Methamphetamine-associated Psychosis Research Articles

The distinct functional brain network and its association with psychotic symptom severity in men with methamphetamine-associated psychosis

BackgroundIndividuals using methamphetamine (METH) may experience psychosis, which usually requires aggressive treatment. Studies of the neural correlates of METH-associated psychosis (MAP) have focused predominantly on the default mode network (DMN) and cognitive control networks. We hypothesize that METH use alters global functional connections in resting-state brain networks and that certain cross-network connections could be associated with psychosis.MethodsWe recruited 24 healthy controls (CRL) and 54 men with METH use disorder (MUD) who were then divided into 25 without psychosis (MNP) and 29 with MAP. Psychotic symptom severity was assessed using the Positive and Negative Syndrome Scale (PANSS), evaluating (1) large-scale alterations in regional-wise resting-state functional connectivity (rsFC) across 11 brain networks and (2) associations between rsFC and psychotic symptom severity.ResultsThe MUD group exhibited greater rsFC between the salience network (SN)-DMN, and subcortical network (SCN)-DMN compared to the CRL group. The MAP group exhibited decreased rsFC in the sensory/somatomotor network (SMN)-dorsal attention network (DAN), SMN-ventral attention network (VAN), SMN-SN, and SMN-auditory network (AN), whereas the MNP group exhibited increased rsFC in the SMN-DMN and the frontoparietal network (FPN)-DMN compared to CRL. Additionally, the MAP group exhibited decreased rsFC strength between the SMN-DMN, SMN-AN, SMN-FPN, and DMN-VAN compared to the MNP group. Furthermore, across the entire MUD group, the PANSS-Positive subscale was negatively correlated with the DMN-FPN and FPN-SMN, while the PANSS-Negative subscale was negatively correlated with the DMN-AN and SMN-SMN.ConclusionMUD is associated with altered global functional connectivity. In addition, the MAP group exhibits a different brain functional network compared to the MNP group.

Assessment of resting cerebral perfusion between methamphetamine-associated psychosis and schizophrenia through arterial spin labeling MRI.

The clinical manifestations of methamphetamine (METH)-associated psychosis (MAP) and acute paranoid schizophrenia (SCZ) are similar. This study aims to assess regional cerebral blood flow (rCBF) in individuals who use METH and in those with SCZ using the MRI arterial spin labeling (ASL) technique. We prospectively recruited 68 participants and divided them into four groups: MAP (N = 15), SCZ (N = 13), METH users with no psychosis (MNP; N = 22), and normal healthy controls (CRL; N = 18). We measured rCBF using an MRI three-dimensional pseudo-continuous ASL sequence. Clinical variables were assessed using the Positive and Negative Syndrome Scale (PANSS) and Brief Assessment of Cognition in Schizophrenia (BACS). Group-level rCBF differences were analyzed using a two-sample t-test. Decreased rCBF was found in the precuneus, premotor cortex, caudate nucleus, dorsolateral prefrontal cortex, and thalamus in the MNP group compared with the CRL group. The MAP group had significantly decreased rCBF in the precuneus, hippocampus, anterior insula, inferior temporal gyrus, inferior orbitofrontal gyrus, and superior occipital gyrus compared with the MNP group. Increased rCBF in the precuneus and premotor cortex was seen in the MAP group compared with the SCZ group. rCBF in the precuneus and premotor cortex significantly correlated negatively with the PANSS but correlated positively with BACS scores in the MAP and SCZ groups. METH exposure was associated with decreased rCBF in the precuneus and premotor cortex. Patients with MAP exhibited higher rCBF than those with SCZ, implying preserved insight and favorable outcomes. rCBF can therefore potentially serve as a diagnostic approach to differentiate patients with MAP from those with SCZ.

A Narrative Review of the Pathophysiology and Treatment of Methamphetamine-Associated Psychosis

A Narrative Review of the Pathophysiology and Treatment of Methamphetamine-Associated Psychosis

Neural basis of the attention bias during addiction stroop task in methamphetamine-dependent patients with and without a history of psychosis: an ERP study.

