Major physical and psychological harms of methamphetamine use

Withdrawal symptoms in abstinent methamphetamine-dependent subjects

AIMS

Withdrawal symptoms have been linked to a propensity for relapse to drug abuse. Inasmuch as this association applies to methamphetamine (MA) abuse, an understanding of the course of MA withdrawal symptoms may help to direct treatment for MA dependence. Previous studies of symptoms manifested during abstinence from MA have been limited in size and scope. We asked (i) whether debilitating psychological and/or physical symptoms appear during the first several weeks of MA abstinence, (ii) how craving for MA evolves and (iii) whether psychiatric symptoms (e.g. depression, psychosis) persist beyond a month of abstinence.

DESIGN

A study of MA-dependent participants, who initiated and maintained abstinence from the drug for up to 5 weeks, compared to a matched healthy comparison group.

SETTING

In-patient research hospital ward (MA-dependent subjects) and out-patient (comparison subjects).

PARTICIPANTS

Fifty-six MA-dependent and eighty-nine comparison subjects.

MEASUREMENTS

Rater-assessed MA withdrawal questionnaire and self-report assessment of craving (MA-dependent subjects) and self-report assessment of psychiatric symptoms (both groups).

FINDINGS

At study entry, MA-dependent subjects exhibited a wide range in severity of depressive symptoms, with the average score at a mild-moderate level of severity. Symptoms of psychosis were also prevalent. While depressive and psychotic symptoms largely resolved within a week of abstinence, craving did not decrease significantly from the time of initiating abstinence until the second week, and then continued at a reduced level to the fifth week.

CONCLUSIONS

Depressive and psychotic symptoms accompany acute withdrawal from methamphetamine but resolve within 1 week. Craving is also present and lasts at least 5 weeks.

Methamphetamine neurotoxicity increases brain expression and alters behavioral functions of CB₁ cannabinoid receptors

Cannabis is the most common secondary illicit substance in methamphetamine (METH) users, yet the outcomes of the concurrent consumption of both substances remain elusive. Capitalizing on recent findings on the implication of CB₁ cannabinoid receptors in the behavioral effects of METH, we hypothesized that METH-induced neurotoxicity may alter the brain expression of CB₁, thereby affecting its role in behavioral functions. To test this possibility, we subjected rats to a well-characterized model of METH neurotoxicity (4 mg/kg, subcutaneous × 4 injections, 2 h apart), and analyzed their CB₁ receptor brain expression three weeks later. METH exposure resulted in significant enhancements of CB₁ receptor expression across several brain regions, including prefrontal cortex, caudate-putamen, basolateral amygdala, CA1 hippocampal region and perirhinal cortex. In parallel, a different group of METH-exposed rats was used to explore the responsiveness to the potent cannabinoid agonist WIN 55,212-2 (WIN) (0.5-1 mg/kg, intraperitoneal), within several paradigms for the assessment of emotional and cognitive functions, such as open field, object exploration and recognition, and startle reflex. WIN induced anxiolytic-like effects in METH-exposed rats and anxiogenic-like effects in saline-treated controls. Furthermore, METH-exposed animals exhibited a significantly lower impact of WIN on the attenuation of exploratory behaviors and short-term (90 min) recognition memory. Conversely, METH neurotoxicity did not significantly affect WIN-induced reductions in locomotor activity, exploration time and acoustic startle. These results suggest that METH neurotoxicity may alter the vulnerability to select behavioral effects of cannabis, by inducing distinct regional variations in the expression of CB₁ receptors.

Armodafinil in the treatment of sleep/wake disorders

Excessive sleepiness (ES) is a major but underestimated public health concern associated with significant impairments in alertness/wakefulness and significant morbidity. The term ES has been used in the sleep medicine literature for years, but due to its nonspecific symptoms (ie tiredness or fatigue), it frequently goes unrecognized or is misdiagnosed in primary care. In some cases ES arises due to poor sleep habits or self-imposed sleep deprivation; however, ES is also a key component of a number of sleep/wake disorders and multiple medical and psychiatric disorders. Identification and treatment of ES is critical to improve the quality of life and well-being of patients and for the safety of the wider community. The inability of patients to recognize the nature, extent, and symptomatic profile of sleep/wake disorders requires vigilance on the part of healthcare professionals. Interventions to address ES and its associated impairments, treatment of the underlying sleep/wake disorder, and follow-up are a priority given the potential for serious consequences if left untreated. Wakefulness-promoting agents are available that treat ES associated with sleep/wake disorders. This review examines current approaches for managing this debilitating and potentially life-threatening condition, focusing on the place of armodafinil as a wakefulness-promoting agent.

