Psychiatric diagnoses of treatment-seeking cocaine abusers

Natural products as the therapeutic strategies for addiction

World Drug Report 2023 concluded that 296 million people abused drugs, 39.5 million became addiction and 494,000 died as a direct or indirect result of addiction. Addiction has become a growing problem that affects individuals, their families, societies, countries and even the world. However, treatment for addiction is only limited to some developed countries because of the high cost, difficult implementation, and time consuming. Therefore, there is an urgent need to develop a low-cost, effective drug for the development of addiction treatment in more countries, which is essential for the stability and sustainable development of the world. In this review, it provided an overview of the abuse of common addictive drugs, related disorders, and current therapeutic regimen worldwide, and summarized the mechanisms of drug addiction as reward circuits, neuroadaptation and plasticity, cognitive decision-making, genetics, and environment. According to their chemical structure, 43 natural products and 5 herbal combinations with potential to treat addiction were classified, and their sources, pharmacological effects and clinical trials were introduced. It was also found that mitragine, ibogine, L-tetrahydropalmatine and crocin had greater potential for anti-addiction.

Sex-Dependent Differences in the Neural Correlates of Cocaine and Emotional Cue-Reactivity in Regular Cocaine Users and Non-Drug-Using Controls: Understanding the Role of Duration and Severity of Use

INTRODUCTION

The development of cocaine use disorder in females is suggested to be more strongly related to neural mechanisms underlying stress-reactivity, whereas in males it is suggested to be more strongly related to neural mechanisms underlying drug cue-reactivity. Existing evidence, however, is based on neuroimaging studies that either lack a control group and/or have very small sample sizes that do not allow to investigate sex differences.

METHODS

The main objective of the current study was to investigate sex differences in the neural correlates of cocaine and negative emotional cue-reactivity within high-risk intranasal cocaine users (CUs: 31 males and 26 females) and non-cocaine-using controls (non-CUs: 28 males and 26 females). A region of interest (ROI) analysis was applied to test for the main and interaction effects of group, sex, and stimulus type (cocaine cues vs. neutral cocaine cues and negative emotional cues vs. neutral emotional cues) on activity in the dorsal striatum, ventral striatum (VS), amygdala, and dorsal anterior cingulate cortex (dACC).

RESULTS

There were no significant sex or group differences in cocaine cue-reactivity in any of the ROIs. Results did reveal significant emotional cue-reactivity in the amygdala and VS, but these effects were not moderated by group or sex. Exploratory analyses demonstrated that emotional cue-induced activation of the dACC and VS was negatively associated with years of regular cocaine use in female CUs, while this relationship was absent in male CUs.

CONCLUSIONS

While speculative, the sex-specific associations between years of regular use and emotional cue-reactivity in the dACC and VS suggest that, with longer years of use, female CUs become less sensitive to aversive stimuli, including the negative consequences of cocaine use, which could account for the observed "telescoping effect" in female CUs.

Clinical management of psychostimulant withdrawal: review of the evidence

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

Naltrexone-bupropion combinations do not affect cocaine self-administration in humans

The FDA has not yet approved a pharmacotherapy for cocaine use disorder despite nearly four decades of research. This study determined the initial efficacy, safety, and tolerability of naltrexone-bupropion combinations as a putative pharmacotherapy for cocaine use disorder. Thirty-one (31) non-treatment seeking participants with cocaine use disorder completed a mixed-design human laboratory study. Participants were randomly assigned to the naltrexone conditions (i.e., 0, 50 mg/day; between-subject factor) and maintained on escalating doses of bupropion (i.e., 0, 100, 200, 400 mg/day; within-subject factor) for at least four days prior to the conduct of experimental sessions. Cocaine self-administration (IN, 0, 40, 80 mg) was then determined using a modified progressive ratio and relapse procedure. Subjective and cardiovascular effects were also measured. Cocaine produced prototypical dose-related increases in self-administration, subjective outcomes (e.g., "Like Drug"), and cardiovascular indices (e.g., heart rate, blood pressure) during placebo maintenance. Naltrexone and bupropion alone, or in combination, did not significantly decrease self-administration on either procedure. Low doses of bupropion (i.e., 100 mg) blunted the effects of the cocaine on subjective measures of "Like Drug" and "Stimulated". No unexpected adverse effects were observed with naltrexone and bupropion, alone and combined, in conjunction with cocaine. Together, these results do not support the use of these bupropion-naltrexone combinations for the treatment of cocaine use disorder. Future research should determine if novel drug combinations may decrease cocaine self-administration.

