A review of amphetamine extended release once-daily options for the management of attention-deficit hyperactivity disorder

INTRODUCTION

Amphetamine preparations are one of the two categories of stimulant medications approved for the treatment of attention deficit hyperactivity disorder (ADHD). Optimal treatment of ADHD aims to reduce core symptoms for as much of the waking hours as possible, leading to longer-acting delivery formats. In addition, the pediatric population commonly has difficulty swallowing pills and manufacturers have developed a variety of options to facilitate this concern. These include chewable tablets, capsules that may be sprinkled on soft food, liquids and transdermal patches.

AREAS COVERED

This article reviews the once-daily extended-release preparations currently available for amphetamine compounds, their pharmacodynamics, and common adverse effects.

EXPERT OPINION

There is an extensive evidence base supporting use of amphetamine preparations in the treatment of ADHD. Rapid onset of action and a favorable side effect profile make these widely used. The availability of once-daily extended-release chewable tablets, capsules that can be opened and sprinkled, and liquid formulations provides clinicians with multiple options to meet the specific needs of patients with difficulty swallowing whole pills.

Development of a novel rodent rapid serial visual presentation task reveals dissociable effects of stimulant versus nonstimulant treatments on attentional processes

The rapid serial visual presentation (RSVP) task and continuous performance tasks (CPT) are used to assess attentional impairments in patients with psychiatric and neurological conditions. This study developed a novel touchscreen task for rats based on the structure of a human RSVP task and used pharmacological manipulations to investigate their effects on different performance measures. Normal animals were trained to respond to a target image and withhold responding to distractor images presented within a continuous sequence. In a second version of the task, a false-alarm image was included, so performance could be assessed relative to two types of nontarget distractors. The effects of acute administration of stimulant and nonstimulant treatments for ADHD (amphetamine and atomoxetine) were tested in both tasks. Methylphenidate, ketamine, and nicotine were tested in the first task only. Amphetamine made animals more impulsive and decreased overall accuracy but increased accuracy when the target was presented early in the image sequence. Atomoxetine improved accuracy overall with a specific reduction in false-alarm responses and a shift in the attentional curve reflecting improved accuracy for targets later in the image sequence. However, atomoxetine also slowed responding and increased omissions. Ketamine, nicotine, and methylphenidate had no specific effects at the doses tested. These results suggest that stimulant versus nonstimulant treatments have different effects on attention and impulsive behaviour in this rat version of an RSVP task. These results also suggest that RSVP-like tasks have the potential to be used to study attention in rodents.

Protective effects of amphetamine and methylphenidate against dopaminergic neurotoxicants in SH-SY5Y cells

Full treatment of the second most common neurodegenerative disorder, Parkinson's disease (PD), is still considered an unmet need. As the psychostimulants, amphetamine (AMPH) and methylphenidate (MPH), were shown to be neuroprotective against stroke and other neuronal injury diseases, this study aimed to evaluate their neuroprotective potential against two dopaminergic neurotoxicants, 6-hydroxydopamine (6-OHDA) and paraquat (PQ), in differentiated human dopaminergic SH-SY5Y cells. Neither cytotoxicity nor mitochondrial membrane potential changes were seen following a 24-hour exposure to either therapeutic concentration of AMPH or MPH (0.001-10 μM). On the other hand, a 24-hour exposure to 6-OHDA (31.25-500 μM) or PQ (100-5000 μM) induced concentration-dependent mitochondrial dysfunction, assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, and lysosomal damage, evaluated by the neutral red uptake assay. The lethal concentrations 25 and 50 retrieved from the concentration-toxicity curves in the MTT assay were 99.9 µM and 133.6 µM for 6-OHDA, or 422 µM and 585.8 µM for PQ. Both toxicants caused mitochondrial membrane potential depolarization, but only 6-OHDA increased reactive oxygen species (ROS). Most importantly, PQ-induced toxicity was partially prevented by 1 μM of AMPH or MPH. Nonetheless, neither AMPH nor MPH could prevent 6-OHDA toxicity in this experimental model. According to these findings, AMPH and MPH may provide some neuroprotection against PQ-induced neurotoxicity, but further investigation is required to determine the exact mechanism underlying this protection.

Amphetamine-induced dopamine release in rat: Whole-brain spatiotemporal analysis with [11C]raclopride and positron emission tomography

Whole-brain mapping of drug effects are needed to understand the neural underpinnings of drug-related behaviors. Amphetamine administration is associated with robust increases in striatal dopamine (DA) release. Dopaminergic terminals are, however, present across several associative brain regions, which may contribute to behavioral effects of amphetamine. Yet the assessment of DA release has been restricted to a few brain regions of interest. The present work employed positron emission tomography (PET) with [11C]raclopride to investigate regional and temporal characteristics of amphetamine-induced DA release across twenty sessions in adult female Sprague Dawley rats. Amphetamine was injected intravenously (2 mg/kg) to cause displacement of [11C]raclopride binding from DA D2-like receptors, assessed using temporally sensitive pharmacokinetic PET model (lp-ntPET). We show amphetamine-induced [11C]raclopride displacement in the basal ganglia, and no changes following saline injections. Peak occupancy was highest in nucleus accumbens, followed by caudate-putamen and globus pallidus. Importantly, significant amphetamine-induced displacement was also observed in several extrastriatal regions, and specifically in thalamus, insula, orbitofrontal cortex, and secondary somatosensory area. For these, peak occupancy occurred later and was lower as compared to the striatum. Collectively, these findings demonstrate distinct amphetamine-induced DA responses across the brain, and that [11C]raclopride-PET can be employed to detect such spatiotemporal differences.

The anterior insula and its projection to amygdala nuclei modulate the abstinence-exacerbated expression of conditioned place preference

RATIONALE

Relapse into substance use is often triggered by exposure to drug-related environmental cues. The magnitude of drug seeking depends on the duration of abstinence, a phenomenon known as the incubation of drug craving. Clinical and preclinical research shows that the insular cortex is involved in substance use disorders and cue-induced drug seeking. However, the role of the insula on memory retrieval and motivational integration for cue-elicited drug seeking remains to be determined.

OBJECTIVES

We investigated the role of the anterior insular cortex (aIC) and its glutamatergic projection to amygdala nuclei (aIC-AMY) on the expression of conditioned place preference (CPP) during early and late abstinence.

METHODS

Male adult C57BL/6J mice underwent amphetamine-induced CPP, and their preference was tested following 1 or 14 days of abstinence. aIC and aIC-AMY functional role in CPP expression was assessed at both abstinence periods by employing optogenetic silencing and behavioral pharmacology.

RESULTS

Compared to a single day, an exacerbated preference for the amphetamine-paired context was observed after 14 days of abstinence. Photoinhibition of either aIC or aIC-AMY projection reduced CPP expression following late but not early abstinence. Similarly, the antagonism of aIC NMDA receptors reduced CPP expression after 14 days of abstinence but not 1 day.

CONCLUSIONS

These results suggest that aIC and its glutamatergic output to amygdala nuclei constitute critical neurobiological substrates mediating enhanced motivational cue reactivity during the incubation of amphetamine craving rather than contextual memory recall. Moreover, cortical NMDA receptor signaling may become sensitized during abstinence, ultimately modulating disproportioned drug seeking.

Structure-activity relationships for locomotor stimulant effects and monoamine transporter interactions of substituted amphetamines and cathinones

Substitutions to the phenethylamine structure give rise to numerous amphetamines and cathinones, contributing to an ever-growing number of abused novel psychoactive substances. Understanding how various substitutions affect the pharmacology of phenethylamines may help lawmakers and scientists predict the effects of newly emerging drugs. Here, we established structure-activity relationships for locomotor stimulant and monoamine transporter effects of 12 phenethylamines with combinations of para-chloro, β-keto, N-methyl, or N-ethyl additions. Automated photobeam analysis was used to evaluate effects of drugs on ambulatory activity in mice, whereas in vitro assays were used to determine activities at transporters for dopamine (DAT), norepinephrine (NET), and 5-HT (SERT) in rat brain synaptosomes. In mouse studies, all compounds stimulated locomotion, except for 4-chloro-N-ethylcathinone. Amphetamines were more potent stimulants than their β-keto counterparts, while para-chloro amphetamines tended to be more efficacious than unsubstituted amphetamines. Para-chloro compounds also produced lethality at doses on the ascending limbs of their locomotor dose-effect functions. The in vitro assays showed that all compounds inhibited uptake at DAT, NET, and SERT, with most compounds also acting as substrates (i.e., releasers) at these sites. Unsubstituted compounds displayed better potency at DAT and NET relative to SERT. Para-chloro substitution or increased N-alkyl chain length augmented relative potency at SERT, while combined para-chloro and N-ethyl substitutions reduced releasing effects at NET and DAT. These results demonstrate orderly SAR for locomotor stimulant effects, monoamine transporter activities, and lethality induced by phenethylamines. Importantly, 4-chloro compounds produce toxicity in mice that suggests serious risk to humans using these drugs in recreational contexts.

