Associations between methamphetamine use, psychiatric comorbidities and treatment outcome in two inpatient rehabilitation centers

Neuronal biomarkers as potential therapeutic targets for drug addiction related to sex differences in the brain: Opportunities for personalized treatment approaches

Biological sex disparities manifest at various stages of drug addiction, including craving, substance abuse, abstinence, and relapse. These discrepancies are underpinned by notable distinctions in neurobiological substrates, encompassing brain structures, functions, and neurotransmitter systems implicated in drug addiction. Neuronal biomarkers, such as neurotransmitters, signaling proteins, and genes may be associated with the diagnosis, prognosis, and treatment outcomes in both biological sexes afflicted by drug abuse. Sex differences in the neural reward system, mainly through dopaminergic transmission during drug abuse, can be attributed to modifications in neurotransmitter systems and signaling pathways. This results in distinct patterns of neural activation and responsiveness to addictive substances in males and females. Sex hormones, the estrus/menstrual cycle, and cerebral neurochemistry contribute to the progression of psychological and physiological dependence in both male and female individuals grappling with addiction. Moreover, the alteration of sex hormone balance and neurotransmitter release plays a pivotal role in substance use disorders, subsequently modulating cognitive functions pertinent to reward, including memory formation, decision-making, and locomotor activity. Comparative investigations reveal distinctions in brain region volume, gene expression, neuronal firing, and circuitry in substance use disorders affecting individuals of both biological sexes. This review examines prevalent substance use disorders to elucidate the impact of sex hormones as therapeutic biomarkers on the mesocorticolimbic neurotransmitter systems via diverse mechanisms within the addicted brain. We underscore the imperative necessity of considering these variations to gain a deeper comprehension of addiction mechanisms and potentially discern sex-specific neuronal biomarkers for tailored therapeutic interventions.

Modeling methamphetamine use disorder in mammals: Sex differences in behavioral, biochemical, and transcriptional consequences

Methamphetamine (METH) is the most commonly misused amphetamine-type stimulant throughout the globe. METH is very rewarding, and its misuse can lead to a diagnosis of METH use disorder (MUD). Although METH use is observed in both sexes, there are, however, reported differences in the clinical manifestations of METH use and its consequences. These observations indicate the need for more research on the long-term sex-dependent consequences of METH taking in both preclinical and clinical settings. In effect, sex is a biological variable that can impact conclusions drawn from various basic and clinical studies. Thus, the present chapter provides a succinct review of the current state of the research on METH and its sex-associated consequences. In addition to behavioral and cognitive aspects of METH use, we discuss METH-induced changes in neurotransmitter systems and structures in the brain. Thus, the book chapter serves to highlight the significance of sex as a critical element that needs to be considered during discussions of novel therapeutic approaches to MUD.

Modeling methamphetamine use disorder and relapse in animals: short- and long-term epigenetic, transcriptional., and biochemical consequences in the rat brain

Methamphetamine use disorder (MUD) is a neuropsychiatric disorder characterized by binge drug taking episodes, intervals of abstinence, and relapses to drug use even during treatment. MUD has been modeled in rodents and investigators are attempting to identify its molecular bases. Preclinical experiments have shown that different schedules of methamphetamine self-administration can cause diverse transcriptional changes in the dorsal striatum of Sprague-Dawley rats. In the present review, we present data on differentially expressed genes (DEGs) identified in the rat striatum following methamphetamine intake. These include genes involved in transcription regulation, potassium channel function, and neuroinflammation. We then use the striatal data to discuss the potential significance of the molecular changes induced by methamphetamine by reviewing concordant or discordant data from the literature. This review identified potential molecular targets for pharmacological interventions. Nevertheless, there is a need for more research on methamphetamine-induced transcriptional consequences in various brain regions. These data should provide a more detailed neuroanatomical map of methamphetamine-induced changes and should better inform therapeutic interventions against MUD.

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.

