PPAR-gamma agonist pioglitazone modifies craving intensity and brain white matter integrity in patients with primary cocaine use disorder: a double-blind randomized controlled pilot trial

The role of Iowa gambling task performance in response to citalopram treatment for cocaine use disorder

Background: Cocaine use disorder (CUD) is associated with executive functioning impairments linked to serotonergic function. Previous studies reported efficacy with the selective serotonin reuptake inhibitor citalopram in reducing cocaine use.Objectives: The current study explored moderation and mediation of citalopram effects on cocaine use by performance across executive function domains.Methods: We conducted a secondary analysis of a double-blind, placebo-controlled, randomized Bayesian adaptive trial investigating citalopram efficacy in CUD treatment-seeking adults. At baseline and mid-treatment, participants completed assessments of decision-making (Iowa Gambling Task; IGT), attention, response inhibition, and cognitive flexibility. Outcomes were longest duration of abstinence (LDA; count of consecutive cocaine-negative urine tests) and Treatment Effectiveness Score (TES; count of cocaine-negative urine tests from study midpoint to endpoint). Bayesian models estimated independent moderation and mediation effects of cognitive ability on the association between treatment (citalopram 40 mg vs. placebo) and LDA/TES.Results: Of the four assessments, only the IGT demonstrated concurrent moderation and mediation in the sample (N = 80; 82% males). Treatment effects on LDA (IRR = 1.02) and TES (IRR = 1.03) were strongest in participants with higher baseline IGT scores, which indicate less risky decision-making (posterior probabilities >93%). Models supported a positive indirect effect of treatment on TES (IRR = 1.12, posterior probability = 81.6%), with 52.3% of the total effect mediated by changes in IGT scores from baseline to mid-treatment.Conclusion: We found evidence for IGT as a moderator and mediator of citalopram's effects on cocaine use. Decision-making ability may play a role in predicting who responds to citalopram and how.

Cannabinoid-based Pharmacology for the Management of Substance Use Disorders

In the last two decades, the endocannabinoid system has emerged as a crucial modulator of motivation and emotional processing. Due to its widespread neuroanatomical distribution and characteristic retrograde signaling nature, cannabinoid type I receptors and their endogenous ligands finely orchestrate somatic and axon terminal activity of dopamine neurons. Owing to these unique features, this signaling system is a promising pharmacological target to ameliorate dopamine-mediated drug-seeking behaviors while circumventing the adverse side effects of, for instance, dopaminergic antagonists. Despite considerable preclinical efforts, an agreement on the efficacy of endocannabinoid-targeting compounds for treating drug substance use disorders in humans has not been reached. In the following chapter, we will summarize preclinical and clinical evidence addressing the therapeutic potential of cannabinoids and endocannabinoid-targeting compounds in substance use disorders. To bridge the gap between animal and clinical research, we capitalize on studies evaluating the impact of endocannabinoid-targeting compounds in relevant settings, such as the management of drug relapse. Finally, we discuss the therapeutic potential of novel cannabinoid compounds that hold promise for treating substance use disorders.

Ketamine impairs the performance of male mice in novel recognition object test and reduces the immunoreactivity of GAD67 in the hippocampus: Role of pioglitazone

Schizophrenia is a mental disorder characterized by positive, negative, and cognitive symptoms which is treated with antipsychotics. However, these drugs present several side effects and, some schizophrenia symptoms, like cognitive, are difficult to treat. The peroxisome proliferator-activated receptors-gamma (PPAR-γ) are expressed in dopaminergic neurons of the midbrain participating in the modulation of dopamine-mediated behavior . We investigated the effects of pioglitazone, an agonist of PPAR-γ, on the behavioral alterations induced by ketamine and, whether alterations in monoamine oxidase (MAO) activity, glutamic acid decarboxylase (GAD67), PPAR-γ or tyrosine hydroxylase (TH) immunoreactivity in brain tissues are involved in these effects. Male mice received ketamine (30 mg/kg), intraperitoneally, for 14 consecutive days, and pioglitazone (3 or 9 mg/kg), by gavage (day 8 up to day 14). Ketamine decreased nail-biting increasing the time exploring the center of the open field on day 8 and the number of rearing evaluated 30 min after its administration on day 14. Furthermore, ketamine decreased the percentage of investigation in the NOR test and the immunoreactivity of GAD67 in the hippocampus. No significant changes were found in other behavioral and biochemical tests. Pioglitazone attenuated the effects of ketamine on rearing and GAD67 immunoreactivity in the hippocampus, recovering the ketamine effects on NOR test. At a dose of 9 mg/kg, pioglitazone alone reduced the immunoreactivity of GAD67 in the hippocampus. Pioglitazone at both doses recovered the cognitive symptoms induced by ketamine an effect that seems to involve the modulation of GAD67 immunoreactivity in the hippocampus. In conclusion, pioglitazone improved the effects of ketamine on the NOR test which was, at least in part, associated with the modulation of GAD67 immunoreactivity in the hippocampus suggesting its beneficial role in cognitive symptoms.

Emerging medications and pharmacological treatment approaches for substance use disorders

Medications to treat substance use disorders remain suboptimal or, in the case of stimulants and cannabis, non-existent. Many factors have contributed to this paucity, including the biological complexity of addiction, regulatory challenges, and a historical lack of enthusiasm among pharmaceutical companies to commit resources to this disease space. Despite these headwinds, the recent opioid crisis has highlighted the devastating consequences of SUDs for both individuals and society, stimulating urgent efforts to identify novel treatment approaches. In addition, several neurobiological systems have been recently implicated in unique aspects of drug reward, opening the door to candidate medications with novel mechanisms of action. Here, we provide an overview of efforts to target several of these new systems, with a focus on those that are the subject of ongoing clinical trials as well as being areas of interest among the authors' research groups (MHJ, MTB, NAE). Specifically, we discuss new classes of medications targeting the serotonin 2 A receptor (i.e., psychedelics), glucagon-like peptide 1 receptor, cannabidiol, dynorphin/kappa opioid receptor, orexin/hypocretin, and oxytocin receptor systems, as well as emergent approaches for modulating the more canonical dopaminergic system via agonist therapies for stimulant use disorders. Collectively, innovations in this space give reason for optimism for an improved therapeutic landscape for substance use disorders in the near future.

New insights into the involvement of serotonin and BDNF-TrkB signalling in cannabidiol's antidepressant effect

Cannabidiol (CBD) is a phytocannabinoid devoid of psychostimulant properties and is currently under investigation as a potential antidepressant drug. However, the mechanisms underlying CBD's antidepressant effects are not yet well understood. CBD targets include a variety of receptors, enzymes, and transporters, with different binding-affinities. Neurochemical and pharmacological evidence indicates that both serotonin and BDNF-TrkB signalling in the prefrontal cortex are necessary for the antidepressant effects induced by CBD in animal models. Herein, we reviewed the current literature to dissect if these are independent mechanisms or if CBD-induced modulation of the serotonergic neurotransmission could mediate its neuroplastic effects through subsequent regulation of BDNF-TrkB signalling, thus culminating in rapid neuroplastic changes. It is hypothesized that: a) CBD interaction with serotonin receptors on neurons of the dorsal raphe nuclei and the resulting disinhibition of serotonergic neurons would promote rapid serotonin release in the PFC and hence its neuroplastic and antidepressant effects; b) CBD facilitates BDNF-TRKB signalling, especially in the PFC, which rapidly triggers neurochemical and neuroplastic effects. These hypotheses are discussed with perspectives for new drug development and clinical applications.

Substance Addiction Rehabilitation Drugs

The relapse rate of substance abusers is high, and addiction rehabilitation adjunct drugs need to be developed urgently. There have been numerous reports on blocking the formation of substance addiction, but studies on drugs that can alleviate withdrawal symptoms are very limited. Both the dopamine transporter (DAT) hypothesis and D3 dopamine receptor (D3R) hypothesis are proposed. DAT activators reduce the extracellular dopamine level, and D3R antagonists reduce the neuron's sensitivity to dopamine, both of which may exacerbate the withdrawal symptoms subsequently. The D3R partial agonist SK608 has biased signaling properties via the G-protein-dependent pathway but did not induce D3R desensitization and, thus, may be a promising drug for the withdrawal symptoms. Drugs for serotoninergic neurons or GABAergic neurons and anti-inflammatory drugs may have auxiliary effects to addiction treatments. Drugs that promote structural synaptic plasticity are also discussed.

Promising immunomodulators for management of substance and alcohol use disorders

INTRODUCTION

The neuroimmune system has emerged as a novel target for the treatment of substance use disorders (SUDs), with immunomodulation producing encouraging therapeutic benefits in both preclinical and clinical settings.

AREAS COVERED

In this review, we describe the mechanism of action and immune response to methamphetamine, opioids, cocaine, and alcohol. We then discuss off-label use of immunomodulators as adjunctive therapeutics in the treatment of neuropsychiatric disorders, demonstrating their potential efficacy in affective and behavioral disorders. We then discuss in detail the mechanism of action and recent findings regarding the use of ibudilast, minocycline, probenecid, dexmedetomidine, pioglitazone, and cannabidiol to treat (SUDs). These immunomodulators are currently being investigated in clinical trials described herein, specifically for their potential to decrease substance use, withdrawal severity, central and peripheral inflammation, comorbid neuropsychiatric disorder symptomology, as well as their ability to improve cognitive outcomes.