Quantitative determination of amphetamine-type stimulants in sewage and urine by hybrid monolithic column solid-phase microextraction coupled with UPLC-QTRAP MS/MS

A needle-solid-phase microextraction (SPME) method based on hybrid monolithic column (HMC) was proposed for simultaneous separation and extraction of seven amphetamine-type stimulants (ATSs) (amphetamine, methamphetamine, cathinone, methcathinone, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, and 3,4-methylenedioxyethylamphetamine), combining with ultra-performance liquid chromatography-triple quadrupole/linear ion trap mass spectrometer (UPLC-QTRAP MS/MS). Thiol functionalized HMC (T-HMC) showed high extraction efficiency and excellent elution results towards target analytes, among three kinds of single/bi-functionalized HMCs. Various parameters of SPME operation and analytical performance were investigated systematically. The adsorption mechanism of T-HMC to ATSs was also discussed and explained as a mixed mode of electrostatic and hydrophobic interactions. Under the optimum experimental conditions, the proposed T-HMC needle-SPME-UPLC-QTRAP MS/MS method was rapid and convenient with good accuracy, low sample consumption, high sensitivity and strong anti-interference ability. This method was successfully applied to quantitative determination of seven trace ATSs in complex sewage and urine samples. In view of abundant types of HMCs, the needle-SPME based on functional HMC also had the potential to selectively separating and enriching other tract new psychoactive substances in complex matrices, and could provide a reliable tool for drug monitoring, especially in applications for forensic analysis and drug abuse.

Post-translational mechanisms in psychostimulant-induced neurotransmitter efflux

The availability of monoamine neurotransmitters in the brain is under the control of dopamine, norepinephrine, and serotonin transporters expressed on the plasma membrane of monoaminergic neurons. By regulating transmitter levels these proteins mediate crucial functions including cognition, attention, and reward, and dysregulation of their activity is linked to mood and psychiatric disorders of these systems. Amphetamine-based transporter substrates stimulate non-exocytotic transmitter efflux that induces psychomotor stimulation, addiction, altered mood, hallucinations, and psychosis, thus constituting a major component of drug neurochemical and behavioral outcomes. Efflux is under the control of transporter post-translational modifications that synergize with other regulatory events, and this review will summarize our knowledge of these processes and their role in drug mechanisms.

Effects of congeners of amphetamine on the human heart

Central stimulatory and hallucinogenic drugs of abuse like amphetamine and most congeners of amphetamine can have cardiac harmful effects. These cardiac side effects can lead to morbidities and death. In this paper, we review current knowledge on the direct and indirect effects of these amphetamine congeners on the mammalian heart-more specifically, the isolated human heart muscle preparation. In detail, we address the question of whether and how these drugs affect cardiac contractility and their mechanisms of action. Based on this information, further research areas are defined, and further research efforts are proposed.

Methamphetamine spasm in the large caliber arteries-the severity is likely underestimated

This report describes two cases of rarely reported, severe large arterial vascular spasms seen on computed tomography images after methamphetamine abuse. Although the effects of methamphetamine on the central nervous system and smaller arteries are relatively well known, its effects on large caliber arteries are rarely discussed. We present two cases of severe large arterial multisegmented vasospasm, captured on contrast-enhanced computed tomography, several hours after methamphetamine abuse. One of the patients was discharged without apparent tissue loss or organ failure. The other developed severe heart failure, liver failure, and toe gangrene. The publication of the de-identified images has been approved by the VA Central California Health Care System's Research and Development Committee and Privacy Officer. Vascular surgeons and, perhaps, acute care physicians, who are usually aware of small arterial vasospastic conditions, should also be aware of this methamphetamine-induced large arterial finding, which can be quite dramatic in appearance on imaging.

Prescription psychostimulants for the treatment of amphetamine-type stimulant use disorder: A systematic review and meta-analysis of randomized placebo-controlled trials

BACKGROUND AND AIMS

There is currently no standard of care for pharmacological treatment of amphetamine-type stimulant (ATS) use disorder (ATSUD). This systematic review with meta-analysis (PROSPERO CRD42022354492) aimed to pool results from randomized placebo-controlled trials (RCTs) to evaluate efficacy and safety of prescription psychostimulants (PPs) for ATSUD.

METHODS

Major indexing sources and trial registries were searched to include records published before 29 August 2022. Eligible studies were RCTs evaluating efficacy and safety of PPs for ATSUD. Risk of bias (RoB) was assessed using the Cochrane RoB 2 tool. Risk ratio (RR) and risk difference were calculated for random-effect meta-analysis of dichotomous variables. Mean difference and standardized mean difference (SMD) were calculated for random-effect meta-analysis of continuous variables.

RESULTS

Ten RCTs (n = 561 participants) were included in the meta-analysis. Trials studied methylphenidate (n = 7), with daily doses of 54-180 mg, and dextroamphetamine (n = 3), with daily doses of 60-110 mg, for 2-24 weeks. PPs significantly decreased end-point craving [SMD  -0.29; 95% confidence interval (CI) = -0.55, -0.03], while such a decrease did not reach statistical significance for ATS use, as evaluated by urine analysis (UA) (RR = 0.93; 95% CI = 0.85-1.01). No effect was observed for self-reported ATS use, retention in treatment, dropout following adverse events, early-stage craving, withdrawal and depressive symptoms. In a sensitivity analysis, treatment was associated with a significant reduction in UA positive for ATS (RR = 0.89; 95% CI = 0.79-0.99) after removing studies with a high risk of bias. In subgroup analyses, methylphenidate and high doses of PPs were negatively associated with ATS use by UA, while higher doses of PPs and treatment duration (≥ 20 weeks) were positively associated with longer retention.

CONCLUSIONS

Among individuals with amphetamine-type stimulant use disorder, treatment with prescription psychostimulants may decrease ATS use and craving. While effect size is limited, it may increase with a higher dosage of medications.

Trends in Use of Telemedicine for Stimulant Initiation Among Children and Adults

OBJECTIVE

The authors sought to examine trends in stimulant initiation and follow-up care for attention-deficit hyperactivity disorder (ADHD) via telemedicine.

METHODS

This retrospective longitudinal study used national, deidentified commercial health insurance outpatient claims among children (ages 2-17 years; N=535,629) and adults (ages 18-64 years; N=2,116,160) from January 2019 through April 2022. Regression analyses were used to examine risk for stimulant initiation, whether initiation occurred via telemedicine or in-person care, and receipt of a follow-up visit.

RESULTS

The mean monthly adjusted number of stimulant initiations per 100,000 enrollees was similar for children before and during the COVID-19 pandemic (prepandemic, 57 initiations; during pandemic, 56 initiations) but increased for adults (prepandemic, 27 initiations; during pandemic, 33 initiations). Initiations via telemedicine peaked at 53%-57% in April 2020 and dropped to about 14% among children and 28% among adults in April 2022. Telemedicine initiations were significantly more common among psychiatrists than among other prescribers (OR=3.70, 95% CI=3.38-4.06 [children]; OR=3.02, 95% CI=2.87-3.17 [adults]) and less common for rural residents (OR=0.57, 95% CI=0.40-0.82 [children]; OR=0.75, 95% CI=0.61-0.92 [adults]). Follow-up care was significantly more common among individuals whose care was initiated via telemedicine than among those receiving in-person care (OR=1.09, 95% CI=1.00-1.19 [children]; OR=1.61, 95% CI=1.53-1.69 [adults]).

CONCLUSIONS

Many stimulant treatments were initiated via telemedicine. Proposed rules to prohibit controlled substance prescribing without an in-person evaluation would require significant changes in current practice, potentially limiting access to stimulant medications for ADHD.

Dopaminergic and glutamatergic models of psychosis show differential sensitivity to aripiprazole and a novel experimental compound modulating D2/5-HT receptor activity

Dopamine type 2 receptors (D2Rs) constitute the main molecular target in the pharmacotherapy of schizophrenia. However, the second and third generation of antipsychotics comprises multi-target ligands, also binding serotonin type 3 receptors (5-HT3Rs) and other receptor classes as well. Here, we examined two experimental compounds (marked compound K1697 and K1700) from the group of 1,4-di-substituted aromatic piperazines, previously described in the study of Juza et al., 2021, and compared them with the chosen reference antipsychotic, aripiprazole. Their efficacy against schizophrenia-like behavior was tested in two different models of psychosis in the rat, induced by acute administration of either amphetamine (1.5 mg/kg) or dizocilpine (0.1 mg/kg), reflecting the dopaminergic and glutamatergic hypotheses of schizophrenia. The two models exhibited broadly similar behavioral manifestations: hyperlocomotion, disrupted social behavior and impaired prepulse inhibition of the startle response. However, they differed in their treatment responses as hyperlocomotion and prepulse inhibition deficit in the dizocilpine model were resistant to antipsychotic treatment, unlike the amphetamine model. One of the experimental compounds, K1700, ameliorated all the observed schizophrenia-like behaviors in the amphetamine model with an efficacy comparable to or greater than aripiprazole. Whereas social impairments caused by dizocilpine were strongly suppressed by aripiprazole, K1700 was less efficient. Taken together, K1700 showed antipsychotic properties comparable to those of aripiprazole, although the efficacy of the two drugs differed in specific domains of behavior and was also model-dependent. Our present results highlight the differences in these two schizophrenia models and their responsiveness to pharmacotherapy, and confirm compound K1700 as a promising drug candidate.

