Methamphetamine and cannabis are two widely used substances with possibly opposing effects on aspects of central nervous system functioning. Use of these substances is prevalent among people with HIV (PWH), though their combined effects on HIV-associated neurocognitive impairment (NCI) are unknown. Adverse effects of methamphetamine use on cognition are well documented. Cannabis may disturb cognition acutely, though its longer-term effects in PWH are not well understood. Our prior analysis of people without HIV (PWoH) found that cotemporaneous cannabis use was associated with better neurocognitive outcomes among methamphetamine users. The aim of this study was to assess how lifetime cannabis and methamphetamine use disorder relate to neurocognitive outcomes in PWH.

HIV-positive participants (n=472) were on average 45.6±11.5 years of age, male (86.4%), White (60.6%), and educated 13.9±2.5 years. Most participants were on ART (81.9%) and virally suppressed (70%). Participants were stratified by lifetime methamphetamine (M-/M+) and cannabis (C-/C+) DSM-IV abuse/dependence disorder into four groups: M-C- (n=187), M-C+ (n=68), M+C-, (n=82) and M+C+ (n=135) and completed a comprehensive neurobehavioral assessment. Demographically corrected T-scores and deficit scores were used for analyses. Group differences in global and domain NC performances (i.e., T-scores) were examined using multiple linear regression, holding constant covariates that were associated with study groups and/or cognition. Specifically, M+ participants displayed higher rates of Hepatitis C infection (p=.004), higher current depressive symptom scores (p<.001), and higher rates of detectable plasma HIV RNA (p=.014). Multiple logistic regression was used to test for group differences in probability of neurocognitive impairment (i.e., deficit scores>0.5), including the same covariates. Pooling data with a sample of HIV-negative participants (n=423), we used generalized linear mixed effect models to examine how neurocognitive performance and impairment profiles varied by methamphetamine and/or cannabis use group, HIV disease characteristics, and their interactions.

Compared to M+C+, M+C- performed worse on measures of executive functions (ß=-3.17), learning (ß=-3.95), memory (ß=-5.58), and working memory (ß=-4.05) and were more likely to be classified as impaired in the learning (OR=2.93), memory (OR=5.24), and working memory (OR=2.48) domains. M-C- performed better than M+C+ on measures of learning (ß=3.46) and memory (ß=5.19), but worse than M-C+ on measures of executive functions (ß=-3.90), learning (ß=-3.32), memory (ß=-3.38), and working memory (ß=-3.38). Generalized linear mixed effect models indicate that detectable plasma HIV RNA (ß=-1.85) and low nadir CD4 T-cell counts (nadir CD4<200; ß=-1.07) were associated with worse neurocognitive performance, and these effects did not differ in size or direction by substance use group.

In PWH, lifetime methamphetamine use disorder and both current and legacy markers of HIV disease severity are associated with worse neurocognitive outcomes. Cannabis use disorder does not appear to exacerbate methamphetamine-related deficits in PWH. Instead, results are consistent with findings from preclinical studies that cannabis use may protect against methamphetamine’s deleterious effects. Profile analysis models showed that participants with a history of cannabis use disorder display better overall neurocognitive performance than comparison (M-C-) participants. Mechanisms underlying a potential protective effect of cannabis may be elucidated by examining the temporal relationship between cannabis and methamphetamine consumption and neurocognitive performance.

Methamphetamine and cannabis are two widely used, and frequently co-used, substances with possibly opposing effects on the central nervous system. Evidence of neurocognitive deficits related to use is robust for methamphetamine and mixed for cannabis. Findings regarding their combined use are inconclusive. We aimed to compare neurocognitive performance in people with lifetime cannabis or methamphetamine use disorder diagnoses, or both, relative to people without substance use disorders.

423 (71.9% male, aged 44.6 ± 14.2 years) participants, stratified by presence or absence of lifetime methamphetamine (M−/M+) and/or cannabis (C−/C+) DSM-IV abuse/dependence, completed a comprehensive neuropsychological, substance use, and psychiatric assessment. Neurocognitive domain T-scores and impairment rates were examined using multiple linear and binomial regression, respectively, controlling for covariates that may impact cognition.

