptoms were mostly absent (<20%). The median percentage of participants with persistent psychotic symptoms (>1 month duration) across studies was 25% (excluding case reports).

CONCLUSION

Persecutory delusions, auditory and visual hallucinations, hostility, depression and conceptual disorganization are central to MAP, whereas negative psychotic symptoms are typically absent. An overrepresentation of institutionalized or male participants may have overemphasized negative symptoms and underreported affective symptoms in past research. Symptoms of MAP may persist beyond one month after drug cessation in some individuals. Clinicians are encouraged to manage affective symptoms in MAP individuals, and monitor for the development of chronic psychotic symptoms.

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.

Spicing it up - synthetic cannabinoid receptor agonists and psychosis - a systematic review

Synthetic cannabinoid receptor agonists (SCRAs) are suggested to have increased potential to induce psychosis compared to natural cannabis (NC). In this review we synthesise current knowledge about the association of SCRA use with psychotic symptoms. Following a literature search we identified 2 toxicology reports, 4 case-control studies, 3 cross-sectional studies and 15 case reports. In each of the case reports, we identified the presence or absence of symptoms based on the items of the Postitive and Negative Syndrome Scele (PANSS). The toxicology reports highlighted the main presenting features as being toxic psychosis and delirium (40%), agitation (10%) and hallucinations (4-7%). The median age was 25 years, and around 80% cases were male. Cross-sectional studies reported that SCRA use was present in approximately 10-13% patients presenting to acute psychiatric services, and was often the cause of their presentation, and that psychotic symptoms were present in 15% patients attending emergency departments following SCRA use. Case-control studies reported that SCRA use was significantly associated with psychotic symptoms and that SCRA users had higher levels of positive psychotic symptoms than NC users. The case reports supported the association of SCRA use with a wide range of positive and negative psychotic symptoms as well as with self-harm, agitation and aggressive behaviour. SCRA use is relatively prevalent in patients with psychosis and may lead to psychotic symptoms in individuals with no past psychiatric history. Further work is required to understand the long term risks of SCRA use and optimal management strategies.

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.

Twelve-month course and outcome of methamphetamine-induced psychosis compared with first episode primary psychotic disorders

BACKGROUND

To assess the clinical course and outcome of patients with methamphetamine-induced psychosis in comparison with patients with primary psychotic disorders.

METHODS

This prospective study was conducted on patients with methamphetamine-induced psychosis, and 2 groups of primary psychotic disorders: affective psychosis and non-affective psychosis admitted to 2 psychiatric hospitals in Tehran, Iran, with a first episode of a psychotic illness. A total of 165 subjects (55 in each group) were selected using convenience sampling. They were assessed at the time of admission, discharge and 6 and 12 months after discharge using the Positive and Negative Syndrome Scale, the Young Mania Rating Scale and the Global Assessment of Functioning Scale. The frequency of readmissions and suicide attempts were also assessed.

RESULTS

Significant differences were found in the trend of changes of symptoms and functioning among the 3 groups. At all-time points, the severity of negative psychotic symptoms and dysfunction in the non-affective psychosis group were greater than those in affective or methamphetamine-induced psychosis groups, with latter 2 having similar profiles. However, the course of positive symptoms in methamphetamine-induced psychosis was more similar to non-affective psychosis. Number of suicide attempts and readmissions were non-significantly higher in methamphetamine-induced psychosis than in the other groups.

CONCLUSION

Methamphetamine-induced psychosis does not have a satisfactory course and in some cases symptoms may remain even after many months of follow-up. Rate of certain outcomes such as re-hospitalization is also considerably high. It is a challenge for the health-care system that requires evidence-based interventions.

Cognitive Functioning in Schizophrenia, Methamphetamine-induced Psychotic Disorder, and Healthy People: A Comparative Study

Background:

Methamphetamine-induced psychotic disorder (MIP) cannot be easily differentiated from other psychotic disorders. Some studies have reported that patients with MIP and schizophrenia have differences in their cognitive functioning. We hypothesized that their performance would be different on neuropsychological tests which assess executive functions and visual memory.

Materials and Methods:

In a cross-sectional study, 30 patients with MIP, 31 patients with schizophrenia, and 31 healthy controls were assessed by Rey–Osterrieth complex figure (ROCF) test and visual search and attention test (VSAT). One-way analysis of variance was performed to compare the mean scores of tests. Tukey's HSD test was used for post hoc analysis.