Inefficacy of N-acetylcysteine in mitigating cue-induced amphetamine-seeking

Glutamatergic imbalances are characteristic of SUDs. Astrocytic and neuronal transporters help regulate glutamate homeostasis and disruptions in this homeostasis engender SUD. The cysteine-glutamate exchanger (xCT) is primarily localized on astrocytes and maintains glutamate concentrations. This process is disrupted by cocaine use, and the therapeutic N-acetylcysteine (NAC) lowers cue-induced relapse to cocaine by restoring xCT function. However, little research has shown how these effects extend to other psychostimulants, such as amphetamine (AMP). Here, we assessed xCT expression following relapse to AMP cues, and if NAC can attenuate relapse via changes to astrocyte and xCT expression. We administered NAC (100 mg/kg ip) daily during a 14-day abstinence period following AMP (0.1 mg/kg/infusion; 2 h sessions) self-administration. Relapse was tested following one (WD 1) or 14 days (WD 14) of withdrawal. The overall number of astrocytes was also quantified within the medial prefrontal cortex (mPFC) and nucleus accumbens (ACb). NAC failed to lower cue-induced AMP craving via cue-induced relapse and reinstatement testing. Cue-induced craving did not increase from WD 1 to WD 14. AMP-exposed rats had greater astrocyte counts in the mPFC and ACb when compared AMP-naïve rats. Repeated injection with NAC decreased xCT expression within the mPFC and ACb. Overall, these results suggest that NAC may be an ineffective treatment option for lowering cue-induced relapse to AMP. Further, the results suggest that stimulating xCT via NAC may not be an effective therapeutic approach for decreasing cue-seeking for AMP.

Bupropion for treatment of amphetamine-type stimulant use disorder: A systematic review and meta-analysis of placebo-controlled randomized clinical trials

BACKGROUND

This meta-analysis (PROSPERO-ID: CRD42022362962), pooled effect estimates of outcomes, from placebo-controlled randomized clinical trials (RCTs) examining bupropion efficacy and safety for amphetamine-type stimulant use disorder (ATSUD) treatment.

METHOD

Electronic databases were searched for records published to October 31st, 2022, including MEDLINE, CINAHL, PsycINFO, EBM Reviews, EMBASE, PubMed, Web of Science, trial registries. Inclusion criteria were RCTs comparing bupropion to placebo in ATSUD. Cochrane RoB2 tool and GRADE evidence certainty assessment were employed. Outcomes included amphetamine-type stimulant (ATS) use by urinalysis, retention in treatment, treatment adherence, ATS craving, addiction severity, depressive symptom severity, drop-out following adverse events (AEs), and serious AEs. Random-effect meta-analysis was conducted presenting standardized mean difference (SMD), risk ratio (RR), and risk difference (RD).

RESULTS

Eight RCTs (total N=1239 participants) were included. Bupropion compared to placebo was associated with reduced ATS use (RR: 0.90; 95% CI: 0.84, 0.96), end-of-treatment ATS craving (SMD: -0.38; 95%CI: -0.63, -0.13), and adherence (RR: 0.91; 95%CI: 0.84, 0.99). Subgroup analysis showed greater reduction in ATS use with longer trial duration (12 weeks) (RR: 0.85; 95%CI: 0.78, 0.93) and greater reduction in end-of-treatment ATS craving in studies with mixed ATS use frequency (SMD: -0.46; 95%CI: -0.70, -0.22) and male-only samples (SMD: -1.26; 95%CI: -1.87, -0.65).

CONCLUSION

Bupropion showed a significant modest reduction in ATS use and ATS craving (both rated as very low-quality evidence), larger in males (craving), and with longer treatment (ATS use). These results may inform future studies. More research is warranted on who might benefit from bupropion as ATSUD treatment.

Repeated chemogenetic activation of dopaminergic neurons induces reversible changes in baseline and amphetamine-induced behaviors

RATIONALE

Repeated chemogenetic stimulation is often employed to study circuit function and behavior. Chronic or repeated agonist administration can result in homeostatic changes, but this has not been extensively studied with designer receptors exclusively activated by designer drugs (DREADDs).

OBJECTIVES

We sought to evaluate the impact of repeated DREADD activation of dopaminergic (DA) neurons on basal behavior, amphetamine response, and spike firing. We hypothesized that repeated DREADD activation would mimic compensatory effects that we observed with genetic manipulations of DA neurons.

METHODS

Excitatory hM3D(Gq) DREADDs were virally expressed in adult TH-Cre and WT mice. In a longitudinal design, clozapine N-oxide (CNO, 1.0 mg/kg) was administered repeatedly. We evaluated basal and CNO- or amphetamine (AMPH)-induced locomotion and stereotypy. DA neuronal activity was assessed using in vivo single-unit recordings.

RESULTS

Acute CNO administration increased locomotion, but basal locomotion decreased after repeated CNO exposure in TH-CrehM3Dq mice relative to littermate controls. Further, after repeated CNO administration, AMPH-induced hyperlocomotion and stereotypy were diminished in TH-CrehM3Dq mice relative to controls. Repeated CNO administration reduced DA neuronal firing in TH-CrehM3Dq mice relative to controls. A two-month CNO washout period rescued the decreases in basal locomotion and AMPH response.

CONCLUSIONS

We found that repeated DREADD activation of DA neurons evokes homeostatic changes that should be factored into the interpretation of chronic DREADD applications and their impact on circuit function and behavior. These effects are likely to also be seen in other neuronal systems and underscore the importance of studying neuroadaptive changes with chronic or repeated DREADD activation.

Cocaine and amphetamine regulated transcript (CART): a newly characterized neuropeptide in human prostate

Cocaine and amphetamine regulated transcript (CART) is a somatostatin-like polypeptide. CART has been localized in the CNS, hypothalamo-pituitary-adrenocortical (HPA) axis, pancreatic islets and enteric nervous system. We investigated the cellular localization of CART in normal human prostate, benign prostatic hyperplasia, prostatic intraepithelial neoplasia and acinar adenocarcinoma. CART was assessed using immunohistochemistry (IHC) and in situ hybridization (ISH), and its gene expression was identified by RTqPCR. We found cellular expression of CART in both normal prostatic luminal secretory epithelial cells neuroendocrine cells (NEC) of both ducts and acini. The cellular appearance indicated a cycle of neuropeptide synthesis and secretion as validated by ISH/IHC concordance. RTqPCR analysis also validated the immunohistochemical data and gene expression, which both indicated low to moderate expression in prostatic tissues. CART expression also was increased in both neuroendocrine and glandular epithelial cell populations from samples of benign prostatic hyperplasia as validated by IHC, ISH and RTqPCR. CART expression was markedly diminished and, in some cases, entirely absent in tissues of prostatic intraepithelial neoplasia and adenocarcinoma. Owing to loss of CART expression in adenocarcinoma and its increase in benign prostatic hyperplasia, CART may prove to be an important prostate marker.

Atypical HUS with multiple complement system mutations triggered by synthetic psychoactive drug abuse: a case report

Atypical hemolytic uremic syndrome is a rare disorder with an estimated annual incidence of about two cases per million in the adult population. It is caused by the overactivation of the alternative pathway of the complement system. The disease can be triggered by many factors, including pregnancy, viral diseases, and sepsis; approximately 30% of atypical hemolytic uremic syndrome cases are caused by unknown processes. We present a case of a patient with C3-complement system mutations and aHUS triggered by the use of a new synthetic psychoactive drug.

Short-active gestational photoperiod reduces effortful choice behavior in mice, partial normalization by d-amphetamine

RATIONALE

Seasonal birth patterns consistently implicate winter gestation as a risk factor for several psychiatric conditions. We recently demonstrated that short-active (SA; 19:5 light:dark)-i.e., "winter-like"-photoperiod exposure across gestation and early life (E0-P28) induces psychiatrically relevant behavioral abnormalities in adult mice, including reduced immobility in the forced swim test (FST) and effortful amotivation. It is unknown, however, whether these effects were driven primarily by prenatal or postnatal mechanisms, and whether perinatal SA photoperiod would similarly reduce effort expenditure in a task relevant to everyday decision-making.

OBJECTIVES AND METHODS

We first tested male and female mice exposed to either gestational (E0-P0) or postnatal (E0-P28) SA photoperiod in the FST to determine whether the previously observed alteration was driven primarily by prenatal versus postnatal photoperiod. We then assessed whether SA gestational photoperiod reduces effortful choice behavior in the cross-species effort-based decision-making task (EBDMT) and whether any such deficit could be remediated by d-amphetamine (0.1 and 0.3 mg/kg, i.p.).

