Boundary conditions of methamphetamine craving

Immediate and lasting effects of different regulation of craving strategies on cue-induced craving and the late positive potential in smokers

Craving, induced by substance-related cues, contributes to continued substance use and relapse. Therefore, regulation of craving (ROC) is important for treatment success. Distraction involves disengaging from craving-inducing cues; whereas, reappraisal requires engaging with potential risks of substance use. Given this difference in elaboration, we addressed the question whether reappraisal entails lasting advantages over distraction in successful ROC. To elucidate how this is implemented neurally, we examined the late positive potential (LPP) as an electrocortical indicator of motivated attention to cues. N = 62 smokers viewed smoking-related pictures and indicated the degree of craving each picture induced. While viewing the pictures, EEG was recorded, and the participants focused on the long-term negative (LATER) or short-term positive (NOW) consequences of smoking or performed an arithmetic task to distract themselves from processing the pictures (DISTRACT). After a break, all pictures were presented again without regulation instruction (re-exposure). Results revealed that LATER and DISTRACT achieved similar degrees of immediate ROC success, but only LATER had a sustained effect during re-exposure. In contrast, LPP amplitudes were more prominently reduced during DISTRACT than LATER, and there was no difference in LPP amplitudes during re-exposure. These findings imply that it may be beneficial to engage with the risks of drug use (reappraisal) rather than avoiding triggers of craving (distraction). However, these effects do not seem to be mediated by lasting changes in cue-related motivated attention (LPP).

Methamphetamine dependence in Australia-why is 'ice' (crystal meth) so addictive?

Australia has one of the highest rates in the world of the use of the crystalline form of methamphetamine, a highly addictive stimulant that is often associated with a chronic, relapsing dependency. Methamphetamine use is associated with both acquisitive and violent offending, which cause substantial personal and societal costs. Whilst the short-term euphoria and stimulation provide a positive reinforcement to methamphetamine use, the aversive states of withdrawing from methamphetamine and the associated craving, which may last up to five weeks into abstinence, underlie the negative reinforcement to continued methamphetamine use. Although many methamphetamine-dependent users experience high levels of psychological distress, it is likely that less than half engage with treatment or support services, and current intervention and treatment programmes have high discontinuation rates. Stigma and discrimination, even from paramedics and health clinicians, are prominent barriers to methamphetamine-dependent users accessing treatment in Australia.

Multiple comparison of different noninvasive brain stimulation and pharmacologic interventions in patients with methamphetamine use disorders: A network meta-analysis of randomized controlled trials

AIM

In recent decades, the prevalence of amphetamine and methamphetamine use disorders has at least doubled in some regions/countries, with accompanying high risks of drug overdose-associated mortality. Noninvasive brain stimulation (NIBS) methods may be effective treatments. However, the comparative efficacy of the NIBS protocol for amphetamine/methamphetamine use disorder (AUD/MUD) remains unknown to date. The aim of this network meta-analysis (NMA) was to compare the efficacy and acceptability of various NIBS methods/protocols for AUD/MUD management.

METHODS

A frequentist model-based NMA was conducted. We included randomized controlled trials (RCTs) that investigated the efficacy of NIBS and guideline-recommended pharmacologic treatments to reduce craving severity in patients with either AUD or MUD.

RESULTS

Twenty-two RCTs including 1888 participants met the eligibility criteria. Compared with the sham/placebo group (study = 19, subjects = 891), a combination of intermittent theta burst stimulation over the left dorsolateral prefrontal cortex (DLPFC) and continuous TBS over the left ventromedial prefrontal cortex (study = 1, subjects = 19) was associated with the largest decreases in craving severity [standardized mean difference (SMD) = -1.50; 95% confidence intervals (95%CIs) = -2.70 to -0.31]. High-frequency repetitive transcranial magnetic stimulation over the left DLPFC was associated with the largest improvements in depression and quality of sleep (study = 3, subjects = 86) (SMD = -2.48; 95%CIs = -3.25 to -1.71 and SMD = -2.43; 95%CIs = -3.38 to -1.48, respectively). The drop-out rate of most investigated treatments did not significantly differ between groups.