Results:

Three groups had significant differences according to ROCF test (F = 15.76, P < 0.0001), VSAT (F = 39.78, P < 0.0001), left VSAT (F = 37.96, P < 0.0001), right VSAT (F = 40.40, P < 0.0001), and the time of the test administration (F = 3.26, P = 0.04). The post hoc analysis showed that the mean score of ROCF test and VSAT (total, right, and left) was significantly higher in the control group than in the other two groups. The time of administering the test in the control group was significantly shorter than in the MIP group (P < 0.03) and nonsignificantly shorter than in the schizophrenia group (P = 0.54). The mean score of right side VSAT was significantly higher in the MIP group than in the schizophrenia group.

Conclusion:

ROCF could not differentiate MIP from schizophrenia. The better performance of patients with MIP on right side VSAT that is reported in this and in the previous study needs to be reevaluated in more controlled studies.

A Comparison of Methamphetamine-Induced Psychosis and Schizophrenia: A Review of Positive, Negative, and Cognitive Symptomatology

Methamphetamine is a potent psychostimulant that can induce psychosis among recreational and chronic users, with some users developing a persistent psychotic syndrome that shows similarities to schizophrenia. This review provides a comprehensive critique of research that has directly compared schizophrenia with acute and chronic METH psychosis, with particular focus on psychiatric and neurocognitive symptomatology. We conclude that while there is considerable overlap in the behavioral and cognitive symptoms between METH psychosis and schizophrenia, there appears to be some evidence that suggests there are divergent aspects to each condition, particularly with acute METH psychosis. Schizophrenia appears to be associated with pronounced thought disorder, negative symptoms more generally and cognitive deficits mediated by the parietal cortex, such as difficulties with selective visual attention, while visual and tactile hallucinations appear to be more prevalent in acute METH-induced psychosis. As such, acute METH psychosis may represent a distinct psychotic disorder to schizophrenia and could be clinically distinguished from a primary psychotic disorder based on the aforementioned behavioral and cognitive sequelae. Preliminary evidence, on the other hand, suggests that chronic METH psychosis may be clinically similar to that of primary psychotic disorders, particularly with respect to positive and cognitive symptomatology, although negative symptoms appear to be more pronounced in schizophrenia. Limitations of the literature and avenues for future research are also discussed.

Latent Psychotic Symptom Profiles Amongst People Who Use Methamphetamine: What Do They Tell Us About Existing Diagnostic Categories?

The inability to distinguish clearly between methamphetamine-related psychosis and schizophrenia has led to the suggestion that "methamphetamine psychosis" does not represent a distinct diagnostic entity but rather that the drug has triggered a vulnerability to schizophrenia. We tested this possibility by exploring the latent class structure of psychotic symptoms amongst people who use the drug and examining how these latent symptom profiles correspond to a diagnosis of schizophrenia. Latent class analysis was carried out on the lifetime psychotic symptoms of 554 current methamphetamine users, of whom 40 met the DSM-IV criteria for schizophrenia. Lifetime diagnoses of schizophrenia and individual psychotic symptoms were assessed using the Composite International Diagnostic Interview. The chosen model found 22% of participants had a high propensity to experience a wide range of psychotic symptoms (schizophrenia-like), whereas the majority (56%) more specifically experienced persecutory delusions and hallucinations (paranoid psychosis) and had a lower probability of these symptoms than the schizophrenia-like class. A third class (22%) had a low probability of all symptoms, with the exception of 34% reporting persecutory delusions. Participants in the schizophrenia-like class were more likely to meet diagnostic criteria for schizophrenia (26 vs. 3 and 1% for each of the other classes, p < 0.001) but the diagnosis failed to encompass 74% of this group. These results are consistent with there being a distinction between schizophrenia and methamphetamine-related psychotic symptoms, both in terms of the propensity to experience psychotic symptoms, as well as the symptom profile; however, this distinction may not be captured well by existing diagnostic classifications.

Increased DNA methylation in the parvalbumin gene promoter is associated with methamphetamine dependence

Aim: The parvalbumin (PV)-containing subgroup of GABAergic neurons is particularly affected in schizophrenia and animal models of psychosis, including after methamphetamine (METH) administration. We investigated whether METH dependence and METH-induced psychosis may involve an effect on DNA methylation of the PVALB promoter. Materials & methods: The methylation of a PVALB promoter sequence was determined in 100 METH-dependent and 102 control subjects using pyrosequencing. Results: A significant increase in PVALB methylation was observed in METH dependence and METH-induced psychosis. No significant effect on long interspersed nucleotide element-1 methylation, a measure of global DNA methylation, was observed. Conclusion: These results demonstrate a specific association between elevated PVALB methylation and METH-induced psychosis. This finding may contribute to the GABAergic deficits associated with METH dependence.