RESULTS

Mice exposed to prenatal, but not postnatal, SA photoperiod exhibited reduced FST immobility relative to controls and also demonstrated condition-dependently reduced preference for high-effort/high-reward versus low-effort/low-reward contingencies in the EBDMT. This effortful choice deficit was normalized by 0.1 mg/kg amphetamine.

CONCLUSIONS

These data: (1) suggest a greater contribution of gestational versus postnatal light conditions to the behavioral effects of perinatal SA photoperiod; and (2) implicate altered dopamine signaling in the behavioral phenotype of the SA-born mouse and possibly in the etiology of winter gestation-associated cases of psychiatric disease.

The role of sex and drug use during adolescence in determining the risk for adverse consequences of amphetamines

Use of amphetamines during adolescence, a critical period of brain development and reorganization, may lead to particularly adverse outcomes that are long-lasting. Similarly, female users may be uniquely vulnerable to certain aspects of drug use. A recognition of the role of use during adolescence and sex on outcomes of amphetamine and methamphetamine exposure are of critical importance in understanding and treating substance use disorders. This chapter highlights what human research, which has been largely epidemiological, suggests about sex and age differences in drug use patterns and outcomes. We also discuss work in laboratory animals that has typically utilized rats or mice exposed to drugs in a non-contingent manner (i.e., involuntarily) or through volitional self-administration. Lastly, we draw attention to the fact that advancing our understanding of the effects of amphetamine and methamphetamine use, the development of problematic drug taking, and the mechanisms that contribute to relapse will require an emphasis on inclusion of age and sex as moderating factors in future studies.

Wastewater profiling of illicit drugs, an estimation of community consumption: A case study of eThekwini Metropolitan Municipality, South Africa

Estimation of community-wide consumption of illicit drugs through wastewater analysis is a new concept in Africa although widely applied in developed nations as wastewater-based epidemiology (WBE). It is an important tool that can be used in understanding supply and demand patterns of illicit drug use on a local, national, and international scale. Information on illicit drug use is currently limited in Africa, because of a lack of monitoring structures by governments and financial constraints. This study hopes to bridge that gap by contributing to Africa's baseline information on illicit drug use. This study provides the first application of wastewater analysis to quantitatively evaluate daily illicit drug use in the eThekwini Metropolitan Municipality of KwaZulu-Natal Province of South Africa by quantifying the major urinary excreted metabolites, called drug target residues (DTRs), in raw wastewater from four major wastewater treatment plants (WWTPs) sampled for a week. The results showed that cocaine was the dominant illicit drug consumed in the catchment followed by amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine and 3,4-methylenedioxyamphetamine, with a per capita use of 360-3000 mg day-1 1000 inh-1, 47-800 mg day-1 1000 inh-1, 19-120 mg day -1 1000 inh-1, not detected (ND) to 4.9 mg day-1 1000 inh-1, and ND to 410 g day-1 1000 inh-1 respectively. The weekly usage patterns between the four WWTPs differed probably due to the lifestyle of the populace serving the different WWTPs. These results provide useful data on illicit drug use in eThekwini that can be utilised by public health agencies to implement suitable response strategies.

Antagonism of D2 receptors via raclopride ameliorates amphetamine-induced associative learning deficits in male mice

Dopamine levels in the dorsomedial striatum (DMS) are highly dynamic and are thought to underly the encoding of action-outcome associations. Although it is known that amphetamine disrupts the learning that is required for goal-directed action, the role of D1 and D2 receptors in this process has not been established. In this study, we examined the role of D1 and D2 receptor antagonists on learning in response to amphetamine. We used the outcome-specific devaluation task to examine goal-directed action in male C57BL6/J mice treated systemically with either a D1 antagonist (SCH-23990; 0.01 mg/kg) or a D2 antagonist (raclopride; 0.5 mg/kg) and then administered amphetamine (1 mg/kg). The mice were injected repeatedly throughout the instrumental training phase of the task to assess the impact on the learning of action-outcomes, and the subsequent choice test assessing performance of goal-directed action was conducted drug free. Effects of chronic drug administration on locomotor behaviour was assessed before and after the choice test. Treatment during learning with either amphetamine, or the D1 or D2 antagonists, impaired the subsequent performance of goal-directed action. The amphetamine-induced impairment in goal-directed action was reversed in mice treated with raclopride, but not when treated with SCH-23990. By contrast, amphetamine-induced hyperactivity was reversed in mice treated with SCH-23990, but not in mice treated with raclopride. Taken together, these data support the role of a balance of dopamine receptor signalling after amphetamine treatment. While overall D1 receptor availability is necessary to promote learning, in a state of elevated dopamine, modifying D2 receptor function can ameliorate learning deficits.

The Effectiveness of Topiramate in the Treatment of Amphetamine and Methamphetamine Use Disorder: A Randomized Controlled Trial

Objective: Limited studies have yet evaluated the effectiveness of topiramate in the treatment of amphetamine and methamphetamine addiction. Therefore, the aim of this study was to investigate the effectiveness of topiramate in the treatment of patients with this disorder. Methods: In this randomized, double-blind, placebo-controlled clinical trial, 52 patients with amphetamine and methamphetamine use disorder, within the age range of 16-60 years, were randomly divided into an intervention group (n = 26) and a placebo group (n = 26). The intervention group was treated with topiramate tablets with a starting dose of 50 mg, which was gradually increased to the target dose of 200 mg. The control group was treated with placebo. The duration of drug intervention in this clinical trial was 12 weeks, and all participants were evaluated before the intervention and 2, 4, 6, 8, 10, and 12 weeks after beginning the intervention. The Beck Depression Inventory, drug use temptation questionnaire, urine test, and side effects questionnaire were used as outcome measures to assess the patients. The data were analyzed using chi-square, independent t-test, and analysis of variance with repeated measurements. Results: There was no significant difference between the intervention and placebo groups in depression at the beginning of the treatment and at the 4th, 8th, and 12th weeks after the intervention (P > 0.05). The urine test also showed no significant difference between the two groups at any of the evaluation stages (P > 0.05). Although there was no significant difference between the two groups in the drug use temptation results at the beginning and the 2nd, 4th and 6th weeks (P > 0.05), the level of drug temptation in the intervention group was significantly lower than the placebo group in the 8th, 10th, and 12th weeks (P < 0.05). Conclusion: Topiramate can be effective in reducing the desire to use amphetamine and methamphetamine. However, further studies are needed to confirm these results.

Dopamine transporter membrane mobility is bidirectionally regulated by phosphorylation and palmitoylation

The primary regulator of dopamine availability in the brain is the dopamine transporter (DAT), a plasma membrane protein that drives reuptake of released dopamine from the extracellular space into the presynaptic neuron. DAT activity is regulated by post-translational modifications that establish clearance capacity through impacts on transport kinetics, and dysregulation of these events may underlie dopaminergic imbalances in mood and psychiatric disorders. Here, using fluorescence recovery after photobleaching, we show that phosphorylation and palmitoylation induce opposing effects on DAT lateral membrane mobility, which may influence functional outcomes by regulating subcellular localization and binding partner interactions. Membrane mobility was also impacted by amphetamine and in polymorphic variant A559V in directions consistent with enhanced phosphorylation. These findings grow the list of DAT properties controlled by these post-translational modifications and highlight their role in establishment of dopaminergic tone in physiological and pathophysiological states.

Early onset Parkinson's disease in the cycle of 3,4-methylenedioxymethamphetamine and substance use: a case report

BACKGROUND

Current evidence linking the development of Parkinson's disease after the use of 3,4-methylenedioxymethamphetamine is mixed and limited, with only a few positive case reports demonstrating this.

CASE PRESENTATION

We examine this interesting case of a 49-year-old Chinese gentleman who used 3,4-methylenedioxymethamphetamine and subsequently developed early onset Parkinson's disease at age 38 years. He had a family history of Parkinson's disease, though the onset of his symptoms was significantly earlier than those of his family members. MDMA was a likely precipitating factor for the early onset of his symptoms. He then conversely used methamphetamines to augment his treatment of Parkinson's symptoms. In the treatment of his Parkinson's disease, dopamine replacement therapy and deep brain stimulation could perpetuate addictive behaviors such as dopamine dysregulation syndrome, and similarly perpetuate substance use in vulnerable individuals. He had also been diagnosed with a human immunodeficiency virus infection at age 43, and his antiretroviral therapy contributed to depressive symptoms, which then complicated the management of his substance use. We examined the importance of managing his subsequent psychiatric and medical comorbidities to prevent their debilitating psychosocial impacts.

CONCLUSIONS

This case implies that 3,4-methylenedioxymethamphetamine use may precipitate the early development of Parkinson's disease in patients with genetic vulnerability. This highlights the risk in patients potentially paradoxically using substances to alleviate symptoms of Parkinson's, which can in turn perpetuate the disease process.