Violence perpetrated by women who use methamphetamine

Methamphetamine (meth) is widely recognized as being associated with violence and aggression. This association is found among women and men, with rates of meth-related violence among women possibly being equal to or even exceeding rates among men. This study examined female-perpetrated violence from the phenomenological point of view of 30 women (aged 18-45 years; mean age of 28.5 years) in residential treatment for meth dependence. Of the 30 participants, 80% (n = 24) reported experiencing violence in their lifetimes: 67% (n = 20) had violence perpetrated against them, and 57% (n = 17) had perpetrated violence. Most participants described perpetrating violence when they were 'coming down' off of meth (i.e. withdrawing). Five women (29%) attributed their violent behaviors to meth and said they would not have been violent had they not been using meth. In contrast, 10 women (59%) described pre-existing 'anger issues' that were 'enhanced' by meth. This article describes the timing of meth-related violence, bi-directional violence, men's responses to female-perpetrated violence, aggression in the context of sexual activities, and violence perpetrated against non-partners. A biopsychosocial theoretical framework is useful to interpret the complex explanations that women provide for their perpetration of violence under the influence of chronic meth use.

The toxicology of homicide offenders and victims: A review

ISSUES

The toxicology of homicide offenders and victims, and homicide as a cause of death among psychoactive substance users.

APPROACH

Review of the toxicology of homicide, and homicide as a cause of death among psychoactive substance users.

KEY FINDINGS

A half or more of offenders are intoxicated by a psychoactive substance at the time of the homicide, with alcohol the most commonly reported substance. Levels of substances among victims are comparable with those seen among perpetrators. Among both offenders and victims, levels of substances far exceed population use. Among substance users, homicide specific mortality rates of substance users far exceed population rates. Reducing rates of alcohol and other drug consumption, at national and individual levels, can be expected to substantially reduce rates of, and risk for, homicide.

CONCLUSIONS AND IMPLICATIONS

Psychoactive substances are strongly associated with homicide. One of the major societal benefits that can be derived from active attempts to reduce alcohol and other drug use are reductions in homicide rates.

Methamphetamine preconditioning causes differential changes in striatal transcriptional responses to large doses of the drug

Methamphetamine (METH) is a toxic drug of abuse, which can cause significant decreases in the levels of monoamines in various brain regions. However, animals treated with progressively increasing doses of METH over several weeks are protected against the toxic effects of the drug. In the present study, we tested the possibility that this pattern of METH injections might be associated with transcriptional changes in the rat striatum, an area of the brain which is known to be very sensitive to METH toxicity and which is protected by METH preconditioning. We found that the presence and absence of preconditioning followed by injection of large doses of METH caused differential expression in different sets of striatal genes. Quantitative PCR confirmed METH-induced changes in some genes of interest. These include small heat shock 27 kD proteins 1 and 2 (HspB1 and HspB2), brain derived neurotrophic factor (BDNF), and heme oxygenase-1 (Hmox-1). Our observations are consistent with previous studies which have reported that ischemic or pharmacological preconditioning can cause reprogramming of gene expression after lethal ischemic insults. These studies add to the growing literature on the effects of preconditioning on the brain transcriptome.

Methamphetamine use, aggressive behavior and other mental health issues among high-school students in Cape Town, South Africa

OBJECTIVE

Methamphetamine use has become a growing problem in a number of countries over the past two decades, but has only recently emerged in South Africa. This study investigated the prevalence of methamphetamine use among high-school students in Cape Town and whether students reporting methamphetamine use were more likely to be at risk for mental health and aggressive behavior problems.

METHODS

A cross-sectional survey of 15 randomly selected high schools in Cape Town, of 1561 males and females grade 8-10 students (mean age 14.9), was conducted using the Problem Oriented Screening Instrument for Teenagers (POSIT) and the Beck Depression Inventory (BDI).

RESULTS

Findings indicated that 9% of the students had tried methamphetamine at least once. Ordinal logistic regression analyses showed that methamphetamine use in the past year was significantly associated with higher aggressive behavior scores (OR=1.81, 95% CI: 1.04-3.15, p<0.05), mental health risk scores (OR=2.04, 95% CI: 1.26-3.31, p<0.01) and depression scores (OR=2.65, 95% CI: 1.64-4.28, p<0.001).

CONCLUSIONS

Methamphetamine use has become a serious problem in Cape Town, particularly among adolescents. Screening adolescents in school settings for methamphetamine use and behavior problems may be useful in identifying youth at risk for substance misuse, providing an opportunity for early intervention. These findings have implications for other parts of the world where methamphetamine use may be occurring at younger ages and highlight the importance of looking at co-morbid issues related to methamphetamine use.

Health outcomes associated with methamphetamine use among young people: a systematic review

OBJECTIVES

Methamphetamine (MA) use among young people is of significant social, economic and public health concern to affected communities and policy makers. While responses have focused upon various perceived severe harms of MA use, effective public health interventions require a strong scientific evidence base.

METHODS

We conducted a systematic review to identify scientific studies investigating health outcomes associated with MA use among young people aged 10-24 years. The International Classification of Diseases (ICD-10) was used to categorize outcomes and determine the level of evidence for each series of harms.

RESULTS

We identified 47 eligible studies for review. Consistent associations were observed between MA use and several mental health outcomes, including depression, suicidal ideation and psychosis. Suicide and overdose appear to be significant sources of morbidity and mortality among young MA users. Evidence for a strong association between MA use and increased risk of human immunodeficiency virus (HIV) and other sexually transmitted infections is equivocal. Finally, we identified only weak evidence of an association between MA use and dental diseases among young people.