Behavioral sensitization to methamphetamine induces specific interneuronal mRNA pathology across the prelimbic and orbitofrontal cortices

Schizophrenia is associated with significant pathophysiological changes to interneurons within the prefrontal cortex (PFC), with mRNA and protein changes associated with the GABA network localized to specific interneuron subtypes. Methamphetamine is a commonly abused psychostimulant that can induce chronic psychosis and symptoms that are similar to schizophrenia, suggesting that chronic METH induced psychosis may be associated with similar brain pathology to schizophrenia in the PFC. The aim of this study, therefore, was to examine mRNA expression of interneuron markers across two regions of the PFC (prelimbic (PRL) and orbitofrontal cortices (OFC)) following METH sensitization, an animal model of METH psychosis. We also studied the association between GABA mRNA expression and interneuronal mRNA expression to identify whether particular changes to the GABA network could be localized to a specific inhibitory cellular phenotype. METH sensitization increased the transcriptional expression of calbindin, calretinin, somatostatin, cholecyctokinin and vasoactive intestinal peptide in the PRL while parvalbumin, calbindin, cholectokinin and vasoactive intestinal peptide were upregulated in the OFC. Based on our previous findings, we also found significant correlations between GAD₆₇, GAT₁ and parvalbumin while GAD₆₇, GAD₆₅ and GAT₁ were positively correlated with cholecystokinin in the PRL of METH sensitized rats. Within the OFC, the expression of GABA_Aα1 was positively correlated with somatostatin while GABA_Aα5 was negatively associated with somatostatin and calbindin. These findings suggest that METH sensitization differentially changes the expression of mRNAs encoding for multiple peptides and calcium binding proteins across the PRL and the OFC. Furthermore, these findings support that changes to the GABA network may also occur within specific cell types. These results, therefore, provide the first evidence that METH sensitization mediates differential interneuronal pathology across the PRL and OFC and such changes could have profound consequences on behavior and cognitive output.

Differences in the symptom profile of methamphetamine-related psychosis and primary psychotic disorders

We examined the lifetime experience of hallucinations and delusions associated with transient methamphetamine-related psychosis (MAP), persistent MAP and primary psychosis among a cohort of dependent methamphetamine users. Participants were classified as having (a) no current psychotic symptoms, (n=110); (b) psychotic symptoms only when using methamphetamine (transient MAP, n=85); (c) psychotic symptoms both when using methamphetamine and when abstaining from methamphetamine (persistent MAP, n=37), or (d) meeting DSM-IV criteria for lifetime schizophrenia or mania (primary psychosis, n=52). Current psychotic symptoms were classified as a score of 4 or more on any of the Brief Psychiatric Rating Scale items of suspiciousness, hallucinations or unusual thought content in the past month. Lifetime psychotic diagnoses and symptoms were assessed using the Composite International Diagnostic Interview. Transient MAP was associated with persecutory delusions and tactile hallucinations (compared to the no symptom group). Persistent MAP was additionally associated with delusions of reference, thought interference and complex auditory, visual, olfactory and tactile hallucinations, while primary psychosis was also associated with delusions of thought projection, erotomania and passivity. The presence of non-persecutory delusions and hallucinations across various modalities is a marker for persistent MAP or primary psychosis in people who use methamphetamine.

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.

Domestic Violence in Methamphetamine Psychotic Users, Psychiatric Inpatients, and Healthy People: A Comparative Study

BACKGROUND

Domestic violence is a serious threat to the physical and mental health of women. The aim of the present study was to find and compare the frequency of domestic violence between methamphetamine users, patients with psychiatric disorders, and healthy people.

METHODS

In this analytical cross-sectional study, methamphetamine users (n=30) and patients with psychiatric disorders (n=30) were women whose husbands were hospitalized during 2014 in Shafa Psychiatric Hospital in Guilan. Diagnosis was done with DSMIV-TR. Healthy people (n=60) were women whose husbands had no primary or drug induced psychiatric disorder or addiction. CTS-2 test was used to evaluate violence.