Stimulant use among patients in opioid treatment settings: Provider perspectives

INTRODUCTION

Methadone maintenance therapy (MMT) has been a pillar of opioid addiction treatment. Opioid treatment programs (OTPs) have been faced with an escalating threat of stimulant use and related overdose deaths among patients. We know little about how providers currently address stimulant use while maintaining treatment for opioid use disorder.

METHODS

We conducted 5 focus groups with 36 providers (n = 11 prescribers; 25 behavioral health staff), and collected an additional 46 surveys (n = 7 prescribers; 12 administrators; 27 behavioral health staff). Questions focused on perceptions of patient stimulant use and interventions. We applied inductive analysis to identify themes relevant to identification of stimulant use, use trends, intervention approaches, and perceived needs to improve care.

RESULTS

Providers indicated a trend of rising stimulant use among patients, especially those experiencing homelessness or comorbid health conditions. They reported a range of approaches to patient screening and intervention, including medication and harm reduction, improving treatment engagement, increasing level of care, and providing incentives. Providers expressed less agreement as to which of these interventions were effective, and though providers saw stimulant use as a common and severe problem, they reported little problem recognition and interest in treatment from their patients. A particular concern of providers was the prevalence and danger of synthetic opioids, such as fentanyl. They sought more research and resources to identify effective interventions and medications to address these issues. Also notable was an interest in contingency management (CM) and use of reinforcements/rewards to encourage stimulant use reduction.

CONCLUSION

Providers face challenges in treating patients who use both opioids and stimulants. Although methadone is available to treat opioid use, no such "silver bullet" exists for stimulant use disorder. The rise in stimulant and synthetic opioid (e.g., fentanyl) combination products is presenting an extraordinary challenge for providers whose patients are at unprecedented risk for overdose. Providing OTPs with more resources to address polysubstance use is critical. Existing research indicates strong support for CM in OTPs, but providers reported regulatory and financial barriers to implementation. Further research should develop effective interventions that are accessible to providers in OTPs.

Sex-Dependent Alterations in the mRNA Expression of Enzymes Involved in Dopamine Synthesis and Breakdown After Methamphetamine Self-Administration

Sex differences have been reported in methamphetamine (METH) use disorder in humans and in animal models of METH exposure. Specifically, animals that self-administer METH show sex-related dissimilarities in dopamine (DA) metabolism. To better understand the molecular bases for the differences in DA metabolism, we measured the levels of mRNAs of enzymes that catalyze DA synthesis and breakdown in the prefrontal cortex (PFC), nucleus accumbens (NAc), dorsal striatum (dSTR), and hippocampus (HIP) of rats that had self-administered METH. There were significant sex differences in control rats, with males having higher basal levels of Th in the PFC and dSTR, Ddc in the NAc, and MaoB in the HIP. In contrast, female controls showed higher basal levels of Comt in the HIP. Male and female METH SA rats also showed some distinct responses to the drug. Specifically, female METH rats exhibited increased expression of Ddc and MaoB, whereas male METH animals showed higher levels of Comt mRNA in the PFC compared to their respective controls. In the NAc, male METH rats displayed decreased Th and Ddc mRNA levels. Together, our results identified sex-dependent and region-specific changes in the mRNA expression of several enzymes involved in DA synthesis and breakdown in response to METH SA, with the majority of differences being observed in the mesocorticolimbic dopaminergic system. These findings are of significant translational importance providing further support for the inclusion of sex as an important variable when planning and evaluating therapeutic interventions against METH use disorder in human clinical studies.

Sex differences in methamphetamine use disorder perused from pre-clinical and clinical studies: Potential therapeutic impacts

Methamphetamine (METH) use, and misuse are associated with severe socioeconomic consequences. METH users develop tolerance, lose control over drug taking behaviors, and suffer frequent relapses even during treatment. The clinical course of METH use disorder is influenced by multifactorial METH-induced effects on the central and peripheral nervous systems. Although these METH-induced consequences are observed in humans of all ages, races, and sexes, sexual dimorphism in these outcomes have been observed in both pre-clinical and clinical settings. In this review, we have provided a detailed presentation of the sex differences reported in human and animal studies. We have therefore presented data that identified the influences of sex on METH pharmacokinetics, METH-induced changes in behaviors, cognitive processes, structural changes in the brain, and the effects of the drug on neurotransmitter systems and molecular mechanisms. Finally, we highlighted the potential significance of sex as a critical variable that should be considered when planning the development of new pharmacotherapeutic approaches against MEH use disorder in humans.