Attentional bias plays an important role in sustaining various types of drug addiction. No prior studies examined methamphetamine (MA)-associated psychosis (MAP) relationships between ERP time course and performance on an addiction Stroop task in MA abusers. The aim of the present study was to determine whether MA abusers with (MAP+) or without (MAP-) psychosis exhibit alterations of the ERP during the addiction Stroop task. Thirty-one healthy controls (CTRL), 14 MAP-, and 24 MAP+ participants were recruited and completed the addiction Stroop task during EEG recording using 32 electrodes. Group variations were compared on measures of behavioral task performance and event-related potentials (ERP) of performance monitoring (N200, P300, N450). The Barratt impulsiveness scores were analyzed to investigate correlations with ERP changes. MA-related word stimulus elicited a more negative N200 amplitude over left-anterior electrodes in MAP- abusers; furthermore, a positive association between the N200 amplitude and Barratt attentional scores and non-planning scores was observed, while no such differences were found in MAP+ abusers. There were no significant differences in reaction time (RT) and error rate between each group. This is the first study to examine psychosis relationships between ERP time course and performance on an addiction Stroop task in MA abusers with or without psychosis. These findings support the association between attentional bias measured by the MA addiction Stroop task and N200 component as well as indicate the possibility of using this cognitive task in combination with ERP technology to detect psychosis factors among abstinent MA abusers.

Application Prospect of Integrative Omics in Forensic Identification of Methamphetamine-Associated Psychosis.

The clinical symptoms and signs of methamphetamine-associated psychosis (MAP) and schizophrenia are highly similar, but the situation is completely different when MAP and schizophrenia patients need to be assessed for criminal responsibility after they comitted a harmful behavior. Therefore, the distinction between the two psychoses is very important in forensic psychiatry. At present, the identification of these two psychoses is mainly dependent on the corresponding criteria such as the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) and the Chinese Classification of Mental Disorders Version 3 (CCMD-3). It's challenging to diagnose and distinguish between the two in practical cases due to their similar clinical symptoms and the lack of effective objective indexes. Different from the limitations of single omics, integrative omics intergrates data from multiple dimensions and has been extensively studied in the field of schizophrenia and has achieved some preliminary results. In view of the correlation between MAP and schizophrenia and the potential application value of integrative omics, this paper proposes an integrative omics strategy for MAP pathogenesis and forensic identification, aiming to improve the further understanding of the relationship between the two psychoses and the corresponding pathogenesis. It also provides references for the future exploration of integrative omics in forensic precise identification and effective monitoring and early warning methods.

Olanzapine and its use for methamphetamine-induced psychosis

IntroductionOver time the prevalence of methamphetamine associated psychosis (MAP) has increased globally including Asia and Europe. Shoptaw et al looked at an RCT and concluded that olanzapine is superior to haloperidol in terms of tolerability and the side effect profile as it causes fewer extrapyramidal symptoms. Another study by Xue et al compared the efficacy of olanzapine and haloperidol and found that they had comparable effects but the onset time in the olanzapine group was significantly earlier than the haloperidol group. Srisurapanont et al analyzed 6 RCTs and concluded that quetiapine and olanzapine are probably superior than aripiprazole and risperidone.ObjectivesThe purpose of this review is to find out if olanzapine is better than other antipsychotics in treating methamphetamine-induced psychosis.MethodsPubMed, SCOPUS, and Web of Science literature databases were screened and filtered by using specific search terms, inclusion/exclusion criteria. Texts of the selected articles and trials were reviewed and the search terms generated a total of 248 results from the databases. After applying the criteria 200 citations were left and 15 papers were reviewed.ResultsThe literature review concluded that olanzapine can be used as an effective treatment for methamphetamine-induced psychosis. Olanzapine can help to reduce the psychotic symptoms in MAP with a quicker onset and lesser side effects.ConclusionsOlanzapine can help in the treatment of methamphetamine-associated psychosis and can be considered as the first-line therapy. Research is further needed with a higher pool of candidates in the future to compare the efficacy and tolerability of different typical and atypical antipsychotics.DisclosureNo significant relationships.