CONCLUSIONS

Available evidence indicates a consistent relationship between MA use and mental health outcomes (e.g. depression, psychosis) and an increased risk of mortality due to suicide and overdose. We found insufficient evidence of an association between MA use and other previously cited harms, including infectious diseases and dental outcomes. As such, future research of higher methodological quality is required to further investigate possible associations. Current interventions should focus attention upon MA-related health outcomes for which sound scientific evidence is available.

Prevention of HIV infection among injection drug users in resource-limited settings

Injection drug use contributes to considerable global morbidity and mortality associated with human immunodeficiency virus (HIV) infection and AIDS and other infections due to blood-borne pathogens through the direct sharing of needles, syringes, and other injection equipment. Of approximately 16 million injection drug users (IDUs) worldwide, an estimated 3 million are HIV infected. The prevalence of HIV infection among IDUs is high in many countries in Asia and eastern Europe and could exacerbate the HIV epidemic in sub-Saharan Africa. This review summarizes important components of a comprehensive program for prevention of HIV infection in IDUs, including unrestricted legal access to sterile syringes through needle exchange programs and enhanced pharmacy services, treatment for opioid dependence (ie, methadone and buprenorphine treatment), behavioral interventions, and identification and treatment of noninjection drug and alcohol use, which accounts for increased sexual transmission of HIV. Evidence supports the effectiveness of harm-reduction programs over punitive drug-control policies.

Comparative rates of violent crime among regular methamphetamine and opioid users: offending and victimization

AIMS

To determine the comparative levels of violent offending and victimization among regular methamphetamine and heroin users.

DESIGN

Cross-sectional Setting Sydney, Australia.

PARTICIPANTS

A total of 400 regular methamphetamine (METH) and heroin (HER) users (118 methamphetamine users: METH; 161 regular heroin users: HER; 121 regular users of both: BOTH).

FINDINGS

Eighty-two per cent reported a life-time history of committing violent crime, 41% in the past 12 months. There were no group differences in life-time violence, but the METH group were significantly more likely than the HER group to have committed violence in the past 12 months (odds ratio 1.94). Nearly all (95%) reported that they had been a victim of violent crime, 46% in the preceding 12 months, with no group differences. Those who had committed a violent crime in the past 12 months were 13.23 times more likely to have been a victim in that period. The majority believed it unlikely that they would be a victim of (78%), or commit (87%), a violent crime in the next 12 months.

CONCLUSIONS

Regular methamphetamine use appears to be associated with an increased risk of violent offending, but not victimization, compared with heroin use.

Elite athletes' perceptions of the effects of illicit drug use on athletic performance

OBJECTIVE

To investigate the perceived risks and benefits that elite athletes associate with illicit drugs and their beliefs concerning the effects of recreational drug use on athletic performance.

DESIGN

Self-administered survey.

PARTICIPANTS

Nine hundred seventy-four elite athletes (mean age, 23 years; range, 18-30 years) were recruited from 8 national sporting organizations in Australia and the Australian Institute of Sport.

INTERVENTIONS

Participants completed a self-administered survey that included questions exploring participants' perceptions regarding the effects of illicit drug use on physical performance.

SETTING

National sporting organization meetings or competitions.

MAIN OUTCOME MEASURES

The main outcome measure was risk perception on athletic performance associated with illicit drug use.

RESULTS

The majority of athletes believed that illicit drug use would impact negatively on athletic performance. The main perceived effects of illicit drugs on athletic performance were physical and mental functioning. A minority of athletes indicated that drug use would not impact on physical performance when taken during the off-season or in moderation.

CONCLUSIONS

The main risks perceived in association with illicit drug use were short-term consequences, such as physical and mental functioning, rather than long-term health consequences. The current findings may contribute to the development of harm reduction strategies that communicate drug-related consequences to elite athletes in an appropriate and effective manner.

Stimulant-induced trichotillomania

A prior report described the presentation of cocaine-induced trichotillomania, which resolved with the cessation of cocaine use. Here the authors describe the case of stimulant-induced trichotillomania that resolved with the discontinuation of stimulants and initiation of olanzapine. To the authors' knowledge this is the first reported adult case of stimulant-induced trichotillomania. The case is of a patient with a previous diagnosis of attention deficit hyperactivity disorder whose symptoms of trichotillomania coincide with abuse of amphetamine and with the resolution of symptoms in the absence of amphetamine use. Given the increase in exposure of prescription amphetamines among adults, further study into the association between stimulants and adverse events such as trichotillomania is needed.