CONCLUSION

The combined TBS protocol over the prefrontal cortex was associated with the greatest improvement in craving severity. Since few studies were available for inclusion, additional large-scale randomized controlled trials are warranted.

Brief training in regulation of craving reduces cigarette smoking

INTRODUCTION

Craving is an important contributing factor in cigarette smoking and has been added as a diagnostic criterion for addiction in the DSM-5. Cognitive-behavioral therapy and other treatments that incorporate craving regulation strategies reduce smoking and the likelihood of relapse. Although this finding suggests that the regulation of craving is an important mechanism underlying smoking cessation, whether targeted interventions that train smokers to regulate craving can directly impact real-world smoking behaviors is unclear.

METHOD

Across two pilot studies (N = 33; N = 60), we tested whether a brief, computer-delivered training session in the cognitive regulation of craving altered subsequent smoking behaviors in daily life. The study first randomly assigned participants to either a no training (control) group, or one of two Regulation of Craving Training (ROC-T) conditions. Next, all participants came into the lab and those assigned to ROC-T conditions were trained to implement a cognitive strategy to regulate their craving, by either focusing on the negative consequences of smoking, or by distracting themselves. Then, these participants underwent ROC-T during which they practiced using the strategy to regulate their craving during cue exposure. The study subsequently assessed participants' smoking via daily diaries for 3-6 days, and via self-report up to 1-month follow-up.

RESULTS

Across both studies, ROC-T conditions were associated with significant reductions in average cigarettes smoked per day, with effects persisting through follow-up.

CONCLUSION

These results confirm that the regulation of craving is an important mechanism of smoking cessation, and can be targeted via easily administered training procedures, such as ROC-T.

Assessing methamphetamine-related cue reactivity in people with methamphetamine use disorder relative to controls

Methamphetamine use disorder involves methamphetamine-related cues invoking intense craving leading to relapse. Such cue reactivity is thought to arise from Pavlovian conditioning that occurs during the drug-taking experience. Cue reactivity then should be selective to methamphetamine cues (and not other cues), and not observed in people who have never experienced methamphetamine. However, these premises have never been tested and reported using objective measures such as skin conductance response (SCR). The primary aim of this study was to test these premises using a cue reactivity paradigm we developed using control cues. The secondary aim was to explore the relationship between cue reactivity, drug use characteristics, and cognition. Thirty people with a current diagnosis of methamphetamine use disorder and 30 matched controls with no history of substance use disorder were recruited. We observed higher overall subjective reactivity (F = 62.810; p < 0.001) and cue-selective physiological reactivity (F = 5.160; p = 0.026) in people with methamphetamine use disorder but not in controls. Co-morbid sedative use was associated with higher subjective craving (r = 0.521; p = 0.003). People who use methamphetamine intravenously had higher cue-selective SCR than smokers (t = 3.750; p < 0.001). Low inhibitory control measured by the Stroop task was associated with increased craving across the cue paradigm (r = -0.494; p = 0.006). Overall, these results support that cue reactivity in people with methamphetamine use disorder is due to Pavlovian conditioning. Its association with drug use and cognition highlights cue reactivity paradigm's utility in understanding methamphetamine use disorder to develop new treatments targeting cue-induced craving.

The role of CYP2D in rat brain in methamphetamine-induced striatal dopamine and serotonin release and behavioral sensitization

RATIONALE

Cytochrome P450 2D (CYP2D) enzymes metabolize many addictive drugs, including methamphetamine. Variable CYP2D metabolism in the brain may alter CNS drug/metabolite concentrations, consequently affecting addiction liability and neuropsychiatric outcomes; components of these can be modeled by behavioral sensitization in rats.

METHODS

To investigate the role of CYP2D in the brain in methamphetamine-induced behavioral sensitization, rats were pretreated centrally with a CYP2D irreversible inhibitor (or vehicle) 20 h prior to each of 7 daily methamphetamine (0.5 mg/kg subcutaneous) injections. In vivo brain microdialysis was used to assess brain drug and metabolite concentrations, and neurotransmitter release.