RESULTS

The frequency of psychological, physical and sexual violence in the groups suffering from psychiatric disease and methamphetamine users was higher than the healthy group (P=0.001). We observed a direct correlation between the mean of psychological and physical violence in the three groups (r=0.9, P=0.001), (r=0.7, P=0.0001) and (r=0.53, P=0.005), respectively. Direct correlation between the psychological and physical violence was only observed in the healthy group (r=0.8, P=0.007).

CONCLUSION

The results showed that methamphetamine users such as psychiatric patients are at increased risk of violence. Domestic violence screening of these patients is necessary. It seems that this substance is a new source of increasing domestic violence with more undesirable outcomes in Iran.

Making Sense of: Sensitization in Schizophrenia

Sensitization is defined as a process whereby repeated intermittent exposure to a given stimulus results in an enhanced response at subsequent exposures. Next to robust findings of an increased dopamine synthesis capacity in schizophrenia, empirical data and neuroimaging studies support the notion that the mesolimbic dopamine system of patients with schizophrenia is more reactive compared with healthy controls. These studies led to the conceptualization of schizophrenia as a state of endogenous sensitization, as stronger behavioral response and increased dopamine release after amphetamine administration or exposure to stress have been observed in patients with schizophrenia. These findings have also been integrated into the neurodevelopmental model of the disorder, which assumes that vulnerable neuronal circuits undergo progressive changes during puberty and young adulthood that lead to manifest psychosis. Rodent and human studies have made an attempt to identify the exact mechanisms of sensitization of the dopaminergic system and its association with psychosis. Doing so, several epigenetic and molecular alterations associated with dopamine release, neuroplasticity, and cellular energy metabolism have been discovered. Future research aims at targeting these key proteins associated with sensitization in schizophrenia to enhance the knowledge of the pathophysiology of the illness and pave the way for an improved treatment or even prevention of this severe psychiatric disorder.

GABAergic mRNA expression is differentially expressed across the prelimbic and orbitofrontal cortices of rats sensitized to methamphetamine: Relevance to psychosis

Psychotic disorders, such as schizophrenia, are characterized by prevalent and persistent executive deficits that are believed to be the result of dysfunctional inhibitory gamma-aminobutyric acid (GABA) processing of the prefrontal cortex (PFC). Methamphetamine (METH) is a commonly used psychostimulant that can induce psychotic and cognitive symptoms that are indistinguishable to schizophrenia, suggesting that METH-induced psychosis may have a similar GABAergic profile of the PFC. As the PFC consists of multiple subregions, the aim of the current study was to investigate changes to GABAergic mRNA expression in the prelimbic (PRL) and orbitofrontal (OFC) cortices of the PFC in rats sensitized to repeated METH administration. Male Sprague Dawley rats underwent daily METH or saline injections for 7 days. Following 14 days of withdrawal, rats were challenged with acute METH administration, RNA was isolated from the PRL and OFC and quantitative PCR was used to compare the relative expression of GABA enzymes, transporters, metabolites and receptor subunits. GAD₆₇, GAD₆₅, GAT₁, GAT₃, VGAT and GABA_T mRNA expression were upregulated in the PRL. Ionotropic GABAA receptor subunits α1, α3, α5 and β2 were specifically upregulated in the OFC. These findings suggest that alterations to GABAergic mRNA expression following sensitization to METH are biologically dissociated between the OFC and PRL, suggesting that GABAergic gene expression is significantly altered following chronic METH exposure in a brain-region and GABA-specific manner. These changes may lead to profound consequences on central inhibitory mechanisms of localized regions of the PFC and may underpin common behavioral phenotypes seen across psychotic disorders.

Psychosis associated with acute recreational drug toxicity: a European case series

BACKGROUND

Psychosis can be associated with acute recreational drug and novel psychoactive substance (NPS) toxicity. However, there is limited data available on how common this is and which drugs are most frequently implicated. We describe a European case series of psychosis associated with acute recreational drug toxicity, and estimate the frequency of psychosis for different recreational drugs.

METHODS

The European Drug Emergencies Network (Euro-DEN) collects data on presentations to Emergency Departments (EDs) with acute recreational drug and NPS toxicity at 16 centres in ten countries. Euro-DEN data from October 2013 through September 2014 was retrospectively searched, and cases with psychosis were included. The proportion of cases with psychosis per drug was calculated in the searched Euro-DEN dataset.