Sex-Specific Alterations in Dopamine Metabolism in the Brain after Methamphetamine Self-Administration

Methamphetamine (METH) use disorder affects both sexes, with sex differences occurring in behavioral, structural, and biochemical consequences. The molecular mechanisms underlying these differences are unclear. Herein, we used a rat model to identify potential sex differences in the effects of METH on brain dopaminergic systems. Rats were trained to self-administer METH for 20 days, and a cue-induced drug-seeking test was performed on withdrawal days 3 and 30. Dopamine and its metabolites were measured in the prefrontal cortex (PFC), nucleus accumbens (NAc), dorsal striatum (dSTR), and hippocampus (HIP). Irrespective of conditions, in comparison to females, male rats showed increased 3,4-dihydroxyphenylalanine (DOPA) in the PFC, dSTR, and HIP; increased cys-dopamine in NAc; and increased 3,4-dihydroxyphenylethanol (DOPET) and 3,4-dihydroxyphenylacetic acid (DOPAC) in dSTR. Males also showed METH-associated decreases in DA levels in the HIP but increases in the NAc. Female rats showed METH-associated decreases in DA, DOPAL, and DOPAC levels in the PFC but increases in DOPET and DOPAC levels in the HIP. Both sexes showed METH-associated decreases in NAc DA metabolites. Together, these data document sex differences in METH SA-induced changes in DA metabolism. These observations provide further support for using sex as an essential variable when discussing therapeutic approaches against METH use disorder in humans.

Psychiatric Comorbidity and Psychopathology of Methamphetamine Users—Are There Gender Differences?

Methamphetamine use disorder is associated with severe psychiatric symptoms and psychosocial problems. Women seem to be more affected than men. Therefore, this study examined psychiatric comorbidities and psychopathology, drug use patterns, and treatment outcomes in women addicted to methamphetamine compared to men. Data on methamphetamine-dependent inpatients were collected in two centers specialized for addiction treatment at admission (T0) and discharge (T1, after treatment for 24 weeks). Sociodemographic and clinical measures were collected with the semi-structured clinical interview I at baseline; the self-reported standardized questionnaire (SCL-90-R) was administered at admission and discharge and after 24 weeks. During the entire treatment procedure, treatment relevant aspects were monitored. Out of all 108 treatment-seeking participants (86 men, 22 women), 64 completed the study (51 men, 13 women; drop-out rate: 40.7% (n = 44)). Methamphetamine-dependent women used other stimulants more often than men, while men used hallucinogens significantly more frequently than women. Female inpatients differed significantly from men in various sociodemographic variables (e.g., having children, single parenting) and were significantly more often affected by current (p < 0.001) and lifetime mental stress disorders (p < 0.001), as well as specific psychiatric disorders (p < 0.001) (e.g., posttraumatic stress disorder). At discharge, mental symptoms decreased significantly in men but not in women. Both before and after treatment, women seem to be more vulnerable to psychiatric comorbidities and psychopathologic symptoms compared to men. Although this study only provides preliminary data on gender-specific characteristics of methamphetamine-dependent patients and their treatment, it seems appropriate to discuss the development of gender-specific treatment options. Further studies in this field are needed.

All-cause and suicide mortality among people with methamphetamine use disorder: a nation-wide cohort study in Taiwan

BACKGROUND AND AIMS

Although methamphetamine use is a serious public health problem, large-scale cohort studies assessing methamphetamine-related mortality are scant. This study investigated all-cause mortality and suicide methods in people with methamphetamine use disorder.