RESULTS

CYP2D inhibitor (versus vehicle) pretreatment enhanced methamphetamine-induced stereotypy response sensitization. CYP2D inhibitor pretreatment increased brain methamphetamine concentrations and decreased the brain p-hydroxylation metabolic ratio. With microdialysis conducted on days 1 and 7, CYP2D inhibitor pretreatment exacerbated stereotypy sensitization and enhanced dopamine and serotonin release in the dorsal striatum. Day 1 brain methamphetamine and amphetamine concentrations correlated with dopamine and serotonin release, which in turn correlated with the stereotypy response slope across sessions (i.e., day 1 through day 7), used as a measure of sensitization.

CONCLUSIONS

CYP2D-mediated methamphetamine metabolism in the brain is sufficient to alter behavioral sensitization, brain drug concentrations, and striatal dopamine and serotonin release. Moreover, day 1 methamphetamine-induced neurotransmitter release may be an important predictor of subsequent behavioral sensitization. This suggests the novel contribution of CYP2D in the brain to methamphetamine-induced behavioral sensitization and suggests that the wide variation in human brain CYP2D6 may contribute to differential methamphetamine responses and chronic effects.

A Scoping Review on Cue Reactivity in Methamphetamine Use Disorder

The experience of craving via exposure to drug-related cues often leads to relapse in drug users. This study consolidated existing empirical evidences of cue reactivity to methamphetamine to provide an overview of current literature and to inform the directions for future research. The best practice methodological framework for conducting scoping review by Arkey and O'Malley was adopted. Studies that have used a cue paradigm or reported on cue reactivity in persons with a history of methamphetamine use were included. Databases such as Medline, EMBASE, PsycINFO and CINAHL were searched using key terms, in addition to citation check and hand search. The search resulted in a total of 32 original research articles published between 2006 to 2020. Three main themes with regard to cue reactivity were identified and synthesized: (1) effects of cue exposure, (2) individual factors associated with cue reactivity, and (3) strategies that modulate craving or reactivity to cues. Exposure to methamphetamine-associated cues elicits significant craving and other autonomic reactivity. Evidence suggests that drug cue reactivity is strongly associated with indices of drug use and other individual-specific factors. Future studies should focus on high quality studies to support evidence-based interventions for reducing cue reactivity and to examine cue reactivity as an outcome measure.

Regulation of Craving and Negative Emotion in Alcohol Use Disorder

BACKGROUND

Alcohol use disorder (AUD) is a chronic, relapsing condition with poor treatment outcomes. Both alcohol craving and negative affect increase alcohol drinking, and-in healthy adults-can be attenuated using cognitive strategies, which rely on the prefrontal cortex (PFC). However, AUD is associated with cognitive impairments and PFC disruptions. Thus, we tested whether individuals with AUD can successfully recruit the PFC to effectively regulate craving and negative emotions, whether neural mechanisms are shared between the two types of regulation, and whether individual differences influence regulation success.

METHODS

During functional magnetic resonance imaging, participants with AUD completed the regulation of craving task (n = 17) that compares a cue-induced craving condition with an instructed regulation condition. They also completed the emotion regulation task (n = 15) that compares a negative affect condition with an instructed regulation condition. Regulation strategies were drawn from cognitive behavioral therapy treatments for AUD. Self-reported craving and negative affect were collected on each trial.

RESULTS

Individuals with AUD effectively regulated their craving and negative affect when instructed to do so using cognitive behavioral therapy-based strategies. Regulation was associated with recruitment of both common and distinct PFC regions across tasks, as well as with reduced activity in regions associated with craving and negative affect (e.g., ventral striatum, amygdala). Effective regulation of craving was associated with negative alcohol expectancies.

CONCLUSIONS

Both common and distinct regulatory systems underlie regulation of craving and negative emotions in AUD, with notable individual differences. This has important implications for AUD treatment.