RESULTS

Psychosis was present in 348 (6.3 %) of 5529 cases. The median (interquartile range) age was 29 (24-38) years, 276 (79.3 %) were male and 114 (32.8 %) were admitted to psychiatric ward. The drugs most commonly reported were cannabis in 90 (25.9 %) cases, amphetamine in 87 (25.0 %) and cocaine in 56 (16.1 %). More than one drug was taken in 189 (54.3 %) cases. Psychosis was frequent in those ED presentations involving tryptamines (4/7; 57.1 %), methylenedioxypyrovalerone (MDPV) (6/22; 27.3 %), methylphenidate (6/26; 23.1 %), lysergic acid diethylamide (LSD) (18/86; 20.9 %), psilocybe mushrooms (3/16; 18.8 %), synthetic cannabinoid receptor agonists (4/26; 15.4 %) and amphetamine (87/593; 14.7 %), but less common in those involving mephedrone (14/245; 5.7 %), methylenedioxymethamphetamine (MDMA) (20/461; 4.3 %) and methedrone (3/92; 3.3 %). Amphetamine was the most frequent drug associated with psychosis when only one agent was reported, with psychosis occurring in 32.4 % of these presentations.

CONCLUSION

The frequency of psychosis in acute recreational drug toxicity varies considerably between drugs, but is a major problem in amphetamine poisoning. In rapidly changing drug markets and patterns of use, the Euro-DEN sentinel network contributes to measuring the scale of drug-related harms in Europe beyond other more established indicators.

Factors affecting severity of positive and negative symptoms of psychosis in a polysubstance using population with psychostimulant dependence

Approximately half of psychostimulant users experience psychotic symptoms, which include both positive and negative symptoms. Prior reports have exclusively used positive symptoms to characterize psychostimulant associated psychosis. Symptoms vary dramatically in severity, though most investigations categorize psychosis as a dichotomous occurrence. To explore the association between different substances of abuse and the severity of psychotic symptoms, we investigated 171 individuals meeting DSM-IV-TR criteria for psychostimulant (cocaine or methamphetamine) dependence in an observational cross-sectional study. Participants were predominantly male (72.5%), recruited from a socially disadvantaged neighborhood in Vancouver, Canada, with a mean age of 45.5(±8.8) years. Of the total sample, 85% were dependent on cocaine, and 28.1% were dependent on methamphetamine. Participants had a median total PANSS score of 63, ranging from 37 to 111. Demographic information, current substance use and early substance exposure were used to predict positive and negative psychotic symptom severity in linear regression models. Increased severity of positive psychotic symptoms was significantly related to greater methamphetamine and marijuana use in the past 28 days, and methadone-abstinence. Negative symptom severity was related to increased opioid use in the past 28 days. There was no overlap between predictors of positive and negative symptom severity.

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.

Does elevated peripheral benzodiazepine receptor gene expression relate to cognitive deficits in methamphetamine dependence?

BACKGROUND

Methamphetamine (METH) is a neurotoxin and psychostimulant drug with potent effects on the central nervous system. With chronic METH administration, an inflammatory glial response is observed as a result of METH-induced neurotoxicity. One inflammatory marker is the peripheral benzodiazepine receptor (PBR).

OBJECTIVE

The purpose of the present study was to determine whether PBR expression is changed in METH dependence and whether the changes relate to cognitive deficits.

METHODS

Reverse transcriptase-polymerase chain reaction was used to investigate PBR gene expression in blood samples taken from 14 male subjects with METH dependence and 14 controls.

RESULTS

The results showed a significant increase in PBR gene expression in METH dependence, suggestive of a systemic inflammatory response. The increase remained elevated for more than 1 year following abstinence from METH use, but eventually returned to normal. Subjects with elevated PBR also exhibited a deficit in one domain of the Wisconsin Card Sorting Test.

CONCLUSION

The results suggest that systemic inflammatory effects can be associated with chronic METH abuse, and this may relate to the cognitive deficits seen in METH dependence. Copyright © 2016 John Wiley & Sons, Ltd.

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.

Altered social cognition in male BDNF heterozygous mice and following chronic methamphetamine exposure