Agonist-like pharmacotherapy for stimulant dependence: preclinical, human laboratory, and clinical studies

A variety of natural and synthetic agents have long been used for stimulant properties, with nontherapeutic use producing multiple waves of stimulant abuse and dependence. The multitude of effects of stimulants exist on continua, and accordingly, here we characterize stimulant abuse/dependence and candidate pharmacotherapies in this manner. Behavioral therapy and medications have been investigated for treatment of stimulant abuse/dependence. Effectiveness of some behavioral interventions has been demonstrated. Most medications studied have been found to lack efficacy. However, an expanding literature supports use of agonist-like medications to treat stimulant abuse/dependence, a strategy effective for nicotine and opiate dependence. The agonist-like conceptualization for stimulant dependence posits that medications with properties similar to that of the abused drug, but possessing lesser abuse liability, will normalize neurochemistry and stabilize behavior, thus reducing drug use. Data suggest use of a range of medications, from l-dopa/carbidopa to amphetamine preparations, depending on the severity of use. This report reviews preclinical, human laboratory, and clinical trial data supporting the agonist-like approach, including risks and benefits. Future directions for development of agonist-like medications are also discussed.

White-matter abnormalities in brain during early abstinence from methamphetamine abuse

BACKGROUND

Previous studies revealed microstructural abnormalities in prefrontal white matter and corpus callosum of long-term abstinent chronic methamphetamine abusers. In view of the importance of the early abstinence period in treatment retention, we compared 23 methamphetamine-dependent subjects abstinent from methamphetamine for 7-13 days with 18 healthy comparison subjects. As certain metabolic changes in the brain first manifest after early abstinence from methamphetamine, it is also possible that microstructural white-matter abnormalities are not yet present during early abstinence.

METHODS

Using diffusion tensor imaging at 1.5 T, fractional anisotropy (FA) was measured in prefrontal white matter at four inferior-superior levels parallel to the anterior commissure-posterior commissure (AC-PC) plane. We also sampled FA in the corpus callosum at the midline and at eight bilateral, fiber-tract sites in other regions implicated in effects of methamphetamine.

RESULTS

The methamphetamine group exhibited lower FA in right prefrontal white matter above the AC-PC plane (11.9% lower; p = 0.007), in midline genu corpus callosum (3.9%; p = 0.019), in left and right midcaudal superior corona radiata (11.0% in both hemispheres, p's = 0.020 and 0.016, respectively), and in right perforant fibers (7.3%; p = 0.025). FA in left midcaudal superior corona radiata was correlated with depressive and generalized psychiatric symptoms within the methamphetamine group.

CONCLUSIONS

The findings support the idea that methamphetamine abuse produces microstructural abnormalities in white matter underlying and interconnecting prefrontal cortices and hippocampal formation. These effects are already present during the first weeks of abstinence from methamphetamine and are linked to psychiatric symptoms assessed during this period.

Methamphetamine self-administration is associated with persistent biochemical alterations in striatal and cortical dopaminergic terminals in the rat

Methamphetamine (meth) is an illicit psychostimulant that is abused throughout the world. Repeated passive injections of the drug given in a single day or over a few days cause significant and long-term depletion of dopamine and serotonin in the mammalian brain. Because meth self-administration may better mimic some aspects of human drug-taking behaviors, we examined to what extent this pattern of drug treatment might also result in damage to monoaminergic systems in the brain. Rats were allowed to intravenously self-administer meth (yoked control rats received vehicle) 15 hours per day for 8 days before being euthanized at either 24 hours or at 7 and 14 days after cessation of drug taking. Meth self-administration by the rats was associated with a progressive escalation of daily drug intake to 14 mg/kg per day. Animals that self-administered meth exhibited dose-dependent decreases in striatal dopamine levels during the period of observation. In addition, there were significant reductions in the levels of striatal dopamine transporter and tyrosine hydroxylase proteins. There were also significant decreases in the levels of dopamine, dopamine transporter, and tyrosine hydroxylase in the cortex. In contrast, meth self-administration caused only transient decreases in norepinephrine and serotonin levels in the two brain regions, with these values returning to normal at seven days after cessation of drug taking. Importantly, meth self-administration was associated with significant dose-dependent increases in glial fibrillary acidic protein in both striatum and cortex, with these changes being of greater magnitude in the striatum. These results suggest that meth self-administration by rats is associated with long-term biochemical changes that are reminiscent of those observed in post-mortem brain tissues of chronic meth abusers.

Paradoxical simultaneous occurrence of amphetamine-induced conditioned taste aversion and conditioned place preference with the same single drug injection: a new "pre- and post-association" experimental paradigm

The paradoxical phenomenon of co-existing physically aversive and psychologically rewarding effects of drugs is a crucial issue for drug addiction. The present study employed a new experimental paradigm to test whether the rewarding and aversive properties of amphetamine (AMPH) can exist simultaneously. Rats were given a 15 min period of exposure to saccharin injected with 0.15M NaCl or 1.5mg/kg AMPH and then were confined to one compartment of a test box for 30 min. After three paired and unpaired cycles, the aversive and rewarding effects were assessed. A reduction in consumption of the paired flavored solution provided evidence of avoidance while preference for the AMPH injection context provided evidence of rewarding effects. The present findings demonstrate that the development of AMPH-induced rewarding and aversive effects depends on the particular behavioral conditions and support both the task-dependent drug effects hypothesis and the reward comparison hypothesis. The formation of associations with stimuli that comes before (pre) vs. after (post) the unconditioned stimulus and the role of the dopaminergic system in such associations are discussed.