Abstract WP125: Methamphetamine Associated Psychosis In Acute Stroke

Introduction: Methamphetamine, an addictive stimulant, may lead to psychosis of which little is known about the impact in acute stroke. Despite its short half-life, we hypothesize that methamphetamine use in acute stroke is associated with the development of psychosis and extends hospital length of stay (LOS). Methods: Single-center retrospective analysis (2016-2019) of consecutive adult patients admitted for acute ischemic stroke, intracerebral hemorrhage (ICH), aneurysmal subarachnoid hemorrhage (SAH), and transient ischemic attack (TIA) with methamphetamine detected on urine drug screen and were compared to those who did not. Psychosis was defined as disturbed thoughts or perceptions with abnormal psychomotor behavior. Psychosis onset and duration, clinical characteristics, total hospitalization time and intensive care unit (ICU) LOS, as well as psychotic treatment interventions were documented. Results: 138 patients were admitted for acute cerebrovascular events (87 ischemic strokes, 40ICH, 7 SAH, 2 TIAs). 69 patients tested positive for methamphetamine (68% male; mean age 53(range 26-68)) and were compared to 69 who did not (65% male, mean age 64 (range 30-93).Despite no differences in having any psychiatric illness history, 25% (17/69) of methamphetamine users experienced psychosis compared to only 3% (2/69) who did not test positive (p <0.0002). Although there was no statistical difference in hospital LOS (3.6 days in methamphetamine positive versus 2.9 days ( p =.113)), substance use abusers had significantly longer ICU stays (48 hours versus 24 hours; p =.006). NIHSS and ICH Scores were not statistically different between those who tested positive or negative for methamphetamine. Conclusions: Methamphetamine use is strongly associated with developing psychosis and when present, leads to longer ICU stay.

Common gray matter loss in the frontal cortex in patients with methamphetamine-associated psychosis and schizophrenia

Background and hypothesisMethamphetamine (MA)-associated psychosis has become a public concern. However, its mechanism is not clear. Investigating similarities and differences between MA-associated psychosis and schizophrenia in brain alterations would be informative for neuropathology. Study designThis study compared gray matter volumes of the brain across four participant groups: healthy controls (HC, n = 53), MA users without psychosis (MA, n = 22), patients with MA-associated psychosis (MAP, n = 34) and patients with schizophrenia (SCZ, n = 33). Clinical predictors of brain alterations, as well as association of brain alterations with psychotic symptoms and attention impairment were further investigated. Study resultsCompared with the HC, the MAP and the SCZ showed similar gray matter reductions in the frontal cortex, particularly in prefrontal areas. Moreover, a stepwise extension of gray matter reductions was exhibited across the MA – MAP – SCZ. Duration of abstinence was associated with regional volumetric recovery in the MAP, while this amendment in brain morphometry was not accompanied with symptom’s remission. Illness duration of psychosis was among the predictive factors of regional gray matter reductions in both psychotic groups. Volume reductions were found to be associated with attention impairment in the SCZ, while this association was reversed in the MAP in frontal cortex. ConclusionsThis study suggested MA-associated psychosis and schizophrenia had common neuropathology in cognitive-related frontal cortices. A continuum of neuropathology between MA use and schizophrenia was tentatively implicated. Illness progressions and glial repairments could both play roles in neuropathological changes in MA-associated psychosis.

Pharmacotherapy treatment of stimulant use disorder.

Stimulant use disorder (SUD) is a public health problem in the United States that is associated with increased morbidity and mortality. Psychosocial interventions, such as cognitive behavioral therapy and contingency management, are the main treatment modality for SUDs and no pharmacotherapy is currently FDA approved for this indication. Although some medications show promising data for the treatment of SUD, the evidence remains inconsistent, and the clinical application is limited due to the heterogenicity of the population and the lack of studies in patients with various comorbidities. Selection of pharmacotherapy treatment for methamphetamine intoxication, persistent methamphetamine-associated psychosis with methamphetamine use disorder, and cocaine use disorder in patients with co-occurring OUD are discussed in 3 patient cases.

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.

Brain dysfunction of methamphetamine-associated psychosis in resting state: Approaching schizophrenia and critical role of right superior temporal deficit.

Methamphetamine (MA)-associated psychosis (MAP) is highly debilitating and common among individuals who use the drug, yet the underlying neural mechanism is not clear. This study compared brain functions between patients with MAP and those with schizophrenia during resting state and investigated the effect of brain alteration on the association between MA use and psychosis in patients with MAP. Three groups, including 24 patients with MAP, 17 with schizophrenia in first-episode (SCZ) and 31 healthy controls (HCs), were included after receiving a resting-state functional MRI scan. The severity of psychosis was assessed with Positive and Negative Syndrome Scale (PANSS). Imaging data were analysed using regional homogeneity (ReHo) to measure individual's brain function. Compared with the HC subjects, the MAP and SCZ groups had significantly lower ReHo in the cortical regions including left postcentral cortex, right superior temporal gyrus and right rolandic operculum, while had higher ReHo in the left putamen, with brain dysfunctions being more pronounced in the SCZ group. Among the MAP subjects, a mediating effect of ReHo in the right superior temporal gyrus was found on the association between MA use frequency and PANSS positive score. MAP and schizophrenia had a common trend of brain alteration, with the dysfunction being more pronounced in schizophrenia. This finding implicated that MAP might be a condition with neuropathology approaching schizophrenia. The observed critical role of right superior temporal deficit between MA use and psychosis proposed a potential target for interventions.