Knock-out of the critical nitric oxide synthase regulator DDAH1 in mice impacts amphetamine sensitivity and dopamine metabolism

The enzyme dimethylarginine dimethylaminohydrolase 1 (DDAH1) plays a pivotal role in the regulation of nitric oxide levels by degrading the main endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA). Growing evidence highlight the potential implication of DDAH/ADMA axis in the etiopathogenesis of several neuropsychiatric and neurological disorders, yet the underlying molecular mechanisms remain elusive. In this study, we sought to investigate the role of DDAH1 in behavioral endophenotypes with neuropsychiatric relevance. To achieve this, a global DDAH1 knock-out (DDAH1-ko) mouse strain was employed. Behavioral testing and brain region-specific neurotransmitter profiling have been conducted to assess the effect of both genotype and sex. DDAH1-ko mice exhibited increased exploratory behavior toward novel objects, altered amphetamine response kinetics and decreased dopamine metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) level in the piriform cortex and striatum. Females of both genotypes showed the most robust amphetamine response. These results support the potential implication of the DDAH/ADMA pathway in central nervous system processes shaping the behavioral outcome. Yet, further experiments are required to complement the picture and define the specific brain-regions and mechanisms involved.

Methamphetamine alters nucleus accumbens neural activation to monetary loss in healthy young adults

RATIONALE

Stimulant drugs like methamphetamine (MA) activate brain reward circuitry, which is linked to the development of problematic drug use. It is not clear how drugs like MA alter neural response to a non-drug reward.

OBJECTIVES

We examined how acute MA impacts neural response to receipt of a monetary reward relative to a loss in healthy adults. We hypothesized that MA (vs. placebo) would increase mesolimbic neural activation to reward, relative to loss.

METHODS

In a within-subject, randomized, cross-over, double-blind, placebo-controlled design, 41 healthy adults completed the Doors monetary reward task during fMRI after ingestion of placebo or 20 mg MA. We examined drug effects on neural response to reward receipt (Win vs. Loss) using a priori anatomical striatal regions of interest (nucleus accumbens (NAcc), caudate, putamen).

RESULTS

MA decreased NAcc BOLD activation to reward vs loss compared to placebo (p=.007) without altering caudate or putamen BOLD activation. Similar effects for reward vs. loss were obtained using whole brain analysis. Additional exploratory ROI analysis comparing reward and loss activation relative to a neutral "fixation" period indicated that MA increased NAcc BOLD activation during loss trials, without decreasing activation during win trials.

CONCLUSIONS

This preliminary evidence suggests that MA increases NAcc neural response to the receipt of monetary loss. Additional studies are needed to replicate our findings and clarify the mechanisms contributing to altered mesolimbic neural response to reward and loss receipt during stimulant intoxication.

Pre-injury stimulant use in isolated severe traumatic brain injury: effect on outcomes

PURPOSE

The aim of this study was to assess the impact of pre-injury stimulant use (amphetamine, cocaine, methamphetamine and/or ecstasy) on outcomes after isolated severe traumatic brain injury (TBI).

METHODS

Retrospective 2017 TQIP study, including adult trauma patients (≥16 years old) who underwent drug and alcohol screening on admission and sustained an isolated severe TBI (head AIS ≥3). Patients with significant extracranial trauma (AIS ≥3) were excluded. Epidemiological and clinical characteristics, procedures and outcome variables were collected. Patients with isolated stimulant use were matched 1:1 for age, gender, mechanism of injury, head AIS and overall comorbidities, with patients with negative toxicology and alcohol screen. Outcomes in the two groups were compared with univariable and multivariable regression analysis.

RESULTS

681 patients with isolated TBI and stimulant use were matched with 681 patients with negative toxicology and alcohol screen. The incidence of hypotension and CGS <9 was similar in the two groups. In multivariable regression analysis, stimulant use was not independently associated with mortality (OR 0.95, 95% CI 0.61-1.49). However, stimulant use was associated with longer hospital length of stay (HLOS) (RC 1.13, 95%CI 1.03-1.24).

CONCLUSION

Pre-injury stimulant use is common in patients admitted for severe TBI, but was not independently associated with mortality when compared to patients with negative toxicology. However, stimulant use was associated with a significant longer HLOS.

Prevalence and correlates of substance use among school-going adolescents (11-18years) in eight Sub-Saharan Africa countries

BACKGROUND

Substance use constitutes a major public health issue especially among adolescents as it has associated adverse behavioural, health, social and economic outcomes. However, there is a paucity of comprehensive evidence on the prevalence and associated factors of substance use (alcohol, marijuana and amphetamine) among school-going adolescents in sub-Saharan Africa (SSA). This study examined the magnitude of substance use and its associated factors among school-going adolescents in eight eligible sub-Saharan Africa countries.

METHODS

Data for the study were obtained from the Global School-based Health Survey (2012-2017) of 8 countries in SSA (N = 16,318).

RESULTS

Findings showed overall prevalence rates of 11.3% (95%CI = 10.8 - 11.8%), 2% (95%CI = 1.8 - 2.2%) and 2.6% (95%CI = 2.3 - 2.9%) for current alcohol use, current marijuana use and lifetime amphetamine use, respectively between 2012 and 2017. Late adolescence (15-18 years), being male, anxiety, bullying, fighting, truancy, having close friends, current cigarette smoking and tobacco use are significant risk factors for alcohol use. Anxiety, truancy, current cigarette smoking, tobacco use and suicidal attempt are significant risk factors for marijuana use. Anxiety, bullying, truancy, current cigarette smoking, tobacco use and suicidal attempt are significant risk factors for amphetamine use. Parental knowledge of activity, supervision and respect of privacy are significant protective factors of substance use.

CONCLUSION

There is the need for comprehensive public health policies beyond school-based psycho-behavioural interventions targeting the significant risk factors of substance use among school-going adolescents in SSA.

Association between ADHD symptoms and illicit stimulants use following 1 year among French university students of the i-Share cohort

PURPOSE

Although attention deficit hyperactivity disorder (ADHD) has been associated with illicit stimulants use, less is known about their prospective association in university students. We aimed to examine the association between ADHD symptoms at inclusion and illicit stimulants use following 1 year among university students.

METHODS

The i-Share cohort recruited French students from February 2013 to July 2020. The study included 4270 participants. The Adult ADHD Self-Report Scale (ASRS) was used to evaluate ADHD symptoms at inclusion. Illicit stimulants use was assessed at inclusion and 1 year after inclusion. Multivariable logistic regressions were conducted to assess the association between ADHD symptoms at inclusion and illicit stimulants use following 1 year.

RESULTS

High levels of ADHD symptoms at inclusion were associated with a greater probability of illicit stimulants use following 1 year (adjusted OR: 2.42 (1.51-3.8)). The adjusted odds ratio was 2.7 (1.08-7.84) among participants who had used illicit stimulant at least once (continuation) and 2.25 (1.04-4.37) among participants who had never used illicit stimulants at inclusion (initiation).

CONCLUSION

High levels of ADHD symptoms are a feature that may promote both initiation and continuation of illicit stimulants use among university students. Our findings suggest that university students with high levels of ADHD symptoms may benefit from screening to help identify those at risk of illicit stimulants use.

Vanillic acid alleviates methamphetamine-induced mitochondrial toxicity in cardiac mitochondria via antioxidant activity and inhibition of MPT Pore opening: an in-vitro study

BACKGROUND

Methamphetamine is widely abused in all parts of the world. It has been reported that short-term and long-term methamphetamine exposure could damage the dopaminergic system and induce cardiomyopathy and cardiotoxicity via mitochondrial dysfunction and oxidative stress. Vanillic acid (VA), a phenolic acid compound derived from plants, is known for its antioxidant and mitochondrial protection properties.

METHODS

In the current study we used VA for attenuating of Methamphetamine-induced mitochondrial toxicity in cardiac mitochondria. Isolated mitochondria obtained from rat heart were grouped as: control, methamphetamine (250 µM), VA (10, 50 and 100 µM) was cotreated with methamphetamine (250 µM) and VA (100 µM) alone. After 60 min, mitochondrial fraction including: succinate dehydrogenases (SDH) activity, mitochondrial membrane potential (MMP), mitochondrial swelling, mitochondrial glutathione (GSH), reactive oxygen species (ROS) and lipid peroxidation (LPO) were evaluated.

RESULTS

Methamphetamine exposure significantly disrupted mitochondrial function and induced ROS formation, lipid peroxidation, GSH depletion, MMP collapse and mitochondrial swelling, while VA significantly increased SDH activity as indicator of mitochondrial toxicity and dysfunction. VA also significantly decreased ROS formation, lipid peroxidation, mitochondrial swelling, MMP collapse and depletion of GSH in cardiac mitochondria in the presence of methamphetamine.

CONCLUSION

These findings suggested that VA is able to reduce methamphetamine-induced mitochondrial dysfunction and oxidative stress. Our results demonstrate that VA could potentially serve as a promising and accessible cardioprotective agent against methamphetamine-induced cardiotoxicity, via antioxidant and mitochondrial protection properties.