An unusual suicidal death by automobile antenna: a case report

Worldwide, over one million people commit suicide every year. In the United States, the majority of these cases consist of gunshot wounds, hangings, and drug overdoses. Nevertheless, on rare occasions will individuals exhibit extraordinary creativity in how they decide to end their lives.

A decomposing white male was found lying beside his vehicle; blood was noted on the hood. Beneath the deceased's head was a copious amount of blood, and clutched within his right hand was a vehicle radio antenna. A search of a nearby storage shed uncovered drug paraphernalia and in the decedent's bedroom were two handwritten suicide notes. At autopsy, a defect was discovered in the right posterior oropharnyx. Immediately posterior to this injury were fractures of the right transverse processes and interarticular portions of the C2 and C3 vertebrae, with perforation of the right vertebral artery. No other injuries were noted externally. Radiographs of the head and neck showed no evidence of a projectile, and no corresponding exit defect was identified. Postmortem toxicology was positive for cocaine and methamphetamine.

We present a case report of a man under the influence of cocaine and methamphetamine employing a car antenna to cause self-inflicted, intraoral penetrating trauma to the cervical spine and right vertebral artery, resulting in exsanguination and his subsequent death.

Mortality among amphetamine users: a systematic review of cohort studies

AIMS

To report the results of a comprehensive literature search of studies of mortality among people who use amphetamines.

DESIGN AND SETTING

Three electronic databases were searched (EMBASE, Medline and PsycINFO) and "grey" literature was located. Shortlists of papers were circulated to experts to ascertain whether any important papers had been missed. Papers were hand-searched to retrieve any additional relevant articles.

MEASUREMENTS

Studies meeting inclusion criteria were prospective cohort studies examining mortality risk among dependent and problematic amphetamine users. Crude mortality rates (CMR/100PY) and standardised mortality ratios (SMRs) were the primary outcome measures considered. Data on overall mortality, and rates for specific causes of death, were of interest.

FINDINGS

2187 articles and 9 grey literature sources were obtained. After thorough review, 72 articles were identified as reporting on amphetamine-related mortality, 7 provided data from cohort studies of users. An additional study of Swedish military conscripts was identified by the authors during correspondence with other researchers. The geographic spread of cohorts was restricted to high income countries with the exception of one Thai study; reporting of standard parameters in mortality studies was often sparse. The estimated CMRs ranged from 0 in Australia to 2.95 (1.46-4.59) in Thailand. The Czech cohort reported the only SMR: 6.22 overall, males: 5.87, females: 7.84.

CONCLUSIONS

Given the widespread use of amphetamines, the known non-fatal adverse effects of use and the mortality rates reported here, cohort studies investigating the morbidity and mortality associated with such drug use should be a research priority.

Substance misuse and early psychosis

OBJECTIVE

This paper sought to review current knowledge about the relationship between substance misuse and early psychosis.

METHODS

A literature search was conducted using Medline and restricting the search to articles after 1996. Additional articles were sourced from reference lists of relevant articles.

RESULTS

There is a high prevalence of substance misuse among persons with early psychosis, with cannabis and alcohol featuring prominently. Substance misuse is associated with earlier onset and possibly more positive symptoms, although apparently not with greater cognitive impairment. Cannabis appears to confer an increased likelihood of developing schizophrenia in biologically vulnerable individuals. Amphetamines also cause psychosis which may become chronic, although specific vulnerability to this effect is less well established. Many cases of so-called 'drug-induced psychosis' become diagnosed as schizophrenia in later years. Specific intervention programs report positive outcomes with regard to substance misuse and the course of psychosis.

CONCLUSIONS

Substance misuse should always be assessed in this patient group, bearing in mind the potential interactive causes of psychopathology. Intervention is of value in improving outcomes.

Methamphetamine- and trauma-induced brain injuries: comparative cellular and molecular neurobiological substrates

The use of methamphetamine (METH) is a growing public health problem, because its abuse is associated with long-term biochemical and structural effects on the human brain. Neurodegeneration is often observed in humans, because of mechanical injuries (e.g., traumatic brain injury [TBI]) and ischemic damage (strokes). In this review, we discuss recent findings documenting the fact that the psychostimulant drug METH can cause neuronal damage in several brain regions. The accumulated evidence from our laboratories and those of other investigators indicates that acute administration of METH leads to activation of calpain and caspase proteolytic systems. These systems are also involved in causing neuronal damage secondary to traumatic and ischemic brain injuries. Protease activation is accompanied by proteolysis of endogenous neuronal structural proteins (alphaII-spectrin protein and microtubule-associated protein-tau), evidenced by the appearance of their breakdown products after these injuries. When taken together, these observations suggest that METH exposure, like TBI, can cause substantial damage to the brain by causing both apoptotic and necrotic cell death in the brains of METH addicts who use large doses of the drug during their lifetimes. Finally, because METH abuse is accompanied by functional and structural changes in the brain similar to those in TBI, METH addicts might experience greater benefit if their treatment involved greater emphasis on rehabilitation in conjunction with potential neuroprotective pharmacological agents such as calpain and caspase inhibitors similar to those used in TBI.