DESIGN

A cohort record-linkage study using data from Taiwan's National Health Research Institute Database (NHIRD) linked to Taiwan's National Death Certification System.

SETTING

Taiwan.

PARTICIPANTS

A total of 23 248 individuals with methamphetamine use disorder between 1 January 2001 and 31 December 2005.

MEASUREMENTS

The outcome variables included mortality rates and standardized mortality ratios (SMRs) for all causes of death and for each suicide method.

FINDINGS

Compared with the general population, the current cohort had an increased all-cause mortality (SMR = 5.4), with the SMR for unnatural causes (14.8) higher than that for natural causes (7.5). Among all causes of death, suicide had the highest SMR (16.3), followed by neurological diseases (9.7). Among the methods of choice for suicide, drug overdose had the highest SMR (24.9). The incidence of charcoal burning and hanging was significantly higher in men and that of jumping from a high place was significantly higher in women.

CONCLUSION

People in Taiwan with methamphetamine use disorder appear to have a significantly increased all-cause mortality rate compared with the general population, with suicide having the highest contribution, particularly suicide via drug overdose. The methods of choice for suicide revealed distinct patterns between men and women.

Predictors of length of treatment, discharge reason, and re-admission to Aboriginal alcohol and other drug residential rehabilitation services in New South Wales, Australia

INTRODUCTION

Aboriginal clients accessing Aboriginal community-controlled residential alcohol and other drug rehabilitation services in New South Wales, Australia believe they have better outcomes due to culturally appropriate care. However, there is a paucity of published treatment outcome data. This study aims to identify predictors of treatment outcomes based on client characteristics at intake.

METHODS

A cross-sectional, retrospective, observational study of 2326 admissions to six services between January 2011 and December 2016. The outcomes were: (i) leaving treatment early; (ii) self-discharge or house discharge (by staff); and (iii) re-admission within two years. The predictors examined were Aboriginal status, age, justice system referral and primary substance of concern. Competing risk and Poisson regression analyses were used to identify trends in the data.

RESULTS

The mean age of clients was 33 years, and the majority (56%) stayed at least 6 weeks. Aboriginal clients whose primary substance of concern was stimulants were almost eight times more likely to re-admitted within 2 years than other clients (risk ratio 7.91; P < 0.001). Aboriginal clients who were also referred from justice were more likely to self-discharge (risk ratio 1.87; P < 0.001). Furthermore, Aboriginal clients who were aged older than 30 were less likely to have a re-admission (risk ratio 0.32; P ≤ 0.001).

DISCUSSION AND CONCLUSIONS

This study showed client characteristics that are predictive of harmful outcomes include age under 30, justice client, primary substance of use and their interactions. Future research could build on these results to aid ongoing development of residential rehabilitation programs for Aboriginal peoples.

12- and 18-month follow-up after residential treatment of methamphetamine dependence: Influence of treatment drop-out and different treatment concepts

This study investigates the effects of two different residential treatments and of treatment drop-out in a German methamphetamine (MA) dependent sample. 108 subjects from two addiction treatment concepts were recruited at treatment begin and followed-up at 12 (T2) and 18 (T3) months after treatment. Based on follow-up samples (n = 38 at T2, n = 25 at T3), 77.1% at T2 and 68.0% at T3 were MA abstinent. Classifying everyone, who did not participate at follow-ups as having had a relapse, showed MA-abstinence rates of 25.0% (at T2) and 15.7% (at T3). There was no difference in MA-use between treatment conditions nor between treatment completers and drop-outs. Having injected any substance predicted MA-use at T2 (p = .03). The median time of relapse was 1.5 days after hospital release. Depression scores at T2 predicted MA-use at T3 (p = .02). T2 participants that dropped out of treatment had higher craving scores at T2, than T2 subjects who completed treatment (p = .03). The results show positive effects of current inpatient treatment programs without differences between different concepts. More research is needed to clarify the impact of treatment drop-out. Attention should be paid to a successful transition from residential to outpatient services and to a reduction of study attrition.