Growing clinical evidence suggests that persistent psychosis which occurs in methamphetamine users is closely related to schizophrenia. However, preclinical studies in animal models have focussed on psychosis-related behaviours following methamphetamine, and less work has been done to assess endophenotypes relevant to other deficits observed in schizophrenia. Altered social behaviour is a feature of both the negative symptoms and cognitive deficits in schizophrenia, and significantly impacts patient functioning. We recently found that brain-derived neurotrophic factor (BDNF) heterozygous mice show disrupted sensitization to methamphetamine, supporting other work suggesting an important role of this neurotrophin in the pathophysiology of psychosis and the neuronal response to stimulant drugs. In the current study, we assessed social and cognitive behaviours in methamphetamine-treated BDNF heterozygous mice and wildtype littermate controls. Following chronic methamphetamine exposure male wildtype mice showed a 50% reduction in social novelty preference. Vehicle-treated male BDNF heterozygous mice showed a similar impairment in social novelty preference, with a trend for no further disruption by methamphetamine exposure. Female mice were unaffected in this task, and no groups showed any changes in sociability or short-term spatial memory. These findings suggest that chronic methamphetamine alters behaviour relevant to disruption of social cognition in schizophrenia, supporting other studies which demonstrate a close resemblance between persistent methamphetamine psychosis and schizophrenia. Together these findings suggest that dynamic regulation of BDNF signalling is necessary to mediate the effects of methamphetamine on behaviours relevant to schizophrenia.

Clinical features, course and treatment of methamphetamine-induced psychosis in psychiatric inpatients

BACKGROUND

Over the past few years, methamphetamine-induced psychosis (MIP) has increased in Iran, accounting for a significant percentage of psychiatry hospital admissions. The present study was conducted with an aim to investigate clinical symptoms, and course and treatment methods of MIP inpatients in Shafa Psychiatry Hospital in northern Iran.

METHODS

Participants were 152 MIP inpatients. Brief Psychiatric Rating Scale (BPRS) subscales of suspiciousness, unusual thought content; hallucinations and hostility were used to measure psychiatric symptoms. Data regarding suicide and homicide and violence were also obtained through interviews with the inpatients and their family. Based on their lengths of recovery time, the inpatients were categorized into 3 clinical groups. These inpatients received their usual treatments and were monitored for their psychiatric symptoms and clinical course of illness. The data were analyzed by descriptive statistics.

RESULTS

The most frequent psychiatric symptoms were violence (75.6 %), intimate partner violence (61.2 %), delusions of persecution (85.5 %), delusions of reference (38.5 %), delusions of grandiosity (32.9 %), delusions of infidelity (30.2 %), auditory hallucinations (51.3 %), visual hallucinations (18.4 %), suicidal thoughts (14.5 %), homicidal thoughts (3.9 %), suicide attempts (10.5 %) and homicide attempts (0.7 %). Recovery from psychotic symptoms in 31.6 % of the inpatients took more than one month. 46.1% of the inpatients were treated with Risperidone and 37.5 % with Olanzapine. Persecutory delusion and auditory hallucination were the most frequent persistent psychotic symptoms. 20.8 % of the inpatients with duration of psychosis more than one month were treated with electroconvulsive therapy (ECT) along with antipsychotics.

CONCLUSION

All forms of violence are highly frequent in MIP inpatients. Our finding agrees with many other studies suggesting that recovery from MIP can take more than a month. Initial promising findings were found regarding the efficacy of Electroconvulsive therapy in MIP patients.

GABAergic mRNA expression is upregulated in the prefrontal cortex of rats sensitized to methamphetamine

Inhibitory gamma-aminobutyric acid (GABA)-mediated neurotransmission plays an important role in the regulation of the prefrontal cortex (PFC), with increasing evidence suggesting that dysfunctional GABAergic processing of the PFC may underlie certain deficits reported across psychotic disorders. Methamphetamine (METH) is a psychostimulant that induces chronic psychosis in a subset of users, with repeat administration producing a progressively increased vulnerability to psychotic relapse following subsequent drug administration (sensitization). The aim here was to investigate changes to GABAergic mRNA expression in the PFC of rats sensitized to METH using quantitative polymerase chain reaction (qPCR). Male Sprague-Dawley rats (n=12) underwent repeated methamphetamine (intraperitoneal (i.p.) or saline injections for 7 days. Following 14 days of withdrawal, rats were challenged with acute methamphetamine (1mg/kg i.p.) and RNA was isolated from the PFC to compare the relative mRNA expression of a range of GABA enzymes, transporters and receptors subunits. METH challenge resulted in a significant sensitized behavioral (locomotor) response in METH pre-treated animals compared with saline pre-treated controls. The mRNAs of transporters (GAT1 and GAT3), ionotropic GABAA receptor subunits (α3 and β1), together with the metabotropic GABAB1 receptor, were upregulated in the PFC of sensitized rats compared with saline controls. These findings indicate that GABAergic mRNA expression is significantly altered at the pre and postsynaptic level following sensitization to METH, with sensitization resulting in the transcriptional upregulation of several inhibitory genes. These changes likely have significant consequences on GABA-mediated neurotransmission in the PFC and may underlie certain symptoms conserved across psychotic disorders, such as executive dysfunction.