EXPERT OPINION

We argue that although mixed, findings from recent preclinical and clinical studies underscore the potential benefit of immunomodulation in the treatment of the behavioral, cognitive, and inflammatory processes that underlie compulsive substance use.

Neuroimmune modulators as novel pharmacotherapies for substance use disorders

One promising avenue of research is the use of neuroimmune modulators to treat substance use disorders (SUDs). Neuroimmune modulators target the interactions between the nervous system and immune system, which have been found to play a crucial role in the development and maintenance of SUDs. Multiple classes of substances produce alterations to neuroimmune signaling and peripheral immune function, including alcohol, opioids, and psychostimulants Preclinical studies have shown that neuroimmune modulators can reduce drug-seeking behavior and prevent relapse in animal models of SUDs. Additionally, early-phase clinical trials have demonstrated the safety and feasibility of using neuroimmune modulators as a treatment for SUDs in humans. These therapeutics can be used as stand-alone treatments or as adjunctive. This review summarizes the current state of the field and provides future directions with a specific focus on personalized medicine.

An opioid-minimizing multimodal pain regimen reduces opioid exposure and pain in trauma-injured patients at high risk for opioid misuse: Secondary analysis from the mast trial

BACKGROUND

Screening to identify patients at risk for opioid misuse after trauma is recommended but not commonly used to guide perioperative opioid management interventions. The Multimodal Analgesic Strategies for Trauma trial demonstrated that an opioid-minimizing multimodal pain regimen reduced opioid exposure in a heterogeneous trauma patient population. Here, we assess the efficacy of the Multimodal Analgesic Strategies for Trauma multimodal pain regimen in a critical patient subgroup who screened at high risk for opioid misuse.

METHODS

The Multimodal Analgesic Strategies for Trauma trial compared an opioid-minimizing multimodal pain regimen (oral acetaminophen, naproxen, gabapentin, lidocaine patch, as-needed opioid) against an original multimodal pain regimen (intravenous followed by oral acetaminophen, 48-hour celecoxib and pregabalin, followed by naproxen and gabapentin, scheduled tramadol, as-needed opioid), in a randomized trial conducted from April 2018 to March 2019. A total of 631 enrolled patients were classified either as low- or high-risk via the Opioid Risk Tool. Bayesian analyses evaluated the moderating influence of Opioid Risk Tool risk (high/low) on the effect of Multimodal Analgesic Strategies for Trauma multimodal pain regimen (versus original) on opioid exposure (morphine milligram equivalents/day), opioids prescribed at discharge, and pain scores.

RESULTS

Multimodal Analgesic Strategies for Trauma multimodal pain regimen effectively reduced morphine milligram equivalents/day in low- and high-Opioid Risk Tool risk groups. Moderation was observed for opioids at discharge and pain scores; Multimodal Analgesic Strategies for Trauma multimodal pain regimen was effective in the high-risk group only (opioids at discharge: 63% vs 77%, relative risk = 0.86, 95% Bayesian credible interval [0.66-1.08], posterior probability (relative risk <1) = 90%; pain scores: b = 3.8, 95% Bayesian credible interval [3.2-4.4] vs b = 4.0, 95% Bayesian credible interval [3.4-4.6], posterior probability (b <0) = 87%).

CONCLUSION

This study is the first to show the moderating influence of opioid misuse risk on the effectiveness of an opioid-minimizing multimodal pain regimen. The Opioid Risk Tool was useful in identifying high-risk patients for whom the Multimodal Analgesic Strategies for Trauma multimodal pain regimen is recommended for perioperative pain management.

Substance use among older adults: a review of the literature

OBJECTIVES

To explore studies that have examined the effectiveness of possible interventions to reduce the substance use among older adults.

METHODS

From the search, 295 abstracts were identified and 200 were excluded. Ninety-five remaining articles were reviewed, and 90 were excluded after full text review. Nine articles were included after reviewing bibliographic references on the topic. A total of 14 articles, which all met the inclusion criteria, were considered in the review.

RESULTS

All 14 studies found that pharmacological and non-pharmacological interventions can reduce substance use (alcohol, cocaine, nicotine and benzodiazepines) among older adults (mean age 45 years or older).

CONCLUSIONS

There are promising possibly pharmacological and non-pharmacological interventions that can be used to reduce substance use among older adults. In addition, other studies are needed to expand the therapeutic arsenal in this population.

Assessing cocaine motivational value: Comparison of brain reactivity bias toward cocaine cues and cocaine demand

The behavioral economic measure drug demand and the neural measure late positive potential (LPP) are two measures of motivational value that have been associated with drug relapse risk and treatment outcomes. Despite having overlapping themes, no studies have directly compared drug demand and LPP. Participants (N = 59) included treatment-seeking individuals with cocaine use disorder that had completed both a baseline cocaine demand task and an electroencephalogram (EEG) picture-viewing task of drug-related and pleasant picture cues. Associations between the LPP difference score amplitude (drug-pleasant) and five demand indices (Q₀, essential value [EV], Omax, Pmax, and breakpoint [BP]) were evaluated via Bayesian generalized linear modeling. Positive associations (posterior probabilities ≥ 75%) were found between LPP amplitude and four demand indices (Q₀, EV, Omax, BP). These results suggest that individuals who attach greater relevance to cocaine cues also exhibit greater valuation of cocaine reward. Implications for incorporating methodology from behavioral science and brain imaging are discussed. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Cannabidiol goes nuclear: The role of PPARγ

BACKGROUND

Cannabidiol (CBD) is one of the main phytocannabinoids found in Cannabis sativa. In contrast to Δ9-tetrahydrocannabinol, it has a low affinity for cannabinoid receptors CB1 and CB2, thereby it does not induce significant psychoactive effects. However, CBD may interact with other receptors, including peroxisome proliferator-activated receptor gamma (PPARγ). CBD is a PPARγ agonist and changes its expression. There is considerable evidence that CBD's effects are mediated by its interaction with PPARγ. So, we reviewed studies related to the interaction of CBD and PPARγ.

METHODS

In this comprehensive literature review, the term 'cannabidiol' was used in combination with the following keywords including 'PPARγ', 'Alzheimer's disease', 'Parkinson's disease', 'seizure', 'multiple sclerosis', 'immune system', 'cardiovascular system', 'cancer', and 'adipogenesis'. PubMed, Web of Science, and Google Scholar were searched until December 20, 2022. A total of 78 articles were used for the reviewing process.

RESULTS

CBD, via activation of PPARγ, promotes significant pharmacological effects. The present review shows that the effects of CBD on Alzheimer's disease and memory, Parkinson's disease and movement disorders, multiple sclerosis, anxiety and depression, cardiovascular system, immune system, cancer, and adipogenesis are mediated, at least in part, via PPARγ.

CONCLUSION

CBD not only activates PPARγ but also affects its expression in the body. It was suggested that the late effects of CBD are mediated via PPARγ activation. We suggested that CBD's chemical structure is a good backbone for developing new dual agonists. Combining it with other chemicals enhances their biological effectiveness while reducing their dosage. The present study indicated that PPARγ is a key target for CBD, and its activation by CBD should be considered in all future studies.

Novel role of AMPK in cocaine reinforcement via regulating CRTC1

Repeated cocaine exposure causes compensatory neuroadaptations in neurons in the nucleus accumbens (NAc), a region that mediates reinforcing effects of drugs. Previous studies suggested a role for adenosine monophosphate-activated protein kinase (AMPK), a cellular energy sensor, in modulating neuronal morphology and membrane excitability. However, the potential involvement of AMPK in cocaine use disorder is still unclear. The present study employed a cocaine self-administration model in rats to investigate the effect of AMPK and its target cyclic adenosine monophosphate response element binding protein-regulated transcriptional co-activator 1 (CRTC1) on cocaine reinforcement and the motivation for cocaine. We found that intravenous cocaine self-administration significantly decreased AMPK activity in the NAc shell (NAcsh), which persisted for at least 7 days of withdrawal. Cocaine reinforcement, reflected by self-administration behavior, was significantly prevented or enhanced by augmenting or suppressing AMPK activity pharmacologically and genetically, respectively. No difference in sucrose self-administration behavior was found after the same manipulations. The inhibition of AMPK activity in the NAcsh also increased the motivation for cocaine in progressive-ratio schedules of reinforcement, whereas the activation of AMPK had no effect. The knockdown of CRTC1 in the NAcsh significantly impaired cocaine reinforcement, which was rescued by pharmacologically increasing AMPK activity. Altogether, these results indicate that AMPK in the NAcsh is critical for cocaine reinforcement, possibly via the regulation of CRTC1 signaling. These findings may help reveal potential therapeutic targets and have important implications for the treatment of cocaine use disorder and relapse.