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.

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.

Schizophrenia Polygenic Risk and Brain Structural Changes in Methamphetamine-Associated Psychosis in a South African Population.

BackgroundThe genetic architecture of psychotic disorders is complex, with hundreds of genetic risk loci contributing to a polygenic model of disease. Overlap in the genetics of psychotic disorders and brain measures has been found in European populations, but has not been explored in populations of African ancestry. The aim of this study was to determine whether a relationship exists between a schizophrenia-derived PRS and (i) methamphetamine associated psychosis (MAP), and (ii) brain structural measures, in a South African population.MethodsThe study sample consisted of three participant groups: 31 individuals with MAP, 48 with apsychotic methamphetamine dependence, and 49 healthy controls. Using PRSice, PRS was generated for each of the participants with GWAS summary statistics from the Psychiatric Genomics Consortium Schizophrenia working group (PGC-SCZ2) as the discovery dataset. Regression analyses were performed to determine associations of PRS, with diagnosis, whole brain, and regional gray and white matter measures.ResultsSchizophrenia-derived PRS did not significantly predict MAP diagnosis. After correction for multiple testing, no significant associations were found between PRS and brain measures across all groups.DiscussionThe lack of significant associations here may indicate that the study is underpowered, that brain volumes in MAP are due to factors other than polygenic risk for schizophrenia, or that PRS derived from a largely European discovery set has limited utility in individuals of African ancestry. Larger studies, that include diverse populations, and more nuanced brain measures, may help elucidate the relationship between schizophrenia-PRS, brain structural changes, and psychosis.ConclusionThis research presents the first PRS study to investigate shared genetic effects across psychotic disorders and brain structural measures in an African population. Ancestrally comparable discovery datasets may be useful for future African genetic research.

Randomized Controlled Trial of Paliperidone Extended Release Versus Risperidone for the Treatment of Methamphetamine-Associated Psychosis in Chinese Patients.

BackgroundThe efficacy or tolerability of paliperidone extended release (ER) in the treatment of methamphetamine (METH)-associated psychosis (MAP) is unknown. This study was designed to assess the tolerability and efficacy of paliperidone ER and risperidone for the treatment of MAP in China.MethodsThis 25-day randomized clinical trial involved 120 patients with acute MAP symptoms who were randomized to receive either paliperidone ER or risperidone from baseline to day 25 of an inpatient hospital stay. The primary outcome was changes in the severity of psychosis, which were assessed using the Positive and Negative Syndrome Scale (PANSS) total score changes from baseline to endpoint.ResultsOverall, 84% of the patients completed the entire study protocol. The PANSS total score, the Clinical Global Impressions-Severity of Illness scale (CGI-S) score, and a METH craving score assessed by a visual analog scale (VAS) showed statistically significant improvements from baseline for the patients in both groups (p < 0.01). The Simpson-Angus Scale (SAS) and the Barnes Akathisia Rating Scale (BARS) scores increased from baseline during treatment in both groups (p < 0.01); there were statistically significant differences between the treatment groups in the SAS scores (p < 0.01). Measures of hypermyotonia, salivation, and dizziness were significantly higher in the risperidone-treated patients than in the paliperidone ER-treated patients (all p < 0.05).ConclusionPaliperidone ER and risperidone had similar efficacy and were generally tolerable in the treatment of MAP; however, paliperidone ER had a more favorable adverse event profile than risperidone, particularly regarding extrapyramidal and prolactin-increasing effects.Clinical Trial RegistrationClinicalTrials.gov, identifier NCT01822730. Full date of first registration:03/28/2013.

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.

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

ObjectiveTo determine factors related to recent methamphetamine-associated psychosis (MAP) among individuals recently using methamphetamine (MA).DesignCross-sectional study carried out between July 2015 and June 2017.SettingFour mental health hospitals and one substance...

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

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. 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 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. 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.

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

BackgroundPositive 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. MethodParticipants (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. ResultsWe 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). ConclusionsA 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.

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.