Methamphetamine induces dopamine D1 receptor-dependent endoplasmic reticulum stress-related molecular events in the rat striatum

Methamphetamine (METH) is an illicit toxic psychostimulant which is widely abused. Its toxic effects depend on the release of excessive levels of dopamine (DA) that activates striatal DA receptors. Inhibition of DA-mediated neurotransmission by the DA D1 receptor antagonist, SCH23390, protects against METH-induced neuronal apoptosis. The initial purpose of the present study was to investigate, using microarray analyses, the influence of SCH23390 on transcriptional responses in the rat striatum caused by a single METH injection at 2 and 4 hours after drug administration. We identified 545 out of a total of 22,227 genes as METH-responsive. These include genes which are involved in apoptotic pathways, endoplasmic reticulum (ER) stress, and in transcription regulation, among others. Of these, a total of 172 genes showed SCH23390-induced inhibition of METH-mediated changes. Among these SCH23390-responsive genes were several genes that are regulated during ER stress, namely ATF3, HSP27, Hmox1, HSP40, and CHOP/Gadd153. The secondary goal of the study was to investigate the role of DA D1 receptor stimulation on the expression of genes that participate in ER stress-mediated molecular events. We thus used quantitative PCR to confirm changes in the METH-responsive ER genes identified by the microarray analyses. We also measured the expression of these genes and of ATF4, ATF6, BiP/GRP78, and of GADD34 over a more extended time course. SCH23390 attenuated or blocked METH-induced increases in the expression of the majority of these genes. Western blot analysis revealed METH-induced increases in the expression of the antioxidant protein, Hmox1, which lasted for about 24 hours after the METH injection. Additionally, METH caused DA D1 receptor-dependent transit of the Hmox1 regulator protein, Nrf2, from cytosolic into nuclear fractions where the protein exerts its regulatory functions. When taken together, these findings indicate that SCH23390 can provide protection against neuronal apoptosis by inhibiting METH-mediated DA D1 receptor-mediated ER stress in the rat striatum. Our data also suggest that METH-induced toxicity might be a useful model to dissect molecular mechanisms involved in ER stress-dependent events in the rodent brain.

Drugs and violent death: comparative toxicology of homicide and non-substance toxicity suicide victims

AIMS

To determine the comparative toxicology of death by homicide and suicide by means other than substance toxicity.

DESIGN

Cross-sectional (autopsy reports).

SETTING

Sydney, Australia.

CASES

A total of 1723 cases of violent death were identified, comprising 478 homicide (HOM) cases and 1245 non-substance toxicity suicide (SUI) cases.

FINDINGS

Substances were detected in 65.5% of cases, and multiple substances in 25.8%, with no group differences. Illicit drugs were detected in 23.9% of cases, and multiple illicit in 5.3%. HOM cases were significantly more likely to have an illicit drug [odds ratio (OR) 2.09] and multiple illicits (OR 2.94), detected, HOM cases being more likely to have cannabis (OR 2.39), opioids (OR 1.53) and psychostimulants (OR 1.59) present. HOM cases were, however, significantly less likely to have benzodiazepines (OR 0.53), antidepressants (OR 0.22) and antipsychotics (OR 0.23) present. Alcohol was present in 39.6% of cases (median blood alcohol concentration = 0.12), with no group difference in prevalence.

CONCLUSIONS

The role drugs play in premature death extends far beyond overdose and disease, with illicit drugs associated strongly with homicide.

Effects of cannabinoid CB1 receptor antagonist rimonabant in consolidation and reconsolidation of methamphetamine reward memory in mice

RATIONALE

Previous studies have shown that cannabinoid CB1 receptors play an important role in specific aspects of learning and memory, yet there has been no systematic study focusing on the involvement of cannabinoid CB1 receptors in methamphetamine-related reward memory.

OBJECTIVES

The purpose of this study was to examine whether rimonabant, a cannabinoid CB1 receptor antagonist, would disrupt the consolidation and reconsolidation of methamphetamine-related reward memory, using conditioned place preference paradigm (CPP).

MATERIALS AND METHODS

Separate groups of male Kunming mice were trained to acquire methamphetamine CPP. Vehicle or rimonabant (1 mg/kg or 3 mg/kg, i.p.) was given at different time points: immediately after each CPP training session (consolidation), 30 min before the reactivation of CPP (retrieval), or immediately after the reactivation of CPP (reconsolidation). Methamphetamine CPP was retested 24 h and 1 and 2 weeks after rimonabant administration.

RESULTS

Rimonabant at doses of 1 and 3 mg/kg significantly inhibited the consolidation of methamphetamine CPP. Only high-dose rimonabant (3 mg/kg) disrupted the retrieval and reconsolidation of methamphetamine CPP. Rimonabant had no effect on methamphetamine CPP in the absence of methamphetamine CPP reactivation.