Pharmacological Treatments for Cocaine Craving: What Is the Way Forward? A Systematic Review

BACKGROUND

cocaine craving is a core feature of cocaine use disorder and remains a critical challenge for abstinence and relapse prevention. This review summarizes the anti-craving efficacy of pharmacotherapies tested for cocaine use disorder, in the context of randomized-controlled clinical trials.

OBJECTIVES

we assessed the databases of the U.S. National Library of Medicine, Google Scholar, and PsycINFO, without date restrictions up to August 2022, to identify relevant studies.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS, AND INTERVENTIONS

we included double-blinded randomized-controlled trials investigating pharmacotherapies for cocaine craving and/or cocaine use disorder whose outcomes included cocaine craving.

STUDY APPRAISAL AND SYNTHESIS METHODS

Two authors screened studies' titles and abstracts for inclusion, and both read all the included studies. We systematically gathered information on the following aspects of each study: title; author(s); year of publication; sample size; mean age; sample characteristics; study set-ting; whether participants were treatment-seeking; study design; craving measures; study interventions; drop-out rates; and other relevant outcomes.

RESULTS

Overall, we appraised 130 clinical trials, including 8137 participants. We further considered the drugs from the studies that scored equal to or greater than six points in the quality assessment. There was a correlation between craving and cocaine use outcomes (self-reports, timeline follow-back or urinary benzoylecgonine) in the vast majority of studies. In the short-term treatment, acute phenylalanine-tyrosine depletion, clonidine, fenfluramine, meta-chlorophenylpiperazine (m-CPP) and mecamylamine presented promising effects. In the long term, amphetamine, biperiden, carbamazepine, lisdexamfetamine, lorcaserin, methamphetamine, mirtazapine, pioglitazone, progesterone, guanfacine, levodopa, nefazodone presented promising anti-craving effects. Unfortunately, the highly tested medications were not successful in most of the trials, as follows: propranolol in the short term; amantadine, aripiprazole, bromocriptine, citicoline, ketamine, modafinil, olanzapine, topiramate in the long term. The remaining 52 medications had no positive anti-craving outcomes.

LIMITATIONS

Our review was limited by high heterogeneity of craving assessments across the studies and by a great range of pharmacotherapies. Further, the majority of the studies considered abstinence and retention in treatment as the main outcomes, whereas craving was a secondary outcome and some of the studies evaluated patients with cocaine use disorder with comorbidities such as opioid or alcohol use disorder, schizophrenia, bipolar disorder or attention deficit hyperactivity. Lastly, most of the studies also included non-pharmacological treatments, such as counseling or psychotherapy.

CONCLUSIONS

There is a direct association between craving and cocaine use, underscoring craving as an important treatment target for promoting abstinence among persons with cocaine use disorder. Clonidine, fenfluramine and m-CPP showed to be promising medications for cocaine craving in the short-term treatment, and amphetamine, biperiden, carbamazepine, lisdexamfetamine, lorcaserin, methamphetamine, mirtazapine, pioglitazone, progesterone, guanfacine, levodopa, nefazodone in the long-term treatment.

Facilitating treatment initiation and reproductive care postpartum to prevent substance-exposed pregnancies: A randomized bayesian pilot trial

BACKGROUND

For non-treatment-seeking women who use substances during pregnancy, immediately postpartum may be an optimum time for intervention. Our study tested a novel, brief, hospital-initiated, adaptive motivational interviewing plus acceptance and commitment therapy (MIACT) intervention to facilitate treatment initiation and reproductive planning postpartum among mothers who used substances during pregnancy.

METHODS

Mothers (N = 64) with an infant admitted to a neonatal intensive care unit were enrolled if they or their infant tested positive for an illicit substance at delivery or had a documented positive drug screen during pregnancy. A parallel group, randomized controlled design assigned participants to MIACT or conventional care (CC), with assessments at week 2 and 4 during treatment and follow-up at 2 and 6 months post treatment. Bayesian generalized linear modeling was used to evaluate outcomes as a function of treatment.

RESULTS

Results indicated that during treatment the MIACT group demonstrated an 84% probability of benefit relative to CC with regard to initiating treatment (RR=1.5), however the effect was not seen at follow-up. MIACT was also associated with an increased probability of attending a postpartum obstetrics visit (RR=1.4), and receiving contraception during treatment and at both follow-ups, with posterior probabilities of 96% or higher and relative risks ranging from 1.5 to 5.1 at varying timepoints. Substance use rates for the MIACT versus CC were higher at follow-up.

CONCLUSIONS

Brief, hospital-initiated interventions can assist postpartum mothers who use substances to enter treatment and obtain contraception in order to reduce future substance-exposed pregnancies.

Sustained drug delivery strategies for treatment of common substance use disorders: Promises and challenges

Substance use disorders (SUDs) are a leading cause of death and other ill health effects in the United States and other countries in the world. Several approaches ranging from detoxification, behavioral therapy, and the use of antagonists or drugs with counter effects are currently being applied for its management. Amongst these, drug therapy is the mainstay for some drug abuse incidences, as is in place specifically for opioid abuse or alcohol dependence. The severity of the havocs observed with the SUDs has triggered constant interest in the discovery and development of novel medications as well as suitable or most appropriate methods for the delivery of these agents. The chronic need of such drugs in users warrants the need for their prolonged or sustained systemic availability. Further, the need to improve patient tolerance to medication, limit invasive drug use and overall treatment outcome are pertinent considerations for embracing sustained release designs for medications used in managing SUDs. This review aims to provide an overview on up-to-date advances made with regards to sustained delivery systems for the drugs for treatment of different types of SUDs such as opioid, alcohol, tobacco, cocaine, and cannabis use disorders. The clinical relevance, promises and the limitations of deployed sustained release approaches along with future opportunities are discussed.

Cannabidiol and substance use disorder: Dream or reality

BACKGROUND

Cannabidiol (CBD) is one of the major constituents of Cannabis sativa L. that lacks psychotomimetic and rewarding properties and inhibits the rewarding and reinforcing effects of addictive drugs such as cocaine, methamphetamine (METH), and morphine. Additionally, CBD's safety profile and therapeutic potential are currently evaluated in several medical conditions, including pain, depression, movement disorders, epilepsy, multiple sclerosis, Alzheimer's disease, ischemia, and substance use disorder. There is no effective treatment for substance use disorders such as addiction, and this review aims to describe preclinical and clinical investigations into the effects of CBD in various models of opioid, psychostimulant, cannabis, alcohol, and nicotine abuse. Furthermore, the possible mechanisms underlying the therapeutic potential of CBD on drug abuse disorders are reviewed.

METHODS

The current review considers and summarizes the preclinical and clinical investigations into CBD's effects in various models of drug abuse include opioids, psychostimulants, cannabis, alcohol, and nicotine.

RESULTS

Several preclinical and clinical studies have proposed that CBD may be a reliable agent to inhibit the reinforcing and rewarding impact of drugs.

CONCLUSIONS

While the currently available evidence converges to suggest that CBD could effectively reduce the rewarding and reinforcing effects of addictive drugs, more preclinical and clinical studies are needed before CBD can be added to the therapeutic arsenal for treating addiction.

The Association of Drug-Use Characteristics and Active Coping Styles With Positive Affect in Patients With Heroin-Use Disorder and Methamphetamine-Use Disorder During the COVID-19 Pandemic

Background: Positive affect (PA) is crucial for individuals to cope with the current pandemic and buffer the lingering fears after it, especially for patients with substance-use disorders (SUDs). The current study aimed to explore PA and its related factors during the COVID-19 pandemic in male patients with the heroin-use disorder (HUD) and patients with the methamphetamine-use disorder (MAUD), respectively.

Methods: A total of 325 male patients with SUDs (106 with HUD and 219 with MAUD, all were single-substance users) in a compulsory rehabilitation center underwent semi-structured interviews during the pandemic. The demographic information, drug-use characteristics, active coping styles (ACSs, by Simple Coping Style Questionnaire), and PA (by the Positive and Negative Affect Scale) of participants were collected and recorded.

Results: There were significant differences between the two groups in age, the proportion of full-time workers before the epidemic, duration of drug use, the proportion of patients with long-term withdrawal during the epidemic, cravings, ACS, and PA. Correlation and multiple linear regression analysis showed that duration of drug use, ACS, and stable jobs were significant predictive factors for PA in patients with HUD, while long-term withdrawal, ACS, and stable jobs during the epidemic were significant predictive factors for PA in patients with MAUD.

Conclusions: Our study demonstrated the factors for PA in patients with HUD and MAUD during the pandemic. The results provided a basis for the comprehensive understanding of the PA of patients with SUDs and the development of targeted treatments.

The transdiagnostic role of food craving: An application of substance use models

Food craving is a transdiagnostic process underlying clinically significant disordered eating behaviors and eating disorder diagnoses. However, the lack of literature examining the role of food craving as it relates to the full spectrum of disordered eating behaviors, including restrictive eating and compensatory behaviors, may be due to the traditional definition of food craving as the desire to consume particular foods. Applying motivational models of substance use craving to food craving may help to explain inconsistencies within existing literature. Three motivational models of craving from the substance use literature may be particularly applicable to (1) provide a clear definition of food craving as a motivational process, (2) understand the role of that motivational process as it underlies the full spectrum of disordered eating behavioral patterns, (3) provide insight for the most appropriate ways in which to accurately assess food craving, and (4) establish ways in which food craving may represent a useful motivational process to target in eating disorder treatments. This narrative review describes three models of substance use craving and provides suggestions for utilizing motivational models to understand the transdiagnostic role of food craving as it relates to the full spectrum of disordered eating behaviors in both research and clinical work.