Training in cognitive strategies reduces eating and improves food choice

Obesity rates continue to rise alarmingly, with dire health implications. One contributing factor is that individuals frequently forgo healthy foods in favor of inexpensive, high-calorie, unhealthy foods. One important mechanism underlying these choices is food craving: Craving increases with exposure to unhealthy foods (and food cues, such as advertisements) and prospectively predicts eating and weight. Prior work has shown that cognitive regulation strategies that emphasize the negative consequences of unhealthy foods reduce craving. In Studies 1 and 2, we show that cognitive strategies also increase craving for healthy foods by emphasizing their positive benefits, and change food valuation (willingness to pay) for both healthy and unhealthy foods. In Studies 3 and 4, we demonstrate that brief training in cognitive strategies ("Regulation of Craving Training"; ROC-T) increases subsequent healthy (vs. unhealthy) food choices. This was striking because this change in food choices generalized to nontrained items. Importantly, in Study 5, we show that brief training in cognitive strategies also reduces food consumption by 93-121 calories. Consumed calories correlated with changes in food choice. Finally, in Study 6, we show that the training component of ROC-T is necessary, above and beyond any effect of framing. Across all studies (NTOTAL = 1,528), we find that cognitive strategies substantially change craving and food valuation, and that training in cognitive strategies improves food choices by 5.4-11.2% and reduces unhealthy eating, including in obese individuals. Thus, these findings have important theoretical, public health, and clinical implications for obesity prevention and treatment.

Factors related to methamphetamine relapse risk among clients in the substance rehabilitation center of National Narcotics Board in West Java, Indonesia

Purpose

This purpose of this paper is to describe methamphetamine relapse risk, examine the relationship between factors in the dynamic model of relapse and methamphetamine relapse risk.

Design/methodology/approach

A total of 165 clients from the Substance Rehabilitation Center of National Narcotics Board in West Java, Indonesia were recruited. The research instruments included a demographic characteristic questionnaire and eight different tests: Drug Taking Confidence Questionnaire; Stimulant Effect Expectancy Questionnaire; Stage of Change Readiness and Treatment Eagerness Scale version 8.0 for Drug; Coping Strategies Inventory Short Form; Positive Affect and Negative Affect Schedule; Desire for Speed Questionnaire; Social Support Questionnaire; and the Stimulant Relapse Risk Scale. Descriptive statistics were used to analyze the data. Pearson’s product moment correlation was used to test the relationship among variables.

Findings

Clients (63 percent) were at a moderate level of methamphetamine relapse risk (mean=56.33, SD=10.54). Outcome expectancy, positive emotional state, negative emotional state and craving were positive and had a significant correlation with relapse risk (r=0.261, r=0.380, r=0.370, r=0.509, p<0.01, respectively). Self-efficacy was negative and had a significant correlation with relapse risk (r=−0.316, p<0.01). Motivation, coping and social support had no correlation with relapse risk.

Originality/value

Two-thirds of the clients in a rehabilitation center have a tendency to relapse following treatment. Nursing intervention for early detection of methamphetamine relapse risk during treatment by using standardized instruments should be implemented.

Molecular, Behavioral, and Physiological Consequences of Methamphetamine Neurotoxicity: Implications for Treatment

Understanding the relationship between the molecular mechanisms underlying neurotoxicity of high-dose methamphetamine (METH) and related clinical manifestations is imperative for providing more effective treatments for human METH users. This article provides an overview of clinical manifestations of METH neurotoxicity to the central nervous system and neurobiology underlying the consequences of administration of neurotoxic METH doses, and discusses implications of METH neurotoxicity for treatment of human abusers of the drug.

Functional neural changes following behavioral therapies and disulfiram for cocaine dependence