Caloric state modulates locomotion, heart rate and motor neuron responses to acute administration of d-amphetamine in zebrafish larvae

Psychostimulant drugs increase behavioral, cardiac and brain responses in humans and other animals. Acute food deprivation or chronic food restriction potentiates the stimulatory effects of abused drugs and increases the propensity for relapse to drug seeking in drug-experienced animals. The mechanisms by which hunger affects cardiac and behavioral activities are only beginning to be elucidated. Moreover, changes in motor neuron activities at the single neuron level induced by psychostimulants, and their modulation by food restriction, remain unknown. Here we investigated how food deprivation affects responses to d-amphetamine by measuring locomotor activity, cardiac output, and individual motor neuron activity in zebrafish larvae. We used wild-type larval zebrafish to record behavioral and cardiac responses and the larvae of Tg(mnx1:GCaMP5) transgenic zebrafish to record motor neuron responses. Physiological state gated responses to d-amphetamine. That is, d-amphetamine evoked significant increases in motor behavior (swimming distances), heart rate and motor neuron firing frequency in food-deprived but not fed zebrafish larvae. The results extend the finding that signals arising from food deprivation are a key potentiator of the drug responses induced by d-amphetamine to the zebrafish model. The larval zebrafish is an ideal model to further elucidate this interaction and identify key neuronal substrates that may increase vulnerability to drug reinforcement, drug-seeking and relapse.

Identifying early intervention opportunities for illicit stimulant use: A cross-sectional study of factors associated with illicit stimulant use among young people accessing integrated youth services in British Columbia, Canada

INTRODUCTION

Illicit stimulant (cocaine and/or amphetamine) use among young people aged 12-24 is a public health priority given that substance use initiation tends to peak in this developmental period and significant associated immediate and long-term harms are associated with its use. Young people using stimulants must be engaged in services as early as possible to reduce these harms. To inform early intervention opportunities, this study aimed to identify the risk/protective factors associated with illicit stimulant use among young people.

METHODS

We conducted a cross-sectional study on routinely collected self-reported data among young people accessing integrated youth services in British Columbia (Canada) between April 2018 and January 2022. Data were collected on young peoples' socio-demographic characteristics, and social, behavioral, and health profiles. Variable selection was guided by established risk/protective factors for substance use among young people. The study used multivariable logistic regression to identify risk/protective factors that were independently associated with past 30-day illicit stimulant use.

RESULTS

The analytic sample included n = 5620 young people aged 12-24 and a total of 163 (2.9 %) reported past 30-day illicit cocaine and/or amphetamine use. Demographic characteristics that were independently associated with illicit stimulant use included older age (aOR = 1.27, 95 % CI = 1.17-1.38) and gender identity as man vs woman (aOR = 1.71, 95 % CI = 1.10-2.70). Social and environmental risk factors included recently witnessing or experiencing violence (aOR = 2.32, 95 % CI = 1.47-3.68) and higher past-year crime/violent behaviors score (aOR = 1.39, 95 % CI = 1.13-1.69). Finally, regular alcohol (aOR = 6.90, 95 % CI = 2.36-25.42), regular (aOR = 3.74, 95 % CI = 1.95-7.54) or social (aOR = 3.06, 95 % CI = 1.44-6.60) tobacco use, and lifetime hallucinogen (aOR = 3.24, 95 % CI = 1.8-5.91) and ecstasy/MDMA (aOR = 2.53, 95 % CI = 1.48-4.39) use were also statistically significant risk factors.

CONCLUSIONS

These risk/protective factors support identification of young people who may benefit from further screening, assessment, and treatment for illicit stimulant use. This study also underscores the need to expand early intervention and harm reduction programs that can comprehensively respond to young peoples' stimulant use, health, and social needs.

Adsorption of amphetamine on deep eutectic solvents functionalized graphene oxide/metal-organic framework nanocomposite: Elucidation of hydrogen bonding and DFT studies

The efficient and selective removal of amphetamine (AMP) from water bodies is significant for environmental remediation. In this study, a novel strategy for screening deep eutectic solvent (DES) functional monomers was proposed based on density functional theory (DFT) calculations. Using magnetic GO/ZIF-67 (ZMG) as substrates, three DES-functionalized adsorbents (ZMG-BA, ZMG-FA, and ZMG-PA) were successfully synthesized. The isothermal results showed that the DES-functionalized materials introduced more adsorption sites and mainly contributed to the formation of hydrogen bonds. The order of the maximum adsorption capacity (Q_m) was as follows: ZMG-BA (732.110 μg⋅g^-1) > ZMG-FA (636.518 μg⋅g^-1) > ZMG-PA (564.618 μg⋅g^-1) > ZMG (489.913 μg⋅g^-1). The adsorption rate of AMP on ZMG-BA was the highest (98.1%) at pH 11, which could be explained by the less protonation of -NH₂ from AMP being more favorable for forming hydrogen bonds with the -COOH of ZMG-BA. The strongest affinity of the -COOH of ZMG-BA for AMP was reflected in the most hydrogen bonds and the shortest bond length. The hydrogen bonding adsorption mechanism was fully explained by experimental characterization (FT-IR, XPS) and DFT calculations. Frontier Molecular Orbital (FMO) calculations showed that ZMG-BA had the lowest HOMO-LUMO energy gap (E_gap), the highest chemical activity and the best adsorption capability. The experimental results agreed with the results of theoretical calculations, proving the validity of the functional monomer screening method. This research offered fresh suggestions for the functionalized modification of carbon nanomaterials to achieve effective and selective adsorption for psychoactive substances.

Clinical management of psychostimulant withdrawal: review of the evidence

It is estimated that a majority of people who use psychostimulants, particularly methamphetamine (MA) and cocaine, experience withdrawal upon abstinence from sustained use. This review of clinical research reports the evidence regarding biomedical and behavioral treatments for psychostimulant withdrawal symptoms. It provides a framework for clinicians and scientists to increase impact on attenuating MA and cocaine withdrawal during initial and sustained abstinence. Articles reviewed included reports of controlled clinical trials (randomized or non-randomized) reporting at least one withdrawal symptom among the outcomes or specifically studying patients in withdrawal. Potential efficacy for MA withdrawal is noted for a few medications (mirtazapine, naltrexone, bupropion) and repetitive transcranial magnetic stimulation during acute (first week), early protracted (weeks 2-4) and late protracted (> 4 weeks) withdrawal phases. Topiramate shows mixed evidence of efficacy for cocaine withdrawal. In general, there is inconsistent signal for biomedical and behavioral treatments on MA and cocaine withdrawal.

Trends in amphetamine prescriptions given at discharge in emergency departments: A national analysis (2012-2019)

OBJECTIVES

In parallel with the opioid epidemic, there has been a resurgence in abuse, medical complications, and deaths related to amphetamines. The opioid epidemic began with increasing rates of prescription products that evolved overtime to include heroin and more recently, fentanyl analogues. Current trends in amphetamine prescriptions are less well described. We sought to determine if there has been a change in amphetamine prescriptions given at discharge in U.S. emergency departments (EDs) in recent years.

METHODS

We conducted a retrospective review of data provided by the National Hospital Ambulatory Medical Care Survey (NHAMCS) from 2012 to 2019. We computed total number of visits that were given amphetamine prescriptions (amphetamine salts, methylphenidate derivatives, and dexmethylphenidate) at discharge for each year. We computed the total number and rate of visits (of all ED visits) that had both amphetamines and opioids prescribed at discharge over the years. We computed data normality using Shapiro Wilke's test and used descriptive statistics such as mean to describe the data distribution as applicable. We used spearman's rho (SR) or pearson's correlation (PC) as applicable to describe trends in data. All p-values were one-tailed and were reported at a 0.05 significance level. All analyses were conducted in IBM SPSS version 28.

RESULTS/FINDINGS

From 2012 to 2019, there were an estimated 817,895 ED visits where an amphetamine prescription was given at discharge, with an overall strong increase in rate over time (SR = 0.71, p = 0.02). At the beginning of the study period (2012) there were 83,503 (0.06%) visits and in 2019 there were 186,539 (0.12%) visits (123% absolute increase). On average, there were 102,237 (SD: 52,725) visits with discharge amphetamine prescriptions per year. There was a strong, linear increase in number of visits that involved a discharge amphetamine salt prescription (PC = 0.92, p = 0.001). In 2012, there were a total of 23,676 visits and in 2019, a total of 124,773 visits (427% increase). There was no trend in visits where both an amphetamine and opioid were prescribed (PC: 0.61, p = 0.06).

CONCLUSION

There have been increases in discharge prescriptions for amphetamines in the ED over time. This was largely driven by prescriptions for amphetamine salts. Future research initiatives should continue to monitor this trend and in prescriptions and associated abuse in the setting of rising amphetamine abuse.