Changes in Brain-derived Neurotrophic Factor From Active and Sham Transcranial Direct Current Stimulation in Older Adults With Knee Osteoarthritis

OBJECTIVES

Previous work has shown effects of transcranial direct current stimulation (tDCS) on clinical pain measures, qualitative sensory testing measures, and peripheral inflammation. The present report extends this research to investigate the effect of tDCS on brain-derived neurotrophic factor (BDNF) levels.

MATERIALS AND METHODS

This secondary analysis examined a sample of 40 older adults (50 to 70 y old) with symptomatic knee osteoarthritis randomly assigned in a 1:1 fashion to active (n=20) or sham (n=20) tDCS for 20 minutes on 5 consecutive days. BDNF was measured before the first session and after the final treatment session. Generalized linear modeling evaluated BDNF plasma levels as a function of tDCS group, adjusted for baseline. Bayesian statistical inference was used to quantify the probability that effects of the treatment exist.

RESULTS

Generalized linear modeling indicated a 90.4% posterior probability that the sham condition had 49.9% higher BDNF at the end of treatment, controlling for baseline. Follow-up analyses within the active TDCS group supported an association between change in BDNF and change in clinical pain, and exploratory analyses found an effect of tDCS on irisin.

DISCUSSION

Results indicated that tDCS could be a potential nonpharmacological treatment to decrease BDNF levels, which may in turn decrease pain. This study adds to a growing literature suggesting that tDCS affects cortical excitability, and consequentially, the neural circuits implicated in pain modulation. In addition to a direct connection to analgesia, BDNF changes may reflect tDCS-induced changes in different cortical areas and/or neural circuits.

Targeting white matter neuroprotection as a relapse prevention strategy for treatment of cocaine use disorder: Design of a mechanism-focused randomized clinical trial

Cocaine use continues to be a significant public health problem with limited treatment options and no approved pharmacotherapies. Cognitive-behavioral therapy (CBT) remains the mainstay treatment for preventing relapse, however, people with chronic cocaine use display cognitive impairments that are associated with poor response to CBT. Emerging evidence in animal and human studies suggests that the peroxisome proliferator-activated receptor-gamma (PPAR- γ) agonist, pioglitazone, improves white matter integrity that is essential for cognitive function. This project will determine whether adjunctive use of pioglitazone enhances the effect of CBT in preventing relapse during the early phase of recovery from cocaine use disorder. This paper describes the design of a mechanism-focused phase 2 randomized clinical trial that aims first to evaluate the effects of pioglitazone on targeted mechanisms related to white matter integrity, cognitive function, and cocaine craving; and second, to evaluate the extent to which improvements on target mechanisms predict CBT response. Positive results will support pioglitazone as a potential cognitive enhancing agent to advance to later stage medication development research.

Repurposing Peroxisome Proliferator-Activated Receptor Agonists in Neurological and Psychiatric Disorders

Common pathophysiological mechanisms have emerged for different neurological and neuropsychiatric conditions. In particular, mechanisms of oxidative stress, immuno-inflammation, and altered metabolic pathways converge and cause neuronal and non-neuronal maladaptative phenomena, which underlie multifaceted brain disorders. The peroxisome proliferator-activated receptors (PPARs) are nuclear receptors modulating, among others, anti-inflammatory and neuroprotective genes in diverse tissues. Both endogenous and synthetic PPAR agonists are approved treatments for metabolic and systemic disorders, such as diabetes, fatty liver disease, and dyslipidemia(s), showing high tolerability and safety profiles. Considering that some PPAR-acting drugs permeate through the blood-brain barrier, the possibility to extend their scope from the periphery to central nervous system has gained interest in recent years. Here, we review preclinical and clinical evidence that PPARs possibly exert a neuroprotective role, thereby providing a rationale for repurposing PPAR-targeting drugs to counteract several diseases affecting the central nervous system.

Decreased cocaine demand following contingency management treatment

A hypothetical cocaine purchasing task (CocPT) was used to assess changes in cocaine demand in the context of contingency management (CM) treatment for cocaine use disorder (CUD). Participants (N = 89) were treatment-seeking individuals with CUD receiving 4 weeks of abstinence-based, high-magnitude CM. Treatment response (vs. non-response) was operationally defined as the submission of 6 consecutive cocaine-negative urine samples across two weeks. The CPT was assessed at baseline, week 2, and week 5. Demand data were well described by the exponentiated demand model, and baseline demand indices (Q0, Pmax, breakpoint, essential value) were significantly associated with self-report measures of cocaine use. The probability of being a zero-responder reporting zero cocaine consumption at all prices significantly increased over the course of treatment, and was greater among treatment responders vs. non-responders. Among non-zero demand data, decreases in Omax, Pmax, breakpoint, and essential value were observed over the course of CM treatment, favoring responders. To our knowledge, this is the first study to assess change in cocaine demand in the context of CM treatment targeting cocaine abstinence. Our results support the utility of cocaine demand as a measure for both identifying individuals with greater treatment need and tracking relapse risk over the course of treatment.

Reduced alcohol use in patients prescribed pioglitazone

BACKGROUND AND OBJECTIVES

Alcohol use disorder (AUD) is common and causes significant morbidity and mortality. Currently approved medications are moderately effective. Novel medications are needed to address AUD. Preliminary data suggests pioglitazone may reduce alcohol use.

METHODS

Veterans seen at the Minneapolis VA Health Care System, who were prescribed pioglitazone for diabetes between October 1, 2015 and September 30, 2016, were identified using a national VA database (N = 49). Further chart review was performed to identify all Alcohol Use Disorder Identification Test-Consumption (AUDIT-C) scores prior to starting pioglitazone. Hierarchical Linear models were used to compare all AUDIT-C scores on and off pioglitazone and compare the change in AUDIT-C scores over time before and during pioglitazone was prescribed. AUDIT-C scores were nested within subject with fixed effects for pioglitazone and random intercept and slope for time.

RESULTS

Forty-nine patients were prescribed pioglitazone and had AUDIT-C scores of 3 or more. The estimated mean AUDIT-C score prior to receiving pioglitazone was 3.98 (95% confidence interval [CI]: 3.51-4.44) and this was reduced to 2.89 (95% CI: 2.46-3.32), reflecting a significant change F(1, 323) = 43.3, p < .001 in the score. The primary reduction occurred within the first year of the pioglitazone prescription. This effect remained significant after controlling for age.

CONCLUSION AND SCIENTIFIC SIGNIFICANCE

This is the first study of pioglitazone used in a clinical sample focused on alcohol use outcome. The data show that pioglitazone may reduce alcohol use in patients with heavy drinking. Clinical trials of pioglitazone are warranted in patients with AUD.

Assessment of demand for methamphetamine and cigarettes among individuals with methamphetamine use disorder

Methamphetamine (MA) is a highly addictive stimulant with recent upward trends in prevalence and associated public health problems. Drug demand, as assessed by hypothetical purchasing tasks, has been useful in addictions research and may help our understanding of the factors influencing MA use. However, no studies have assessed MA demand using current models of demand. The purpose of the current study was to assess demand for MA using a hypothetical drug purchasing task. Given high rates of cigarette smoking among MA users, it was of interest also to assess and compare demand for MA relative to cigarettes. Participants consisted of non-treatment-seeking volunteers with MA use disorder (N = 18), of whom 17 reported daily smoking. Results showed the exponentiated demand model provided a good fit to consumption data. Results from Bayesian generalized linear modeling demonstrated multiple positive relationships (posterior probability ≥75%) between self-reported drug use (days MA used in the past 30 days, cigarettes smoked per day) and indices of demand for each drug (Qo, Omax, Pmax, and break point). Comparing MA to cigarettes, results from Bayesian generalized linear mixed modeling revealed greater abuse liability for MA compared to cigarettes (posterior probability ≥99%) based on α and essential value. Overall, the findings of the current study support the feasibility and validity of the exponentiated demand model for assessing demand for drugs among individuals with MA use disorder. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The effects of combination levodopa-ropinirole on cognitive improvement and treatment outcome in individuals with cocaine use disorder: A bayesian mediation analysis

BACKGROUND

Chronic cocaine users show impairments in cognitive processes associated with dopamine (DA) circuitry. Medications aimed at bolstering cognitive functions via DA modulation might enhance treatment outcome.

METHODS

The trial used a double-blind, double-dummy, parallel-group design with four treatment arms comparing placebo (PLC) to levodopa/carbidopa 800 mg/200 mg alone (LR0), levodopa plus extended release (XR) ropinirole 2 mg (LR2) or XR ropinirole 4 mg (LR4). Adults (n = 110) with cocaine use disorder attended thrice weekly clinic visits for 10 weeks. Potential cognitive mediators assessed at week 5 consisted of measures of decision-making (Iowa Gambling Task, Risky Decision-Making Task), attention/impulsivity (Immediate Memory Task), motivation (Progressive Ratio task), and cognitive control (Cocaine Stoop task). The primary outcome measure was the treatment effectiveness score (TES) calculated as the number of cocaine-negative urines collected from weeks 6-10.