Globally, M+C+ performed worse than M−C− but better than M+C−. M+C+ outperformed M+C− on measures of verbal fluency, information processing speed, learning, memory, and working memory. M−C+ did not display lower performance than M−C− globally or on any domain measures, and M−C+ even performed better than M−C− on measures of learning, memory, and working memory.

Our findings are consistent with prior work showing that methamphetamine use confers risk for worse neurocognitive outcomes, and that cannabis use does not appear to exacerbate and may even reduce this risk. People with a history of cannabis use disorders performed similarly to our nonsubstance using comparison group and outperformed them in some domains. These findings warrant further investigation as to whether cannabis use may ameliorate methamphetamine neurotoxicity.

Over 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.

The purpose of this review is to find out if olanzapine is better than other antipsychotics in treating methamphetamine-induced psychosis.

PubMed, 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.

The 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.

Olanzapine 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.

No significant relationships.

The adolescent brain may be susceptible to the influences of illicit drug use. While compensatory network reorganization is a unique developmental characteristic that may restore several brain disorders, its association with methamphetamine (MA) use-induced damage during adolescence is unclear.

Using independent component (IC) analysis on structural magnetic resonance imaging data, spatially ICs described as morphometric networks were extracted to examine the effects of MA use on gray matter (GM) volumes and network module connectivity in adolescents (51 MA users v. 60 controls) and adults (54 MA users v. 60 controls).

MA use was related to significant GM volume reductions in the default mode, cognitive control, salience, limbic, sensory and visual network modules in adolescents. GM volumes were also reduced in the limbic and visual network modules of the adult MA group as compared to the adult control group. Differential patterns of structural connectivity between the basal ganglia (BG) and network modules were found between the adolescent and adult MA groups. Specifically, adult MA users exhibited significantly reduced connectivity of the BG with the default network modules compared to control adults, while adolescent MA users, despite the greater extent of network GM volume reductions, did not show alterations in network connectivity relative to control adolescents.

Our findings suggest the potential of compensatory network reorganization in adolescent brains in response to MA use. The developmental characteristic to compensate for MA-induced brain damage can be considered as an age-specific therapeutic target for adolescent MA users.

This study examined the association between methamphetamine use and psychotic symptoms in a New Zealand general population birth cohort (n = 1265 at birth).

At age 18, 21, 25, 30, and 35, participants reported on their methamphetamine use and psychotic symptoms in the period since the previous interview. Generalized estimating equations modelled the association between methamphetamine use and psychotic symptoms (percentage reporting any symptom, and number of symptoms per participant). Confounding factors included childhood individual characteristics, family socioeconomic circumstances and family functioning. Long term effects of methamphetamine use on psychotic symptoms were assessed by comparing the incidence of psychotic symptoms at age 30–35 for those with and without a history of methamphetamine use prior to age 30.

After adjusting for confounding factors and time-varying covariate factors including concurrent cannabis use, methamphetamine use was associated with a modest increase in psychosis risk over five waves of data (adjusted odds ratio (OR) 1.33, 95% confidence interval (CI) 1.03–1.72 for the percentage measure; and IRR 1.24, 95% CI 1.02–1.50 for the symptom count measure). The increased risk of psychotic symptoms was concentrated among participants who had used at least weekly at any point (adjusted OR 2.85, 95% CI 1.21–6.69). Use of methamphetamine less than weekly was not associated with increased psychosis risk. We found no evidence for a persistent vulnerability to psychosis in the absence of continuing methamphetamine use.

Methamphetamine use is associated with increased risk of psychotic symptoms in the general population. Increased risk is chiefly confined to people who ever used regularly (at least weekly), and recently.

Methamphetamine has been consistently associated with positive psychotic symptoms, but little is known about whether the reverse also occurs.

This study determined whether the relationship between methamphetamine use and positive psychotic symptoms is bidirectional over 12 months. The impact of lifetime psychotic disorders and methamphetamine dependence on these relationships was also examined.