A growing literature exists on neural correlates of treatment outcome. However, different types-or components of-treatment have distinct theorized mechanisms of action. And it is not yet known how changes in neural activity across treatment relate to engagement in different treatment components. Participants with cocaine use disorders in a randomized clinical trial received cognitive-behavioral therapy (CBT) plus, in a 2 × 2 design, contingency management (CM) or no CM, and disulfiram or placebo. Participants performed a functional MRI Stroop task, a measure of cognitive control, at the beginning of and after the 12-week treatment. Analyses assessed changes in Stroop-related neural activity within the sample overall and assessed how changes in Stroop-related activity correlated with measures of treatment process specific to each form of treatment (i.e., participation in CBT sessions, receipt of CM prizes, administration of disulfiram pills). Within the sample overall, compared with beginning of treatment, posttreatment Stroop-related neural activity was diminished in the hippocampus, thalamus, cingulate, precentral, post- and precentral gyrus, and precuneus and culmen regions (pFWE < .05). In separate whole-brain correlation analyses, greater reductions in Stroop-related activity were associated with more treatment engagement-"CBT sessions" with the precentral gyrus, inferior parietal lobule, and middle and medial frontal gyrus; "CM prizes" with the postcentral frontal gyrus. Disulfiram "medication days" were not associated with changes in Stroop-related activity. Findings suggest that key process indicators of CBT and CM may be associated with functional changes in cognitive-control-related neurocircuitry. (PsycINFO Database Record

Psychosocial interventions in stimulant use disorders: a focus on women

PURPOSE OF REVIEW

Stimulant use disorders are significant contributors to the global burden of disease, with a growing impact on women. Psychosocial interventions are the gold standard for treating this condition, but several barriers may prevent women from accessing appropriate treatment. Therefore, we systematically reviewed the most recent findings about psychosocial interventions for stimulant use disorders, focussing on results relevant to women.

RECENT FINDINGS

Twenty-two eligible studies were identified. Psychosocial interventions in stimulant use disorders were examined in 17 recent studies, but no analyses for sex-related differences were performed. These aspects were investigated in further five studies, either through secondary analyses on the female subgroup or specifically examining a female-only sample. Contingency management, either alone or in combination with other interventions, provided the most positive results on several outcome measures. Only one pilot study showed good potential for an alternative approach of systemic family therapy, warranting further research in this direction.

SUMMARY

Research in stimulant use disorders shows an increasing interest in exploring interventions capable of addressing sex-specific issues. Combined therapy including contingency management and other treatments appears the most promising option, but larger secondary studies are needed to rank the efficacy of different psychosocial interventions while considering their feasibility and acceptability in specific subpopulations, including women.

Food cue reactivity and craving predict eating and weight gain: a meta-analytic review

According to learning-based models of behavior, food cue reactivity and craving are conditioned responses that lead to increased eating and subsequent weight gain. However, evidence supporting this relationship has been mixed. We conducted a quantitative meta-analysis to assess the predictive effects of food cue reactivity and craving on eating and weight-related outcomes. Across 69 reported statistics from 45 published reports representing 3,292 participants, we found an overall medium effect of food cue reactivity and craving on outcomes (r = 0.33, p < 0.001; approximately 11% of variance), suggesting that cue exposure and the experience of craving significantly influence and contribute to eating behavior and weight gain. Follow-up tests revealed a medium effect size for the effect of both tonic and cue-induced craving on eating behavior (r = 0.33). We did not find significant differences in effect sizes based on body mass index, age, or dietary restraint. However, we did find that visual food cues (e.g. pictures and videos) were associated with a similar effect size to real food exposure and a stronger effect size than olfactory cues. Overall, the present findings suggest that food cue reactivity, cue-induced craving and tonic craving systematically and prospectively predict food-related outcomes. These results have theoretical, methodological, public health and clinical implications.

Neuropsychological Consequences of Chronic Drug Use: Relevance to Treatment Approaches

Heavy use of drugs impacts of the daily activities of individuals in these activities. Several groups of investigators have indeed documented changes in cognitive performance by individuals who have a long history of chronic drug use. In the case of marijuana, a wealth of information suggests that heavy long-term use of the drug may have neurobehavioral consequences in some individuals. In humans, heavy cocaine use is accompanied by neuropathological changes that might serve as substrates for cognitive dysfunctions. Similarly, methamphetamine users suffer from cognitive abnormalities that may be consequent to alterations in structures and functions. Here, we detail the evidence for these neuropsychological consequences. The review suggests that improving the care of our patients will necessarily depend on the better characterization of drug-induced cognitive phenotypes because they might inform the development of better pharmacological and behavioral interventions, with the goal of improving cognitive functions in these subsets of drug users.