RESULTS

Bayesian mediation examined indirect and total effects of the relationships between each active treatment (compared to PLC) and TES. Total (direct) effects were supported for LR0 and LR2, but not for LR4. Indirect effects were tested for each mediator. Notably, 22.3 % and 35.4 % of the total effects of LR0 and LR2 on TES were mediated by changes in attention/impulsivity.

CONCLUSIONS

The hypothesized mediation effect was strongest for levodopa plus 2 mg ropinirole, indicating that this DA medication combination predicted change (improvement) in attention/impulsivity, which in turn predicted change (reduction) in cocaine use. This finding provides modest support for cognitive enhancement as a target for medications to treat cocaine use disorder.

The (Poly)Pharmacology of Cannabidiol in Neurological and Neuropsychiatric Disorders: Molecular Mechanisms and Targets

Cannabidiol (CBD), the major nonpsychoactive Cannabis constituent, has been proposed for the treatment of a wide panel of neurological and neuropsychiatric disorders, including anxiety, schizophrenia, epilepsy and drug addiction due to the ability of its versatile scaffold to interact with diverse molecular targets that are not restricted to the endocannabinoid system. Albeit the molecular mechanisms responsible for the therapeutic effects of CBD have yet to be fully elucidated, many efforts have been devoted in the last decades to shed light on its complex pharmacological profile. In particular, an ever-increasing number of molecular targets linked to those disorders have been identified for this phytocannabinoid, along with the modulatory effects of CBD on their cascade signaling. In this view, here we will try to provide a comprehensive and up-to-date overview of the molecular basis underlying the therapeutic effects of CBD involved in the treatment of neurological and neuropsychiatric disorders.

Exenatide Adjunct to Nicotine Patch Facilitates Smoking Cessation and May Reduce Post-Cessation Weight Gain: A Pilot Randomized Controlled Trial

INTRODUCTION

Approved pharmacological treatments for smoking cessation are modestly effective, underscoring the need for improved pharmacotherapies. Glucagon-like peptide-1 receptor (GLP-1R) agonists attenuate the rewarding effects of nicotine in preclinical studies. We examined the efficacy of extended-release exenatide, a GLP-1R agonist, combined with nicotine replacement therapy (NRT, patch) for smoking cessation, craving, and withdrawal symptoms, with post-cessation body weight as a secondary outcome.

METHODS

Eighty-four prediabetic and/or overweight smokers were randomized (1 : 1) to once-weekly placebo or exenatide, 2 mg, subcutaneously. All participants received NRT (21 mg) and brief smoking cessation counseling. Seven-day point prevalence abstinence (expired CO level ≤5 ppm), craving, withdrawal, and post-cessation body weight were assessed following 6 weeks of treatment. A Bayesian approach for analyzing generalized linear models yielded posterior probabilities (PP) to quantify the evidence favoring hypothesized effects of treatment on the study outcomes.

RESULTS

Exenatide increased the risk for smoking abstinence compared to placebo (46.3% and 26.8%, respectively), (risk ratio [RR] = 1.70; 95% credible interval = [0.96, 3.27]; PP = 96.5%). Exenatide reduced end-of-treatment craving in the overall sample and withdrawal among abstainers. Post-cessation body weight was 5.6 pounds lower in the exenatide group compared to placebo (PP = 97.4%). Adverse events were reported in 9.5% and 2.3% of participants in the exenatide and placebo groups, respectively.

CONCLUSIONS

Exenatide, in combination with the NRT improved smoking abstinence, reduced craving and withdrawal symptoms, and decreased weight gain among abstainers. Findings suggest that the GLP-1R agonist strategy is worthy of further research in larger, longer duration studies.

IMPLICATIONS

Despite considerable progress in tobacco control, cigarette smoking remains the leading cause of preventable disease, disability, and death. In this pilot study, we showed that extended-release exenatide, a glucagon-like peptide-1 receptor agonist, added to the nicotine patch, improved abstinence and mitigated post-cessation body weight gain compared to patch alone. Further research is needed to confirm these initial positive results.

A meta-analysis of tract-based spatial statistics studies examining white matter integrity in cocaine use disorder

Tract-based spatial statistics (TBSS) of diffusion tensor imaging (DTI) studies have consistently shown diminished white matter (WM) integrity for individuals with cocaine use disorder (CUD). The present study used seed-based d mapping (SDM) to determine the extent to which a systematic difference in the WM integrity of cocaine users may exist (as compared with that of healthy controls). Articles from 2006 (when TBSS was first developed) to present were reviewed, with eight selected for inclusion. Meta-analysis found lower fractional anisotropy (FA) in the genu of the corpus callosum for cocaine users, with a small-to-moderate peak effect size (Hedge's g = -0.331). Sensitivity analyses mostly supported the robustness of the obtained difference. Differences detected at exploratory thresholds for significance suggested insult to WM integrity extending beyond the corpus callosum. The present results compliment a previous region-of-interest (ROI)-based meta-analysis of DTI studies in individuals with CUD. These findings have significant implications for the potential role of neuroprotective agents in the treatment of CUD and merit additional iteration as more studies accrue in the literature.

Energy sensors in drug addiction: A potential therapeutic target

Addiction is defined as the repeated exposure and compulsive seek of psychotropic drugs that, despite the harmful effects, generate relapse after the abstinence period. The psychophysiological processes associated with drug addiction (acquisition/expression, withdrawal, and relapse) imply important alterations in neurotransmission and changes in presynaptic and postsynaptic plasticity and cellular structure (neuroadaptations) in neurons of the reward circuits (dopaminergic neuronal activity) and other corticolimbic regions. These neuroadaptation mechanisms imply important changes in neuronal energy balance and protein synthesis machinery. Scientific literature links drug-induced stimulation of dopaminergic and glutamatergic pathways along with presence of neurotrophic factors with alterations in synaptic plasticity and membrane excitability driven by metabolic sensors. Here, we provide current knowledge of the role of molecular targets that constitute true metabolic/energy sensors such as AMPK, mTOR, ERK, or K_ATP in the development of the different phases of addiction standing out the main brain regions (ventral tegmental area, nucleus accumbens, hippocampus, and amygdala) constituting the hubs in the development of addiction. Because the available treatments show very limited effectiveness, evaluating the drug efficacy of AMPK and mTOR specific modulators opens up the possibility of testing novel pharmacotherapies for an individualized approach in drug abuse.

Beta-caryophyllene inhibits cocaine addiction-related behavior by activation of PPARα and PPARγ: repurposing a FDA-approved food additive for cocaine use disorder

Cocaine abuse continues to be a serious health problem worldwide. Despite intense research, there is still no FDA-approved medication to treat cocaine use disorder (CUD). In this report, we explored the potential utility of beta-caryophyllene (BCP), an FDA-approved food additive for the treatment of CUD. We found that BCP, when administered intraperitoneally or intragastrically, dose-dependently attenuated cocaine self-administration, cocaine-conditioned place preference, and cocaine-primed reinstatement of drug seeking in rats. In contrast, BCP failed to alter food self-administration or cocaine-induced hyperactivity. It also failed to maintain self-administration in a drug substitution test, suggesting that BCP has no abuse potential. BCP was previously reported to be a selective CB2 receptor agonist. Unexpectedly, pharmacological blockade or genetic deletion of CB1, CB2, or GPR55 receptors in gene-knockout mice failed to alter BCP's action against cocaine self-administration, suggesting the involvement of non-CB1, non-CB2, and non-GPR55 receptor mechanisms. Furthermore, pharmacological blockade of μ opioid receptor or Toll-like receptors complex failed to alter, while blockade of peroxisome proliferator-activated receptors (PPARα, PPARγ) reversed BCP-induced reduction in cocaine self-administration, suggesting the involvement of PPARα and PPARγ in BCP's action. Finally, we used electrical and optogenetic intracranial self-stimulation (eICSS, oICSS) paradigms to study the underlying neural substrate mechanisms. We found that BCP is more effective in attenuation of cocaine-enhanced oICSS than eICSS, the former driven by optical activation of midbrain dopamine neurons in DAT-cre mice. These findings indicate that BCP may be useful for the treatment of CUD, likely by stimulation of PPARα and PPARγ in the mesolimbic system.