Health-related quality of life in patients with substance use disorders enrolled to the residential treatment in Sri Lanka: a retrospective cross-sectional study

PURPOSE

Substance use disorder (SUD) is a serious public health concern that requires continuum care with effective treatment modalities such as residential rehabilitation. Improvement in health-related quality of life (HRQoL) is one of the determinants of treatment and rehabilitation effectiveness. Therefore, a retrospective cross-sectional study was carried out in seven residential rehabilitation centres in Sri Lanka to determine the HRQoL of the rehabilitees with SUD.

METHOD

The HRQoL of 464 individuals at their enrolment and during the rehabilitation period was assessed using EuroQol five-level five-dimensional questionnaire (EQ-5D-5L). Data were analysed using IBM SPSS version 26.

RESULTS

The majority of the participants were Sinhala (n = 419, 90.3%) and Buddhist (n = 368, 79.3%) males (n = 461, 99.4%). Most were unmarried (n = 302, 65.1%), young adults (n = 385, 83.0%) who have pursued secondary or higher education (n = 276, 59.5%) and 87.3% were employed (n = 405). Most of the selected centres use biopsychosocial model (n = 4, 57.1%) as the rehabilitation approach while rest practice therapeutic community (n = 3, 42.9%). The average EQ-5D-5L index [range =( - 0.45)-1.00] of the rehabilitees at their enrolment was 0.52 ± 0.28 and the EQ-5D-5L Visual Analogue Scale (EQ-5D-5L VAS) score (range = 0-100%) was 47.17% ± 23.48%. The values were increased up to 0.83 ± 0.18 (EQ-5D-5L index) and 84.25% ± 16.79% (EQ-5D-5L VAS) during the rehabilitation period. Only 19.4% of the rehabilitees had a normal or upper normal HRQoL (≥ 0.75 EQ-5D-5L Index) at their enrolment and 72.2% of rehabilitees reported normal or upper normal HRQoL during the rehabilitation period.

CONCLUSION

A significant improvement in the HRQoL of the participants was observed during the residential treatment in comparison to the enrolment, despite the differences in the rehabilitation programs.

Evaluation of the 5-HT2C receptor drugs RO 60-0175, WAY 161503 and mirtazepine in a preclinical model of comorbidity of depression and cocaine addiction

BACKGROUND

Epidemiological data indicate a high rate of comorbidity of depression and cocaine use disorder (CUD). The role of serotonin 2C (5-HT_2C) receptors in the mechanisms responsible for the coexistence of depression and CUD was not investigated.

METHODS

We combined bilateral olfactory bulbectomy (OBX), an animal model of depression, with intravenous cocaine self-administration and extinction/reinstatement in male rats to investigate two 5-HT_2C receptor agonists (Ro 60-0175 (RO) and WAY 161503 (WAY)) and the 5-HT_2C-receptor preferring antagonist mirtazapine (MIR; an antidepressant), with the goal of determining whether these drugs alter cocaine-induced reinforcement and seeking behaviors. Additionally, neurochemical analyses were performed following cocaine self-administration and its abstinence period in the brain structures in OBX rats and SHAM-operated controls.

RESULTS

Acute administration of RO reduced, while WAY non-significantly attenuated cocaine reinforcement in both rat phenotypes. Moreover, RO or WAY protected against cocaine-seeking behavior after acute or after repeated drug administration during extinction training in OBX and SHAM rats. By contrast, acutely administered MIR did not alter cocaine reinforcement in both rat phenotypes, while it's acute (but not repeated) pretreatment reduced cocaine-seeking in OBX and SHAM rats. In neurochemical analyses, cocaine reinforcement increased 5-HT_2C receptor levels in the ventral hippocampus; a preexisting depression-like phenotype enhanced this effect. The 10-daily cocaine abstinence reduced 5-HT_2C receptor expression in the dorsolateral striatum, while the coexistence of depression and CUD enhanced local receptor expression.