CONCLUSIONS

Our findings suggest that cannabinoid CB1 receptors play a major role in methamphetamine reward memory, and cannabinoid CB1 receptor antagonists may be a potential pharmacotherapy to manage relapse associated with drug-reward-related memory.

Patterns of methamphetamine use and symptoms of depression among young adults in northern Thailand

INTRODUCTION

Depression often co-occurs with amphetamine type stimulant use and can negatively impact drug treatment outcomes. Understanding the temporal relationship between depressive symptoms and methamphetamine use can further inform both treatment and mental health options.

METHODS

Methamphetamine users aged 18-25 years were enrolled in a 12-month randomized behavioral trial in Thailand. Questionnaires were administered every 3 months and included information on substance use and depressive symptoms. Pattern of methamphetamine use during follow-up was characterized into four groups: early cessation, late cessation, relapse and persistent use. Multinomial logistic regression was used to determine the impact of baseline depressive symptoms (CES-D score and % > or =22) on patterns of methamphetamine use during follow-up. Linear and logistic regression was used to determine the impact of patterns of methamphetamine use on depressive symptoms at the end of the trial.

RESULTS

No association was found between baseline depressive symptoms and subsequent patterns of methamphetamine use. A significant relationship was found between patterns of methamphetamine use and ensuing depressive symptoms, with those achieving cessation experiencing lower levels of depressive symptoms.

DISCUSSION

Many symptoms of depression may resolve with cessation or reduction in methamphetamine use. Clinical and community-based efforts that facilitate drug users' attempts to stop using drugs should be supported as they may contribute to positive cessation outcomes and help to improve overall mental health.

Health consequences of illegal drug use

PURPOSE OF REVIEW

The aim of this article is to review recent research on the health consequences of illegal drug use and possible risk factors, with a particular focus on prospective evidence.

RECENT FINDINGS

Mortality studies have revealed qualitative and quantitative changes in causes of death among heroin and injecting drug users (IDUs), probably due to increasing exposure to harm reduction programs, the introduction of highly active antiretroviral therapy (HAART), the aging of drug users, and rising concurrent use of illegal drugs and prescription drugs. For morbidity, nonfatal overdose is still one of the most important concerns; likewise the higher prevalence of hepatitis C among non-IDUs and hepatitis A, B, C coinfection. Cannabis use has been consistently reported to be associated with the emergence of psychotic symptoms, yet that seems not to be the case for anxiety and depressive disorders. Use of 3,4 methylenedioxymethamphetamine (MDMA) has been linked with short-term negative effects on cognitive performance (i.e. visual memory). A series of longitudinal studies have shown enduring unfavorable effects of prenatal cocaine and marijuana exposure on children's physical, cognitive, and language development.

SUMMARY

Prospective evidence on illegal drug use in particular subpopulations may be needed to better understand health problems among users at different life stages and the possible long-term effects.

Methamphetamine toxicity and messengers of death

Methamphetamine (METH) is an illicit psychostimulant that is widely abused in the world. Several lines of evidence suggest that chronic METH abuse leads to neurodegenerative changes in the human brain. These include damage to dopamine and serotonin axons, loss of gray matter accompanied by hypertrophy of the white matter and microgliosis in different brain areas. In the present review, we summarize data on the animal models of METH neurotoxicity which include degeneration of monoaminergic terminals and neuronal apoptosis. In addition, we discuss molecular and cellular bases of METH-induced neuropathologies. The accumulated evidence indicates that multiple events, including oxidative stress, excitotoxicity, hyperthermia, neuroinflammatory responses, mitochondrial dysfunction, and endoplasmic reticulum stress converge to mediate METH-induced terminal degeneration and neuronal apoptosis. When taken together, these findings suggest that pharmacological strategies geared towards the prevention and treatment of the deleterious effects of this drug will need to attack the various pathways that form the substrates of METH toxicity.

Changes and predictors of change in the physical health status of heroin users over 24 months

AIMS

(i) To describe the course of physical health among the ATOS cohort over 24 months; and (ii) to examine the effects of treatment, drug use patterns and social and psychological factors on health status over 24 months.

DESIGN

Longitudinal cohort.

SETTING

Sydney, Australia.

PARTICIPANTS

A total of 615 heroin users recruited for the Australian Treatment Outcome Study (ATOS).

FINDINGS

The general health of the cohort improved significantly over 24 months. Significant predictors of poor health over 24 months were: being older, being female, past month heroin, other opiate and tobacco use, past month unemployment and current major depression. Spending a greater proportion of time in residential rehabilitation (RR) was associated with better health over 24 months. No other treatment factors demonstrated a significant, independent relationship with health.