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.

Chronic methamphetamine treatment reduces the expression of synaptic plasticity genes and changes their DNA methylation status in the mouse brain

Methamphetamine (METH) is a highly addictive psychostimulant that may cause long-lasting synaptic dysfunction and abnormal gene expression. We aimed to explore the differential expression of synaptic plasticity genes in chronic METH-treated mouse brain. We used the RT(2) Profiler PCR Array and the real-time quantitative PCR to characterize differentially expressed synaptic plasticity genes in the frontal cortex and the hippocampus of chronic METH-treated mice compared with normal saline-treated mice. We further used pyrosequencing to assess DNA methylation changes in the CpG region of the five immediate early genes (IEGs) in chronic METH-treated mouse brain. We detected six downregulated genes in the frontal cortex and the hippocampus of chronic METH-treated mice, including five IEGs (Arc, Egr2, Fos, Klf10, and Nr4a1) and one neuronal receptor gene (Grm1), compared with normal saline-treated group, but only four genes (Arc, Egr2, Fos, and Nr4a1) were confirmed to be different. Furthermore, we found several CpG sites of the Arc and the Fos that had significant changes in DNA methylation status in the frontal cortex of chronic METH-treated mice, while the klf10 and the Nr4a1 that had significant changes in the hippocampus. Our results show that chronic administration of METH may lead to significant downregulation of the IEGs expression in both the frontal cortex and the hippocampus, which may partly account for the molecular mechanism of the action of METH. Furthermore, the changes in DNA methylation status of the IEGs in the brain indicate that an epigenetic mechanism-dependent transcriptional regulation may contribute to METH addiction, which warrants additional study.

Differential patterns of blood oxygenation in the prefrontal cortex between patients with methamphetamine-induced psychosis and schizophrenia

Despite some slight differences in symptomatology, differential diagnosis of methamphetamine-induced psychosis (MAP) versus schizophrenia can be challenging because both disorders present a large overlap in their clinical symptoms. However, a recent study has shown that near-infrared spectroscopy (NIRS) performed during a cognitive task can be a powerful tool to differentiate between these two disorders. Here, we evaluated verbal fluency task performance during NIRS in 15 patients diagnosed with MAP and 19 with schizophrenia matched for age and sex. We used prefrontal probes and a 24-channel NIRS machine to measure the relative concentrations of oxyhaemoglobin every 0.1 s during the task. For each patient, the neurocognitive function and clinical psychopathology were evaluated using the Positive and Negative Symptom Scale (PANSS), and the Brief Assessment of Cognition in Schizophrenia (BACS). Oxyhaemoglobin changes in the prefrontal cortex were significantly higher in the MAP group compared to those in the schizophrenia group, particularly in the right dorsolateral prefrontal cortex. In contrast, we found no significant difference in PANSS and BACS scores. Our findings suggest that NIRS measurement could be applied to differentiate patients with MAP from those with schizophrenia, even in cases where clinical symptoms are similar.

Persistence of psychotic symptoms as an indicator of cognitive impairment in methamphetamine users

BACKGROUND

Prolonged exposure to methamphetamine (meth) has neurotoxic effects and impairs neurocognitive functions. This study aims to ascertain whether meth users who experience persistent psychosis suffer more severe cognitive impairment than those not experiencing persistent psychosis.

METHODS

This cross-sectional study includes 252 participants: 25 meth users without psychosis (METH-P), 50 with brief psychosis (METH+BP), and 56 with persistent psychosis (METH+PP), as well as 54 patients with schizophrenia and 67 healthy controls. The neurocognitive function and clinical psychopathology of each patient were evaluated with the Brief Assessment of Cognition in Schizophrenia (BACS) and the Brief Psychiatric Rating Scale (BPRS), respectively.

RESULTS

All cognitive domains evaluated with BACS (verbal memory, working memory, motor speed, verbal fluency, attention and processing speed, executive function, and composite scores) in METH+PP patients were similar to those in the schizophrenia patients and were worse than those in METH-P, METH+BP, and the healthy control subjects. Furthermore, cognitive functioning in meth users that did not experience persistent psychosis showed no statistically significant difference compared with the healthy control subjects. Among the meth users in this study, the negative symptom scores in the BPRS correlated to cognitive performance on the BACS, with the exception of motor speed.