Endocannabinoid system as a therapeutic target for psychostimulants relapse: A systematic review of preclinical studies

The mechanism behind the reinstament of psychostimulant, as a major obstacle in addiction treatment is not fully understood. Controversial data are available in the literature concerning the role of the endocannabinoid (eCB) system in regulating the relapse to psychostimulant addiction in preclinical studies. The current systematic review aims to evaluate eCB modulators' effect in the reinstatement of commonly abused psychostimulants, including cocaine, amphetamine, methamphetamine, and 3,4-methylenedioxymethamphetamine. By searching the PubMed, Web of Science, and Scopus databases, studies were selected. Then the studies^, quality was evaluated by the SYRCLE risk of bias tool. The results have still been limited to preclinical studies. Thirty-nine articles that employed self-administration and CPP as the most prevalent animal models of addiction were selected. This data indicates that cannabinoid receptor 1 antagonists and some cannabinoid receptor 2 agonists could suppress the reinstatement of cocaine and methamphetamine addiction in a dose-dependent manner. However, only AM251 was efficient to block the reinstatement of 3,4-methylenedioxymethamphetamine. In conclusion, cannabinoid receptor 1 antagonists and some cannabinoid receptor 2 agonists may have curative potential in the relapse of psychostimulant abuse. However, time, dose, and route of administration are crucial factors in their inhibitory impacts.

Priming effects of a slot machine game and amphetamine on probabilistic risk-taking in people with gambling disorder and healthy controls

INTRODUCTION

The Game of Dice Task (GDT) captures probabilistic risk-taking, which is an important feature of addictions and integral to gambling disorder (GD). No research appears to have assessed effects of gambling-specific priming manipulations or the pharmacological basis of such effects on the GDT.

AIMS

To investigate effects of slot machine gambling (Slots) and d-amphetamine (AMPH; 20 mg) on risk-taking in people with GD and healthy controls (HCs) (n = 30/group). The role of dopamine (DA) was assessed by pre-treating participants with the D2 receptor (D2R)-preferring antagonist, haloperidol (HAL; 3-mg) or mixed D1R-D2R antagonist, fluphenazine (FLU; 3-mg).

HYPOTHESES

Slots and AMPH will each increase risk-taking based on fewer (less probable) possible outcomes selected (POS) and poorer net monetary outcomes (NMO; gains minus losses) on the GDT, with stronger effects in Group GD. If DA mediates these effects, outcomes will vary with pre-treatment.

METHOD

Participants attended a pre-experimental baseline session and 4 test sessions. Antagonist Group (HAL, FLU) was manipulated between-participants. Pre-treatment (antagonist, placebo) was manipulated within-participants and counterbalanced over sessions for Slots and AMPH test phases. Moderator/mediator effects of trait and neuropsychological factors and GD severity (South Oaks Gambling Screen; SOGS) were explored via covariance.

RESULTS

AMPH led to an escalation in risky POS over trial blocks in both groups, regardless of pre-treatment. Cognitive inflexibility (high perseveration-proneness) moderated this effect in Group HC. In Group GD, SOGS selectively predicted riskier POS on AMPH sessions. Group GD achieved poorer NMO vs. Group HC on the pre-experimental baseline and Placebo-Slots sessions. Group HC selectively displayed poorer NMO on the Antagonist-Slots session.

CONCLUSIONS

The GDT can detect behavioral and pharmacological priming effects. Cognitive inflexibility and symptom severity moderate AMPH-induced risk-taking in HC and GD participants, respectively. Sensitization-related "wanting" of risk may contribute to the latter effect in people with GD.

Electronic band structure and density of state modulation of amphetamine and ABW type-zeolite adsorption system: DFT-CASTEP analysis

The structured abstract is combined from two parts: CONTEXT: The adsorption behavior of amphetamine (AMP) on the surface of ABW-aluminum silicate zeolite was implemented with a computational depiction. Studies of the electronic band structure (EBS) and density of states (DOS) were conducted to demonstrate transition behavior attributed to aggregate-adsorption interaction. Thermodynamic illustration of the studied adsorbate was studied to investigate the structural behavior of the adsorbate on the surface of the zeolite adsorbent. The best investigated models were assessed with adsorption annealing calculations related to adsorption energy surface. The periodic adsorption-annealing calculation model predicted a highly stable energetic adsorption system based on total energy, adsorption energy, rigid adsorption energy, deformation energy, and dE_ad/d_Ni ratio. METHODS: Cambridge sequential total energy package (CASTEP) based on density functional theory (DFT), under Perdew-Burke-Ernzerhof (PBE) basis set, was used to depict the energetic levels of the adsorption mechanism between AMP and ABW-aluminum silicate zeolite surface. DFT-D dispersion correction function was postulated for weakly interacted systems. Structural and electronic elucidations were described with geometrical optimization, FMOs, and MEP analyses. Thermodynamic parameters such as entropy, enthalpy, Gibbs free energy, and heat capacity over temperature dependence studied the conductivity behavior over localized energetic states based on Fermi level and described the disorder degree of the system.

Nystagmus among suspected amphetamine impaired drivers

Clinical signs of drug use can be helpful to identify which drug has been consumed. Amphetamine intake has traditionally not been considered to cause nystagmus. The aim of this study was to explore whether there is a relationship between amphetamine use and nystagmus in a population of apprehended drivers in a naturalistic setting. We evaluated drivers suspected of drug-impaired driving where blood samples were collected and a clinical test of impairment (CTI) was performed. Evaluation of nystagmus is one of the CTI subtests. The samples were analysed for alcohol and psychoactive drugs. Cases with a nystagmus test were recorded and amphetamine-only cases were compared with alcohol-only cases and with cases where alcohol or drugs were not detected, respectively. Samples from 507 amphetamine-only cases were compared to 485 alcohol-only cases and 205 drug-negative cases. The median blood amphetamine concentration was 0.37 mg/L and the median alcohol concentration was 1.57 g/kg. The proportion of cases with nystagmus was similar in amphetamine-only cases (21%) and drug-negative controls (25%), p = 0.273, but higher in alcohol-only cases (53%), p < 0.001. No association was found between the blood amphetamine concentration and degree of nystagmus (Spearman's ρ = 0.008, p = 0.860), whereas an association between blood alcohol concentration and degree of nystagmus was demonstrated (ρ = 0.249, p < 0.001). In conclusion, our study did not find that apprehended drivers using amphetamine had more frequently nystagmus than a control group that tested negative for alcohol and drugs, even at high amphetamine concentrations in blood. Hence, nystagmus should not be considered a tool for identifying amphetamine-induced impairment in drivers.

Prevalence and risk factors associated with psychostimulant use among Black individuals: A meta-analysis and systematic review

BACKGROUND

Psychostimulants (e.g., cocaine, amphetamine) are among the most widely used drugs globally with detrimental short and long-term physical, psychological and social consequences. There is limited data on psychostimulant use for various racial and ethnic groups, including Black people, and the challenges they face living as minorities overcoming historical challenges including increased incarceration associated with drug possession.

METHODS

Peer-reviewed articles were identified in five databases (APA PsycInfo, CINAHL, Cochrane CENTRAL, Embase, MEDLINE). Eligible studies were published in French or English, provided empiral data on psychostimulant use in Black individuals living in a minority context. The PRISMA guideline was used for structuring the review. Random-effects meta-analyses were generated to estimate the pooled prevalence of lifetime and periodic psychostimulant use among Black individuals using STATA 16.

RESULTS

Sixty-three studies published from 1991 to 2022 with a sample size of 139,683 Black individuals were included in the current meta-analysis. Results indicate a pooled prevalence estimate of 11.4% for any form of psychostimulant use among Black individuals. The pooled prevalence estimates were 12.4% (95% CI, 8.4% - 16.4%) for cocaine, 8.3% (95% CI, 0% - 19.1%) for amphetamines, and 11.4% (95% CI, 4.6% - 18.1%) for other stimulants. Prediction intervals for all psychostimulant types were highly heterogenous ranging from 0% to as high as 51.2% for amphetamine suggesting prevalence of use in some studies of Black people could be found to be as low as zero. Subgroup analyses were conducted to examine differences between age groups, gender, reference period, and type of assessment.

CONCLUSIONS

High prevalence rates of psychostimulant use among Black people argues for greater access to evidence-based treatments. However, current psychosocial interventions are suboptimal, warranting further study. Consideration needs to be given to the challenges of the large range of prediction intervals, living in urban areas, racial discrimination experiences, race-based stress, and sociodemographic characteristics, including poverty, education level, age, gender.

Methylphenidate cross-sensitization with amphetamine is dose dependent but not age dependent

Psychostimulants such as methylphenidate (MPD) and amphetamine (AMP) are often prescribed to young children and adolescents to treat behavioral disorders, or used to improve their intellectual performance in our competitive society. This is concerning as the temporal effects of how MPD exposure at a young age influences the response to MPD and AMP administration later in adulthood remains unclear. The objective of this study was to test whether MPD has the characteristics of substances that elicit behavioral symptoms of dependence and whether those effects are influenced by the initial age of MPD exposure. Three control and nine experimental groups of male rats were used. They were exposed to repetitive (chronic) 0.6, 2.5, or 10.0 mg/kg MPD in adolescence only, adulthood only, or adolescence and adulthood respectively. Then all groups were subsequently re-challenged with a single AMP dose in adulthood to test whether cross-sensitization between MPD and AMP was expressed, potentially as a result of prior MPD consumption. Exposure to 2.5 mg/kg and 10.0 mg/kg MPD in adolescence and adulthood or in adulthood alone led to cross-sensitization with AMP while exposure to 0.6 mg/kg MPD in adolescence and adulthood or in adulthood alone did not lead to cross-sensitization with AMP. Thus, these results indicate that MPD cross-sensitization with AMP is dose dependent.