Functional interactions between cannabinoids, omega-3 fatty acids, and peroxisome proliferator-activated receptors: Implications for mental health pharmacotherapies

Cannabis contains a plethora of phytochemical constituents with diverse neurobiological effects. Cannabidiol (CBD) is the main non-psychotropic component found in cannabis that is capable of modulating mesocorticolimbic DA transmission and may possess therapeutic potential for several neuropsychiatric disorders. Emerging evidence also suggests that, similar to CBD, omega-3 polyunsaturated fatty acids may regulate DA transmission and possess therapeutic potential for similar neuropsychiatric disorders. Although progress has been made to elucidate the mechanisms underlying the therapeutic properties of CBD and omega-3s, it remains unclear through which receptor mechanisms they may produce their purported effects. Peroxisome proliferator-activated receptors are a group of nuclear transcription factors with multiple isoforms. PPARγ is an isoform activated by both CBD and omega-3, whereas the PPARα isoform is activated by omega-3. Interestingly, the activation of PPARγ and PPARα with selective agonists has been shown to decrease mesocorticolimbic DA activity and block neuropsychiatric symptoms similar to CBD and omega-3s, raising the possibility that CBD and omega-3s produce their effects through PPAR signaling. This review will examine the relationship between CBD, omega-3s, and PPARs and how they may be implicated in the modulation of mesocorticolimbic DAergic abnormalities and associated neuropsychiatric symptoms.

Potential of Glial Cell Modulators in the Management of Substance Use Disorders

The pervasive and devastating nature of substance use disorders underlies the need for the continued development of novel pharmacotherapies. We now know that glia play a much greater role in neuronal processes than once believed.  The various types of glial cells (e.g., astrocytes, microglial, oligodendrocytes) participate in numerous functions that are crucial to healthy central nervous system function. Drugs of abuse have been shown to interact with glia in ways that directly contribute to the pharmacodynamic effects responsible for their abuse potential. Through their effect upon glia, drugs of abuse also alter brain function resulting in behavioral changes associated with substance use disorders. Therefore, drug-induced changes in glia and inflammation within the central nervous system (neuroinflammation) have been investigated to treat various aspects of drug abuse and dependence. This article presents a brief overview of the effects of each of the major classes of addictive drugs on glia. Next, the paper reviews the pre-clinical and clinical studies assessing the effects that glial modulators have on abuse-related behavioral effects, such as pleasure, withdrawal, and motivation. There is a strong body of pre-clinical literature demonstrating the general effectiveness of several glia-modulating drugs in models of reward and relapse. Clinical studies have also yielded promising results, though not as robust. There is still much to disentangle regarding the integration between addictive drugs and glial cells. Improved understanding of the relationship between glia and the pathophysiology of drug abuse should allow for more precise exploration in the development and testing of glial-directed treatments for substance use disorders.

Therapeutic Potential of Peroxisome Proliferator-Activated Receptor (PPAR) Agonists in Substance Use Disorders: A Synthesis of Preclinical and Human Evidence

Targeting peroxisome proliferator-activated receptors (PPARs) has received increasing interest as a potential strategy to treat substance use disorders due to the localization of PPARs in addiction-related brain regions and the ability of PPAR ligands to modulate dopamine neurotransmission. Robust evidence from animal models suggests that agonists at both the PPAR-α and PPAR-γ isoforms can reduce both positive and negative reinforcing properties of ethanol, nicotine, opioids, and possibly psychostimulants. A reduction in the voluntary consumption of ethanol following treatment with PPAR agonists seems to be the most consistent finding. However, the human evidence is limited in scope and has so far been less promising. There have been no published human trials of PPAR agonists for treatment of alcohol use disorder, despite the compelling preclinical evidence. Two trials of PPAR-α agonists as potential smoking cessation drugs found no effect on nicotine-related outcomes. The PPAR-γ agonist pioglitazone showed some promise in reducing heroin, nicotine, and cocaine craving in two human laboratory studies and one pilot trial, yet other outcomes were unaffected. Potential explanations for the discordance between the animal and human evidence, such as the potency and selectivity of PPAR ligands and sex-related variability in PPAR physiology, are discussed.

Elevated Neutrophil to Lymphocyte Ratio in Older Adults with Cocaine Use Disorder as a Marker of Chronic Inflammation

Objective

The neutrophil to lymphocyte ratio (NLR) is a non-specific, easy-to-obtain marker of inflammation associated with morbidity and mortality in systemic, psychiatric, and age-related inflammatory conditions. Given the growing trend of substance use disorder (SUD) in older adults, and the relationship between inflammation and SUD elevated NLR may serve as a useful inflammatory biomarker of the combined burden of aging and SUD. The present study focused on cocaine use disorder (CUD) to examine if cocaine adds further inflammatory burden among older adults, by comparing NLR values between older adults with CUD and a non-cocaine using, aged-matched, nationally representative sample.

Methods

The dataset included 107 (86% male) participants (aged 50-65 years) with cocaine use disorder. NLR was derived from complete blood count tests by dividing the absolute value of peripheral neutrophil concentration by lymphocyte concentration. For comparison, we extracted data from age-matched adults without CUD using the National Health and Nutrition Examination Survey. Individuals with immunocompromising conditions were excluded (e.g., rheumatoid arthritis and sexually transmitted infections such as HIV). A doubly-robust inverse probability-weighted regression adjustment (IPWRA) propensity score method was used to estimate group differences on NLR while controlling for potential confounding variables (age, gender, race, income, nicotine, marijuana and alcohol use).

Results

The IPWRA model revealed that the CUD sample had significantly elevated NLR in comparison to non-cocaine users, with a moderate effect size (β weight = 0.67).

Conclusion

Although non-specific, NLR represents a readily obtainable inflammatory marker for SUD research. CUD may add further inflammatory burden to aging cocaine users.

Proactive delivery of nicotine replacement therapy to families of hospitalized infants in a NICU: A randomized controlled pilot trial

Neonatal ICU (NICU) hospitalizations provide opportunities to engage individuals/families who smoke with evidence-based cessation treatments to protect infants from tobacco smoke exposure. The aim of this pilot study was to establish the feasibility and potential efficacy of providing motivational advice and NRT (MA+NRT) to families of NICU infants. RCT methodology equally allocated participants who reported ≥1 household smoker (N=32) from a large NICU to MA+NRT or referral to a Quitline. The primary outcome was accepting NRT patches (MA+NRT) and use of NRT. Bayesian analyses modeled NRT use as a function of treatment group. Most MA+NRT participants (81.3%; n=13) accepted the patches. No Quitline participants called the Quitline. NRT use differed across groups, indicating a 0.907 posterior probability that a positive effect for MA+NRT exists (RR=2.32, 95% CI=[0.68-11.34]). This study demonstrated feasibility and acceptability for offering NRT and motivational advice to NICU parents and supports further intervention refinement with NICU families.

Tapering with Pharmaceutical GHB or Benzodiazepines for Detoxification in GHB-Dependent Patients: A Matched-Subject Observational Study of Treatment-as-Usual in Belgium and The Netherlands

BACKGROUND

The gamma-hydroxybutyric acid (GHB) withdrawal syndrome often has a fulminant course, with a rapid onset and swift progression of severe complications. In clinical practice, two pharmacological regimens are commonly used to counteract withdrawal symptoms during GHB detoxification: tapering with benzodiazepines (BZDs) or tapering with pharmaceutical GHB. In Belgium, standard treatment is tapering with BZDs, while in the Netherlands, pharmaceutical GHB is the preferred treatment method. Though BZDs are cheaper and readily available, case studies suggest GHB tapering results in less severe withdrawal and fewer complications.

OBJECTIVES

This study aimed to compare two treatments-as-usual in tapering methods on withdrawal, craving and adverse events during detoxification in GHB-dependent patients.

METHODS

In this multicentre non-randomised indirect comparison of two treatments-as-usual, patients with GHB dependence received BZD tapering (Belgian sample: n = 42) or GHB tapering (Dutch sample: n = 42, matched historical sample). Withdrawal was assessed using the Subjective and Objective Withdrawal Scales, craving was assessed with a Visual Analogue Scale and adverse events were systematically recorded. Differences in withdrawal and craving were analysed using a linear mixed-model analysis, with 'days in admission' and 'detoxification method' as fixed factors. Differences in adverse events were analysed using a Chi-square analysis.

RESULTS

Withdrawal decreased over time in both groups. Withdrawal severity was higher in patients receiving BZD tapering (subjective mean = 36.50, standard deviation = 21.08; objective mean = 8.05, standard deviation = 4.68) than in patients receiving pharmaceutical GHB tapering (subjective mean = 15.90; standard deviation = 13.83; objective mean = 3.72; standard deviation = 2.56). No differences in craving were found. Adverse events were more common in the BZD than the GHB group, especially delirium (20 vs 2.5%, respectively).

CONCLUSIONS

These results support earlier work that BZD tapering might not always sufficiently dampen withdrawal in GHB-dependent patients. However, it needs to be taken into account that both treatments were assessed in separate countries. Based on the current findings, tapering with pharmaceutical GHB could be considered for patients with GHB dependence during detoxification, as it has potentially less severe withdrawal and fewer complications than BZD tapering.

Pharmacotherapy for Cocaine Use Disorder-a Systematic Review and Meta-analysis

BACKGROUND

Currently, there are no accepted FDA-approved pharmacotherapies for cocaine use disorder, though numerous medications have been tested in clinical trials. We conducted a systematic review and meta-analysis to better understand the effectiveness of pharmacotherapy for cocaine use disorder.