CONCLUSIONS

Meth users display heterogeneity in their psychotic symptoms and cognitive profiles. Therefore, persistent psychotic symptoms may denote a risk for cognitive decline among meth users. Further longitudinal studies should be performed in the future to clarify the causal relationship between cognitive deficits and the development of persistent psychosis.

Differentiating between the course of illness in bipolar 1 and chronic-psychotic heroin-dependent patients at their first agonist opioid treatment

In an effort to inquiry the "self-medication hypothesis" in heroin-dependent patients suffering from chronic psychosis and bipolar disorder, a naturalistic comparative cohort study was designed with the aim of comparing, according to the presence of dual diagnosis, the clinical characteristics of heroin-dependent patients presenting for their first agonist opioid treatment. The main finding was that addictive (heroin) illness was more severe in bipolar 1 patients and less severe in chronic psychotic patients when compared with heroin-dependent patients without dual diagnoses. In the case of chronic psychotic patients, these differences do not allow us to exclude a therapeutic heroin use, at least at the beginning of their toxicomanic career, with limited progression of their addictive disease. This occurrence seems to be excluded for bipolar 1 heroin-dependent patients, who come to their first agonist opioid treatment with a more severe addictive disease.

Methamphetamine-induced sensitization is associated with alterations to the proteome of the prefrontal cortex: implications for the maintenance of psychotic disorders

Repeat administration of psychostimulants, such as methamphetamine, produces a progressive increase in locomotor activity (behavioral sensitization) in rodents that is believed to represent the underlying neurochemical changes driving psychoses. Alterations to the prefrontal cortex (PFC) are suggested to mediate the etiology and maintenance of these behavioral changes. As such, the aim of the current study was to investigate changes to protein expression in the PFC in male rats sensitized to methamphetamine using quantitative label-free shotgun proteomics. A methamphetamine challenge resulted in a significant sensitized locomotor response in methamphetamine pretreated animals compared to saline controls. Proteomic analysis revealed 96 proteins that were differentially expressed in the PFC of methamphetamine treated rats, with 20% of these being previously implicated in the neurobiology of schizophrenia in the PFC. We identified multiple biological functions in the PFC that appear to be commonly altered across methamphetamine-induced sensitization and schizophrenia, and these include synaptic regulation, protein phosphatase signaling, mitochondrial function, and alterations to the inhibitory GABAergic network. These changes could inform how alterations to the PFC could underlie the cognitive and behavioral dysfunction commonly seen across psychoses and places such biological changes as potential mediators in the maintenance of psychosis vulnerability.

Serotonin in the ventral hippocampus modulates anxiety-like behavior during amphetamine withdrawal

Withdrawal from amphetamine is associated with increased anxiety and sensitivity to stressors which are thought to contribute to relapse. Rats undergoing amphetamine withdrawal fail to exhibit stress-induced increases in serotonin (5-HT) release in the ventral hippocampus and show heightened anxiety-like behaviors. Therefore, we tested the hypothesis that reducing 5-HT levels in the ventral hippocampus is a causal mechanism in increasing anxiety-like behaviors during amphetamine withdrawal. First, we tested whether reducing 5-HT levels in the ventral hippocampus directly increases anxiety behavior. Male rats were bilaterally infused with 5,7-dihydroxytryptamine (5,7-DHT) into the ventral hippocampus, which produced a 83% decrease in ventral hippocampus 5-HT content, and were tested on the elevated plus maze (EPM) for anxiety-like behavior. Reducing ventral hippocampus 5-HT levels decreased the time spent in the open arms of the maze, suggesting that diminished ventral hippocampus 5-HT levels increases anxiety-like behavior. Next, we tested whether increasing 5-HT levels in the ventral hippocampus reverses anxiety behavior exhibited by rats undergoing amphetamine withdrawal. Rats were treated daily with either amphetamine (2.5-mg/kg, i.p.) or saline for 2weeks, and at 2weeks withdrawal, were infused with the selective serotonin reuptake inhibitor paroxetine (0.5μM) bilaterally into the ventral hippocampus and tested for anxiety-like behavior on the EPM. Rats pre-treated with amphetamine exhibited increased anxiety-like behavior on the EPM. This effect was reversed by ventral hippocampus infusion of paroxetine. Our results suggest that 5-HT levels in the ventral hippocampus are critical for regulating anxiety behavior. Increasing 5-HT levels during withdrawal may be an effective strategy for reducing anxiety-induced drug relapse.