CONCLUSIONS

The physical health of dependent heroin users is affected by drug use and psychosocial problems. RR treatment appears to be particularly beneficial to the health of heroin users, suggesting the importance of a comprehensive approach to improving health among this group.

mGluR5 antagonism attenuates methamphetamine reinforcement and prevents reinstatement of methamphetamine-seeking behavior in rats

Addiction to methamphetamine is a significant public health problem, and there are currently no pharmacological agents that are approved for the treatment of addiction to this powerful psychostimulant. Chronic methamphetamine use leads to cognitive dysfunction as well as numerous psychiatric, neurological, and cardiovascular complications. There is a growing body of literature implicating an important role for glutamate neurotransmission in psychostimulant addiction. In the present study, we examined the effects of the selective type 5 metabotropic glutamate receptor (mGluR5) antagonist 3-((2-methyl-1,3-thiazol-4-yl)ethynyl)pyridine (MTEP) on intravenous self-administration of methamphetamine and reinstatement of methamphetamine-seeking behavior. Adult male Sprague-Dawley rats were trained to respond for intravenous methamphetamine (0.1 or 0.2 mg/kg per infusion) or food pellets and were subsequently administered vehicle or MTEP (0.3-3 mg/kg) before drug or food self-administration on a fixed-ratio 1 (FR1) schedule of reinforcement or a progressive ratio (PR) schedule of reinforcement. We also examined the effects of vehicle or MTEP (0.3-3 mg/kg) on cue- and drug-induced reinstatement of methamphetamine-seeking behavior as well as cue-induced reinstatement of food-seeking behavior. Our results show that MTEP dose dependently reduced the reinforcing effects of methamphetamine under FR1 and PR schedules of reinforcement without altering overall responding for food. MTEP also dose dependently prevented cue- and drug-induced reinstatement of methamphetamine-seeking behavior, but did not alter cue-induced reinstatement of food-seeking behavior. Together, these results indicate that mGluR5 receptors mediate methamphetamine reinforcement and methamphetamine-seeking behavior, and that pharmacological inhibitors of mGluR5 receptor function may represent a novel class of potential therapeutic agents for the treatment of methamphetamine addiction.

Methamphetamine induces long-term alterations in reactivity to environmental stimuli: correlation with dopaminergic and serotonergic toxicity

Methamphetamine (METH) abuse is known to induce persistent cognitive and behavioral abnormalities, in association with alterations in serotonin (5-HT) and dopamine (DA) systems, yet the neurobiological mechanisms underpinning this link are elusive. Thus, in the present study we analyzed the long-term impact of an acute toxic regimen of METH (4 mg/kg, subcutaneous x 4 injections, 2 h apart) on the reactivity of adult male rats to environmental stimuli, and correlated it to toxicity on 5-HT and DA innervations. Two separate groups of METH-injected rats were compared to their saline-treated controls on object exploration and startle paradigms, at either 1 or 3 weeks after METH administration, respectively. Twenty-four hours after behavioral testing, animals were sacrificed, and the neurotoxic effects of the METH schedule on DA and 5-HT terminals were measured through immunochemical quantification of their transporters (DAT and 5-HTT). At both 1 and 3 weeks after treatment, METH-injected rats exhibited a significant decline in the number of exploratory approaches to unfamiliar objects, which was significantly correlated with a parallel reduction in DAT immunoreactivity (IR) in the nucleus accumbens (NAc) core. Furthermore, METH-treated rats displayed a significant enhancement in startle magnitude after 3 (but not 1) weeks, which was inversely correlated with a decrement in 5-HTT IR in the Cg3 infralimbic area of prefrontal cortex. Our results suggest that METH induces long-term changes in object exploration and startle responsiveness, which may be respectively underpinned by reductions in DAergic and 5-HTergic brain terminals.

A double-blind, placebo-controlled trial of modafinil (200 mg/day) for methamphetamine dependence

AIM

To examine the safety and efficacy of modafinil (200 mg/day) compared to placebo in the treatment of methamphetamine dependence and to examine predictors of post-treatment outcome.

PARTICIPANTS AND DESIGN

Eighty methamphetamine-dependent subjects in Sydney, Australia were allocated randomly to modafinil (200 mg/day) (n = 38) or placebo (n = 42) under double-blind conditions for 10 weeks with a further 12 weeks post-treatment follow-up.

MEASURES

Comprehensive drug use data (urine specimens and self-report) and other health and psychosocial data were collected weekly during treatment and research interviews at baseline, week 10 and week 22.

RESULTS

Treatment retention and medication adherence were equivalent between groups. There were no differences in methamphetamine abstinence, craving or severity of dependence. Medication-compliant subjects tended to provide more methamphetamine-negative urine samples over the 10-week treatment period (P = 0.07). Outcomes were better for methamphetamine-dependent subjects with no other substance dependence and those who accessed counselling. There were statistically significant reductions in systolic blood pressure (P = 0.03) and weight gain (P = 0.05) in modafinil-compliant subjects compared to placebo. There were no medication-related serious adverse events. Adverse events were generally mild and consistent with known pharmacological effects.

CONCLUSIONS

Modafinil demonstrated promise in reducing methamphetamine use in selected methamphetamine-dependent patients. The study findings support definitive trials of modafinil in larger multi-site trials.