METHODS

We searched multiple data sources (MEDLINE, PsycINFO, and Cochrane Library) through November 2017 for systematic reviews and randomized controlled trials (RCTs) of pharmacological interventions in adults with cocaine use disorder. When possible, we combined the findings of trials with comparable interventions and outcome measures in random-effects meta-analyses. We assessed the risk of bias of individual trials and the strength of evidence for each outcome using standardized criteria. Outcomes included continuous abstinence (3+ consecutive weeks); cocaine use; harms; and study retention. For relapse prevention studies (participants abstinent at baseline), we examined lapse (first cocaine positive or missing UDS) and relapse (two consecutive cocaine positive or missed UDS').

RESULTS

Sixty-six different drugs or drug combinations were studied in seven systematic reviews and 48 RCTs that met inclusion criteria. Antidepressants were the most widely studied drug class (38 RCTs) but appear to have no effect on cocaine use or treatment retention. Increased abstinence was found with bupropion (2 RCTs: RR 1.63, 95% CI 1.02 to 2.59), topiramate (2 RCTs: RR 2.56, 95% CI 1.39 to 4.73), and psychostimulants (14 RCTs: RR 1.36, 95% CI 1.05 to 1.77), though the strength of evidence for these findings was low. We found moderate strength of evidence that antipsychotics improved treatment retention (8 RCTs: RR 1.33, 95% CI 1.03 to 1.75).

DISCUSSION

Most of the pharmacotherapies studied were not effective for treating cocaine use disorder. Bupropion, psychostimulants, and topiramate may improve abstinence, and antipsychotics may improve retention. Contingency management and behavioral interventions along with pharmacotherapy should continue to be explored.

SR REGISTRATION

Prospero CRD42018085667.

Activation of PPARγ Attenuates the Expression of Physical and Affective Nicotine Withdrawal Symptoms through Mechanisms Involving Amygdala and Hippocampus Neurotransmission

An isoform of peroxisome proliferator-activated receptors (PPARs), PPARγ, is the receptor for the thiazolidinedione class of anti-diabetic medications including pioglitazone. Neuroanatomical data indicate PPARγ localization in brain areas involved in drug addiction. Preclinical and clinical data have shown that pioglitazone reduces alcohol and opioid self-administration, relapse to drug seeking, and plays a role in emotional responses. Here, we investigated the behavioral effect of PPARγ manipulation on nicotine withdrawal in male Wistar rats and in male mice with neuron-specific PPARγ deletion (PPARγ^(-/-)) and their littermate wild-type (PPARγ^(+/+)) controls. Real-time quantitative RT-PCR and RNAscope in situ hybridization assays were used for assessing the levels of expression and cell-type localization of PPARγ during nicotine withdrawal. Brain site-specific microinjections of the PPARγ agonist pioglitazone were performed to explore the role of this system on nicotine withdrawal at a neurocircuitry level. Results showed that activation of PPARγ by pioglitazone abolished the expression of somatic and affective nicotine withdrawal signs in rats and in (PPARγ^(+/+)) mice. This effect was blocked by the PPARγ antagonist GW9662. During early withdrawal and protracted abstinence, the expression of PPARγ increased in GABAergic and glutamatergic cells of the amygdala and hippocampus, respectively. Hippocampal microinjections of pioglitazone reduced the expression of the physical signs of withdrawal, whereas excessive anxiety associated with protracted abstinence was prevented by pioglitazone microinjection into the amygdala. Our results demonstrate the implication of the neuronal PPARγ in nicotine withdrawal and indicates that activation of PPARγ may offer an interesting strategy for smoking cessation.SIGNIFICANCE STATEMENT Smoking cessation leads the occurrence of physical and affective withdrawal symptoms representing a major burden to quit tobacco use. Here, we show that activation of PPARγ prevents the expression of both somatic and affective signs of nicotine withdrawal. At molecular levels results show that PPARγ expression increases in GABAergic cells in the hippocampus and in GABA- and glutamate-positive cells in the basolateral amygdala. Hippocampal microinjections of pioglitazone reduce the insurgence of the physical withdrawal signs, whereas anxiety linked to protracted abstinence is attenuated by pioglitazone injected into the amygdala. Our results demonstrate the implication of neuronal PPARγ in nicotine withdrawal and suggest that PPARγ agonism may represent a promising treatment to aid smoking cessation.

Exploration and Development of PPAR Modulators in Health and Disease: An Update of Clinical Evidence

Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that govern the expression of genes responsible for energy metabolism, cellular development, and differentiation. Their crucial biological roles dictate the significance of PPAR-targeting synthetic ligands in medical research and drug discovery. Clinical implications of PPAR agonists span across a wide range of health conditions, including metabolic diseases, chronic inflammatory diseases, infections, autoimmune diseases, neurological and psychiatric disorders, and malignancies. In this review we aim to consolidate existing clinical evidence of PPAR modulators, highlighting their clinical prospects and challenges. Findings from clinical trials revealed that different agonists of the same PPAR subtype could present different safety profiles and clinical outcomes in a disease-dependent manner. Pemafibrate, due to its high selectivity, is likely to replace other PPARα agonists for dyslipidemia and cardiovascular diseases. PPARγ agonist pioglitazone showed tremendous promises in many non-metabolic disorders like chronic kidney disease, depression, inflammation, and autoimmune diseases. The clinical niche of PPARβ/δ agonists is less well-explored. Interestingly, dual- or pan-PPAR agonists, namely chiglitazar, saroglitazar, elafibranor, and lanifibranor, are gaining momentum with their optimistic outcomes in many diseases including type 2 diabetes, dyslipidemia, non-alcoholic fatty liver disease, and primary biliary cholangitis. Notably, the preclinical and clinical development for PPAR antagonists remains unacceptably deficient. We anticipate the future design of better PPAR modulators with minimal off-target effects, high selectivity, superior bioavailability, and pharmacokinetics. This will open new possibilities for PPAR ligands in medicine.

Drugs of Abuse Induced-Subversion of the Peripheral Immune Response and Central Glial Activity: Focus on Novel Therapeutic Approaches

BACKGROUND

Drugs of abuse affect both central nervous system (CNS) and peripheral immune function. Besides the involvement of dopamine and glutamate systems, chronic exposure to drugs of abuse alters immune homeostasis, promoting a pro-inflammatory status. At the same time, impaired peripheral immunity leads to an increased susceptibility to infections in drug abusers.

DISCUSSION

There is evidence that certain drugs, such as opioids, activate microglial cells and astrocytes which, in turn, provoke central neuroinflammation. Particularly, opioids bind the Toll-like receptor (TLR)-4 with increased expression of nuclear factor kappa-light-chain-enhancer of activated B cells and release of pro-inflammatory cytokines. Peripheral mediators released by immune cells also contribute to aggravate central neuroinflammation.

CONCLUSION

These are based either on the inhibition of TLR-4 activation by drugs of abuse or on the correction of dopamine and glutamate pathways. Finally, a hypothetic nutraceutical intervention with polyphenols in view of their anti-inflammatory and anti-oxidant properties will be outlined as an adjuvant treatment for drugs of abuse-related disorders.

The Effect of Transcranial Direct Current Stimulation on Inflammation in Older Adults With Knee Osteoarthritis: A Bayesian Residual Change Analysis

Transcranial direct current stimulation (tDCS) has demonstrated effectiveness in reducing clinical and experimental measures of pain in patients with chronic pain; however, research examining the mechanisms of action for the effects of tDCS has been lacking. The present study investigated the effect of active tDCS on measures of inflammation and stress. Older adults (aged 50-70 years) with knee osteoarthritis (OA) were randomly assigned to receive daily 20-min sessions of either tDCS (n = 20) or sham tDCS (n = 20) for 5 consecutive days. Participants provided blood samples at baseline and the end of treatment. The following measures of immune function and stress were collected: interleukin (IL)-6 and 10, tumor necrosis factor-α (TNF-α), C-reactive protein, cortisol, and β-endorphin. Generalized linear modeling evaluated each posttreatment measure as a function of tDCS group, controlling for baseline (measuring residual change, analogous to analysis of covariance). Bayesian statistical inference was used to directly quantify the probability of the effect of active tDCS. IL-6, IL-10, TNF-α, and β-endorphin demonstrated lower levels of stress and inflammation in the active tDCS group. These findings provide preliminary evidence that active (relative to sham) tDCS is associated with reduced levels of inflammation.

Regional differences in white matter integrity in stimulant use disorders: A meta-analysis of diffusion tensor imaging studies

BACKGROUND

Converging lines of evidence from diffusion tensor imaging (DTI) studies reveal significant alterations in white matter (WM) microstructure in the prefrontal cortex of chronic stimulant users compared to controls, suggesting compromised axonal microstructure and/or myelin.

METHODS

A meta-analysis of DTI-based WM integrity was conducted for white matter regions across the corpus callosum and association fibers. Articles were sourced and selected using PRISMA guidelines for systematic review and meta-analysis. Inclusion and exclusion criteria were determined by the authors in order to best capture WM integrity among individuals with primary stimulant use in comparison to healthy control subjects.