Amphetamines modulate fentanyl-depressed respiration in a bidirectional manner

BACKGROUND

The opioid epidemic remains one of the most pressing public health crises facing the United States. Fentanyl and related synthetic opioid agonists have largely driven the rising rates of associated overdose deaths, in part, because of their surreptitious use as substitutes for other opioids and as adulterants in psychostimulants. Deaths involving opioids typically result from lethal respiratory depression, and it is currently unknown how co-use of psychostimulants with opioids affects respiratory toxicity. Considering psychostimulant overdoses have increased over 3-fold since 2013, and half of those co-involved opioids, this is a cardinal question.

METHODS

Naloxone, d-amphetamine (AMPH), and (±)-methamphetamine (METH) were evaluated for their effects on basal and fentanyl-depressed respiration. Minute volume (MVb) was measured in awake, freely moving mice via whole-body plethysmography to quantify fentanyl-induced respiratory depression and its modulation by dose ranges of each test drug.

RESULTS

Naloxone immediately reversed respiratory depression induced by fentanyl only at the highest dose tested (10 mg/kg). Both AMPH and METH exhibited bidirectional effects on MVb under basal conditions, producing significant (p ≤ 0.05) depressions then elevations of respiration as dose increased. Under depressed conditions the bidirectional effects of AMPH and METH on respiration were exaggerated, exacerbating and then reversing fentanyl-induced depression as dose increased.

CONCLUSIONS

These results indicate that co-use of amphetamines with fentanyl may worsen respiratory depression, but conversely, monoaminergic components of the amphetamines may possibly be exploited to mitigate fentanyl overdose.

Assessing the nature of premature responses in the rodent continuous performance test variable intertrial interval schedule using atomoxetine and amphetamine

BACKGROUND

Rodent operant tests that include premature responses (PR) as a measure of impulsivity commonly use variable intertrial interval (vITI) schedules. The rodent continuous performance test (rCPT) is suitable for a vITI schedule.

NEW METHOD

We optimised the analysis for a rCPT vITI schedule with intertrial intervals (ITIs) of 3, 6, and 12 s. Examining the nature of first (FiT) and following touches (FoT) to the blank screen led to a separate quantification of these two behaviours into the first touches level (%FiT) and the following-to-first touches ratio (FoT/FiT).

RESULTS

FiTs occurred more frequently in the 12 s ITIs than at shorter ITIs. Within 12 s ITIs, %FiT was only moderately higher during the last half than the first half, suggesting that long ITIs have a minimal effect on impulsivity, but allow a longer time for its detection. %FiT and the FoT/FiT ratio were uncorrelated. %FiT was negatively correlated with response criterion (C) and uncorrelated with discriminability. Conversely, FoT/FiT ratio was negatively correlated with discriminability, without correlation to C. Atomoxetine decreased %FiT but did not affect FoT/FiT ratio. Amphetamine increased %FiT and decreased the FoT/FiT ratio.

COMPARISON WITH EXISTING METHOD(S)

The results suggest that %FiT is analogous to %PR in related tasks and is a more suitable measure of waiting impulsivity in the rCPT. FoT/FiT ratio is unrelated to %FiT.

CONCLUSIONS

Long ITIs increase the detectability of, but has minimal effect on, waiting impulsivity. %FiT is analogous to %PR in related tasks, while the FoT/FiT ratio is a separate behaviour requiring further characterization.

GPR55 activation prevents amphetamine-induced conditioned place preference and decrease the amphetamine-stimulated inflammatory response in the ventral hippocampus in male rats

Inflammatory response in the Central Nervous System (CNS) induced by psychostimulants seems to be a crucial factor in the development and maintenance of drug addiction. The ventral hippocampus (vHp) is part of the reward system involved in substance addiction and expresses abundant G protein-coupled receptor 55 (GPR55). This receptor modulates the inflammatory response in vitro and in vivo, but there is no information regarding its anti-inflammatory effects and its impact on psychostimulant consumption. The aim of the present study was to investigate whether vHp GPR55 activation prevents both the inflammatory response induced by amphetamine (AMPH) in the vHp and the AMPH-induced conditioned place preference (A-CPP). Wistar adult male rats with a bilateral cannula into the vHp or intact males were subjected to A-CPP (5 mg/kg). Upon the completion of A-CPP, the vHp was dissected to evaluate IL-1β and IL-6 expression through RT-PCR, Western blot and immunofluorescence. Our results reveal that AMPH induces both A-CPP and an increase of IL-1β and IL-6 in the vHp. The GPR55 agonist lysophosphatidylinositol (LPI, 10 μM) infused into the vHp prevented A-CPP and the AMPH-induced IL-1β increase. CID 16020046 (CID, 10 μM), a selective GPR55 antagonist, abolished LPI effects. To evaluate the effect of the inflammatory response, lipopolysaccharide (LPS, 5 μg/μl) was infused bilaterally into the vHp during A-CPP acquisition. LPS strengthened A-CPP and increased IL-1β/IL-6 mRNA and protein levels in the vHp. LPS also increased CD68, Iba1, GFAP and vimentin expression. All LPS-induced effects were blocked by LPI. Our results suggest that GPR55 activation in the vHp prevents A-CPP while decreasing the local neuro-inflammatory response. These findings indicate that vHp GPR55 is a crucial factor in preventing the rewarding effects of AMPH due to its capacity to interfere with proinflammatory responses in the vHp.

Auditory discrimination and frequency modulation learning in schizophrenia patients: amphetamine within-subject dose response and time course

BACKGROUND

Auditory frequency modulation learning ('auditory learning') is a key component of targeted cognitive training (TCT) for schizophrenia. TCT can be effective in enhancing neurocognition and function in schizophrenia, but such gains require significant time and effort and elude many patients.

METHODS

As a strategy to increase and/or accelerate TCT-induced clinical gains, we tested the dose- and time-course effects of the pro-attentional drug, amphetamine (AMPH; placebo, 2.5, 5 or 10 mg po; within-subject double-blind, order balanced) on auditory learning in schizophrenia patients [n = 32; M:F = 19:13; age 42.0 years (24-55)]. To understand predictors and/or mechanisms of AMPH-enhanced TCT, we also measured auditory fidelity (words-in-noise (WIN), quick speech-in-noise (QuickSIN)) and neurocognition (MATRICS comprehensive cognitive battery (MCCB)). Some measures were also acquired from age-matched healthy subjects (drug free; n = 10; M:F = 5:5).

RESULTS

Patients exhibited expected deficits in neurocognition. WIN and QuickSIN performance at low signal intensities was impaired in patients with low v. high MCCB attention/vigilance (A/V) scores; these deficits were corrected by AMPH, maximally at 2.5-5 mg (d's = 0.79-1.29). AMPH also enhanced auditory learning, with maximal effects at 5 mg (d = 0.93), and comparable effects 60 and 210 min post pill. 'Pro-learning' effects of AMPH and AMPH-induced gains in auditory fidelity were most evident in patients with low MCCB A/V scores.

CONCLUSIONS

These findings advance our understanding of the impact of pro-attentional interventions on auditory information processing and suggest dose- and time-course parameters for studies that assess the ability of AMPH to enhance the clinical benefits of TCT in schizophrenia patients.

Characteristics of Amphetamine Psychosis with Respect to the Length of Drug Exposure

BACKGROUND

Over the past decade, the number of individuals requiring medical care for amphetamine-related psychosis has increased.

OBJECTIVE

This study aims to examine the psychological characteristics of amphetamine psychosis in drug-addicted patients depending on the length of drug exposure and compared to patients diagnosed with paranoid schizophrenia.

METHODS

The study was carried out in psychiatric clinic No. 1 in Kyiv (Ukraine) in 2019, involving 107 patients. Of all the participants, 50 were included in Group 1 (methamphetamine psychosis) and 57 - in Group 2 (paranoid schizophrenia). All patients were treated with medication to relieve exacerbating symptoms. They underwent extensive testing to determine the impairment severity of cognitive function, attention, and task performance during remission.

RESULTS

In Group 1, the timing of onset for paranoid symptoms depends on the length of amphetamine exposure (Spearman correlation coefficient = 0.89). The efficacy and dynamics of drug treatment in Group 2 were similar to patients in Group 1. However, the effect of reduction in Group 2 was achieved only in 4 months. Delusions, emotional disturbances, hallucinations in patients of Group 1 occurred 2.3 times more frequently than in Group 2 (p ≤ 0.05). The patients of Group 1 are characterized by the presence of disorders related to the affective and behavioral components.

CONCLUSION

All reported exacerbations are related to amphetamine use. Patients in Group 1 learned a smaller number of words compared to those in Group 2. Besides, a large number of errors and difficulties with shifting focus were recorded.