A total of 201 regular (at least monthly) primary methamphetamine users were recruited from free needle and syringe programmes in three Australian cities. Data on the frequency of methamphetamine and other drug use (from Timeline Followback inteviews) and the severity of positive psychotic symptoms (using the Brief Psychiatric Rating Scale) in the past 2 weeks were collected in 12 contiguous monthly face-to-face interviews (mean of 9.14/11 (s.d. = 3.16) follow-ups completed). Diagnoses were derived using the Psychiatric Research Interview for DSM-IV Substance and Mental Disorders.

The mean age of participants was 31.71 years (s.d. = 8.19) and 39% (n = 77) were women. At baseline 55% (n = 110) were dependent on methamphetamine and 51% (n = 102) had a lifetime psychotic disorder. Cross-lagged dynamic panel models found a significant bidirectional relationship between psychotic symptoms and methamphetamine use (Comparative Fit Index (CFI) = 0.94, standardised root mean square residual (SRMR) = 0.05, root mean square error of approximation (RMSEA) = 0.05, 95% CI 0.04–0.06). The magnitude of the relationship in each direction was similar, and the presence of methamphetamine dependence or a lifetime psychotic disorder did not have an impact on results.

A dynamic, bidirectional relationship between methamphetamine and psychotic symptoms of similar magnitude in each direction was found over 1 year. This suggests integrated treatments that target methamphetamine, psychotic symptoms and their interrelationship may be of most benefit.

Methamphetamine (MA) dependence contributes to neurotoxicity and neurocognitive deficits. Although combined alcohol and MA misuse is common, how alcohol consumption relates to neurocognitive performance among MA users remains unclear. We hypothesized that alcohol and MA use would synergistically diminish neurocognitive functioning, such that greater reported alcohol consumption would exert larger negative effects on neurocognition among MA-dependent individuals compared to MA-nonusing persons.

Eighty-seven MA-dependent (MA+) and 114 MA-nonusing (MA−) adults underwent neuropsychological and substance use assessments. Linear and logistic regressions examined the interaction between MA status and lifetime average drinks per drinking day on demographically corrected global neurocognitive T scores and impairment rates, controlling for recent alcohol use, lifetime cannabis use, WRAT reading performance, and lifetime depression.

MA+ displayed moderately higher rates of impairment and lower T scores compared to MA−. Lifetime alcohol use significantly interacted with MA status to predict global impairment (ORR = 0.70, p = .003) such that greater lifetime alcohol use increased likelihood of impairment in MA−, but decreased likelihood of impairment in MA+. Greater lifetime alcohol use predicted poorer global T scores among MA− (b = −0.44, p = .030) but not MA+ (b = 0.08, p = .586).

Contrary to expectations, greater lifetime alcohol use related to reduced risk of neurocognitive impairment among MA users. Findings are supported by prior research identifying neurobiological mechanisms by which alcohol may attenuate stimulant-driven vasoconstriction and brain thermotoxicity. Replication and examination of neurophysiologic mechanisms underlying alcohol use in the context of MA dependence are warranted to elucidate whether alcohol confers a degree of neuroprotection.

Glycine regulates glutamatergic neurotransmission, and several papers have reported the relationship between glycine and schizophrenia. The dysbindin-1 (DTNBP1: dystrobrevin-binding protein 1) gene is related to glutamatergic neurotransmission and has been found to be a strong candidate gene for schizophrenia. In this study, we clarified the relationship between dysbindin, glutamate, and glycine with in vivo microdialysis methods.

We measured extracellular glycine and glutamate levels in the striatum of sandy (sdy) mice using in vivo microdialysis methods. Sdy mice express no dysbindin protein owing to a deletion in the dysbindin-1 gene. In addition, we measured changes in those amino acids after methamphetamine (METH) administration.

The basal levels of extracellular glycine and glutamate in the striatum of sdy mice were elevated. These extracellular glutamate levels decreased gradually after METH administration and were not subsequently different from those of wild-type mice.

These results suggest that dysbindin might modulate glycine and glutamate release in vivo.