RESULTS

Eleven studies that focused on region-of-interest (ROI)-based analysis of WM integrity were extracted from an initial pool of 113 independent studies. Analysis across ROIs indicated significantly lower fractional anisotropy (FA) values in stimulant use groups compared to controls with a small to moderate overall effect (Hedges' g = -0.37, 95% CI [-0.54, -0.20]). Eigenvalues were also analyzed, revealing a significant effect for radial diffusivity (RD; Hedges' g = 0.24, 95% CI [0.01, 0.47]) but not axial diffusivity (AD; Hedges' g = 0.05, 95% CI [-0.20, 0.29]) or mean diffusivity (MD; Hedges' g = 0.20, 95% CI [-0.01, 0.41]). Subgroup analyses based on specific ROIs, primary substance use, poly-substance use, and imaging technology were also explored.

CONCLUSION

Results of the present study suggest a consistent effect of compromised WM integrity for individuals with stimulant use disorders. Furthermore, no significant differences were found between cocaine and methamphetamine-based groups.

Preliminary examination of the orexin system on relapse-related factors in cocaine use disorder

RATIONALE

Current evidence and literature reviews provide a strong justification for examining the orexin receptor (OXR) system as a therapeutic target in substance use disorders, including cocaine and other psychostimulants.

OBJECTIVES

In this preliminary, proof-of-concept examination of orexin modulation in humans with cocaine use disorder, we measured changes in domains tied to relapse: stress, sleep, cue reactivity, and inhibitory control. Additionally, mood symptoms (anxiety, depression), medication compliance, and side effects were assessed.

METHODS

Twenty non-treatment seeking subjects with cocaine use disorder (CUD) received either the OX₁R / OX₂R antagonist suvorexant PO or placebo at 10 PM daily for two weeks (10 mg week 1, 20 mg week 2). Using psychometrics, smart-watch actigraphy, a cold-pressor stress challenge, and eye-tracking technology, the following domains were examined: sleep, stress/anxiety, cue-reactivity (attentional bias, craving), and inhibitory control. Psychometric data were collected every M/W/F (7 time points). Laboratory data were collected weekly (3 time points).

RESULTS

Bayesian and frequentist generalized linear models were employed in parallel to examine the effects of suvorexant compared to placebo, with a Bayesian posterior probability threshold >80% as evidence of a signal for suvorexant. Notable results favoring suvorexant over placebo included fewer total anti-saccade errors, improved sleep actigraphy (sleep/awake periods), pre/post cold-pressor change in heart rate and salivary cortisol (all posterior probabilities >94%), and craving (posterior probability >87%).

CONCLUSIONS

Initial but restricted evidence is provided supporting the orexin system as a modulator of relapse-related processes in cocaine use disorder. Baseline differences in the main outcome variables were not experimentally controlled and differences in craving were observed at baseline. This, in combination with a limited sample size, constrain the nature of the project. The results may serve to inform more comprehensive future research.

Cannabidiol Treatment Might Promote Resilience to Cocaine and Methamphetamine Use Disorders: A Review of Possible Mechanisms

Currently, there are no approved pharmacotherapies for addiction to cocaine and other psychostimulant drugs. Several studies have proposed that cannabidiol (CBD) could be a promising treatment for substance use disorders. In the present work, the authors describe the scarce preclinical and human research about the actions of CBD on the effects of stimulant drugs, mainly cocaine and methamphetamine (METH). Additionally, the possible mechanisms underlying the therapeutic potential of CBD on stimulant use disorders are reviewed. CBD has reversed toxicity and seizures induced by cocaine, behavioural sensitization induced by amphetamines, motivation to self-administer cocaine and METH, context- and stress-induced reinstatement of cocaine and priming-induced reinstatement of METH seeking behaviours. CBD also potentiated the extinction of cocaine- and amphetamine-induced conditioned place preference (CPP), impaired the reconsolidation of cocaine CPP and prevented priming-induced reinstatement of METH CPP. Observational studies suggest that CBD may reduce problems related with crack-cocaine addiction, such as withdrawal symptoms, craving, impulsivity and paranoia (Fischer et al., 2015). The potential mechanisms involved in the protective effects of CBD on addiction to psychostimulant drugs include the prevention of drug-induced neuroadaptations (neurotransmitter and intracellular signalling pathways changes), the erasure of aberrant drug-memories, the reversion of cognitive deficits induced by psychostimulant drugs and the alleviation of mental disorders comorbid with psychostimulant abuse. Further, preclinical studies and future clinical trials are necessary to fully evaluate the potential of CBD as an intervention for cocaine and methamphetamine addictive disorders.

Treating Hypertension in Children With n-of-1 Trials

OBJECTIVES

Clinicians prescribe antihypertensive medication to children with primary hypertension, but without data to define a particular choice as first-line therapy. A one-size-fits-all approach may not be appropriate for these patients. Our aim was to develop a personalized approach to hypertension treatment, using repeated ambulatory blood pressure monitoring (ABPM) in n-of-1 trials (single-patient randomized crossover trials).

METHODS

Children undergoing hypertension management at a single pediatric referral center were offered participation in an n-of-1 trial with repeated ABPM to compare 3 commonly used medications. The medication producing the greatest blood pressure reduction, and without unacceptable side effects, was selected as the preferred therapy for the individual.

RESULTS

Forty-two children agreed to participate; 7 were normotensive without medication; and 3 failed to complete one treatment cycle. Of the remaining 32 patients, lisinopril was preferred for 16, amlodipine for 8, hydrochlorothiazide for 4, and 4 had uncontrolled blood pressure on maximum doses of monotherapy. In conservative Bayesian analyses, the proportion of patients who preferred lisinopril was 49% (95% credible interval [CrI]: 32% to 69%), 24% (95% CrI: 12% to 41%) preferred amlodipine, and 12% (95% CrI: 4% to 26%) preferred hydrochlorothiazide. The preferred therapy for the majority (67%) of African American participants was lisinopril. Unacceptable side effects were reported in 24% of assessments for hydrochlorothiazide, 16% for lisinopril, and 13% for amlodipine.

CONCLUSIONS

No single medication was preferred for more than half of hypertensive children. n of-1 trials with repeated ABPM may promote better informed and individualized decisions in pediatric hypertension management.

Cigarette smoking, type 2 diabetes mellitus, and glucagon-like peptide-1 receptor agonists as a potential treatment for smokers with diabetes: An integrative review

Tobacco use disorder (TUD), in particular cigarette smoking, contributes significantly to the macro- and micro-vascular complications of type 2 diabetes mellitus (DM). Persons with DM who regularly use tobacco products are twice as likely to experience mortality and negative health outcomes. Despite these risks, TUD remains prevalent in persons with DM. The objective of this integrative review is to summarize the relationship between TUD and DM based on epidemiological and preclinical biological evidence. We conclude with a review of the literature on the glucagon-like peptide-1 (GLP-1) as a potential treatment target for addressing comorbid TUD in smokers with DM.

Neuroinflammation in addiction: A review of neuroimaging studies and potential immunotherapies

Addiction is a worldwide public health problem and this article reviews scientific advances in identifying the role of neuroinflammation in the genesis, maintenance, and treatment of substance use disorders. With an emphasis on neuroimaging techniques, this review examines human studies of addiction using positron emission tomography to identify binding of translocator protein (TSPO), which is upregulated in reactive glial cells and activated microglia during pathological states. High TSPO levels have been shown in methamphetamine use but exhibits variable patterns in cocaine use. Alcohol and nicotine use, however, are associated with lower TSPO levels. We discuss how mechanistic differences at the neurotransmitter and circuit level in the neural effects of these agents and subsequent immune response may explain these observations. Finally, we review the potential of anti-inflammatory drugs, including ibudilast, minocycline, and pioglitazone, to ameliorate the behavioral and cognitive consequences of addiction.

Measures of possible allostatic load in comorbid cocaine and alcohol use disorder: Brain white matter integrity, telomere length, and anti-saccade performance

Chronic cocaine and alcohol use impart significant stress on biological and cognitive systems, resulting in changes consistent with an allostatic load model of neurocognitive impairment. The present study measured potential markers of allostatic load in individuals with comorbid cocaine/alcohol use disorders (CUD/AUD) and control subjects. Measures of brain white matter (WM), telomere length, and impulsivity/attentional bias were obtained. WM (CUD/AUD only) was indexed by diffusion tensor imaging metrics, including radial diffusivity (RD) and fractional anisotropy (FA). Telomere length was indexed by the telomere to single copy gene (T/S) ratio. Impulsivity and attentional bias to drug cues were measured via eye-tracking, and were also modeled using the Hierarchical Diffusion Drift Model (HDDM). Average whole-brain RD and FA were associated with years of cocaine use (R2 = 0.56 and 0.51, both p < .005) but not years of alcohol use. CUD/AUD subjects showed more anti-saccade errors (p < .01), greater attentional bias scores (p < .001), and higher HDDM drift rates on cocaine-cue trials (Bayesian probability CUD/AUD > control = p > 0.99). Telomere length was shorter in CUD/AUD, but the difference was not statistically significant. Within the CUD/AUD group, exploratory regression using an elastic-net model determined that more years of cocaine use, older age, larger HDDM drift rate differences and shorter telomere length were all predictive of WM as measured by RD (model R2 = 0.79). Collectively, the results provide modest support linking CUD/AUD to putative markers of allostatic load.