CONCLUSION

The results support a key role of 5-HT_2C receptors for treating CUD and comorbid depression and CUD. They may be backs the further research of pharmacological strategies with drug targeting receptors.

Cocaine Use Disorder (CUD): Current Clinical Perspectives

Cocaine use disorder (CUD) is a devastating disorder, impacting both individuals and society. Individuals with CUD face many barriers in accessing treatment for CUD, and most individuals with CUD never receive treatment. In this review, we provide an overview of CUD, including risk factors for CUD, common co-occurring disorders, acute and chronic effects of cocaine use, and currently available pharmacological and behavioral treatments. There are no FDA-approved pharmacological treatments for CUD. Future studies with larger sample sizes and testing treatment combinations are warranted. However, individuals with CUD and co-occurring disorders (eg, a mood or anxiety disorder) may benefit from medication treatments. There are behavioral interventions that have demonstrated efficacy in treating CUD – contingency management (CM) and cognitive-behavioral therapy for substance use disorders (CBT-SUD) in particular – however many barriers remain in delivering these treatments to patients. Following the discussion of current treatments, we highlight some promising emerging treatments, as well as offer a framework that can be used in building a treatment plan for individuals with CUD.

Lifetime Dual Disorder Screening and Treatment Retention: A Pilot Cohort Study

The coexistence of a substance use disorder and another mental disorder in the same individual has been called dual disorder or dual diagnosis. This study aimed to examine the prevalence of lifetime dual disorder in individuals with alcohol or cocaine use disorder and their retention in treatment. We conducted a pilot cohort study of individuals (n = 1356) with alcohol or cocaine use disorder admitted to treatment in the public outpatient services of Barcelona (Spain) from January 2015 to August 2017 (followed-up until February 2018). Descriptive statistics, Kaplan−Meier survival curves and a multivariable Cox regression model were estimated. The lifetime prevalence of screening positive for dual disorder was 74%. At 1 year of follow-up, >75% of the cohort remained in treatment. On multivariable analysis, the factors associated with treatment dropout were a positive screening for lifetime dual disorder (HR = 1.26; 95% CI = 1.00−1.60), alcohol use (HR = 1.35; 95% CI = 1.04−1.77), polysubstance use (alcohol or cocaine and cannabis use) (HR = 1.60; 95% CI = 1.03−2.49) and living alone (HR = 1.34; 95% CI = 1.04−1.72). Lifetime dual disorder is a prevalent issue among individuals with alcohol or cocaine use disorders and could influence their dropout from treatment in public outpatient drug dependence care centres, along with alcohol use, polysubstance use and social conditions, such as living alone. We need a large-scale study with prolonged follow-up to confirm these preliminary results.

Placenta-Derived Mesenchymal-like Adherent Stromal Cells as an Effective Cell Therapy for Cocaine Addiction in a Rat Model

Recent research points to mesenchymal stem cells’ potential for treating neurological disorders, especially drug addiction. We examined the longitudinal effect of placenta-derived mesenchymal stromal-like cells (PLX-PAD) in a rat model for cocaine addiction. Sprague–Dawley male rats were trained to self-administer cocaine or saline daily until stable maintenance. Before the extinction phase, PLX-PAD cells were administered by intracerebroventricular or intranasal routes. Neurogenesis was evaluated, as was behavioral monitoring for craving. We labeled the PLX-PAD cells with gold nanoparticles and followed their longitudinal migration in the brain parallel to their infiltration of essential peripheral organs both by micro-CT and by inductively coupled plasma-optical emission spectrometry. Cell locations in the brain were confirmed by immunohistochemistry. We found that PLX-PAD cells attenuated cocaine-seeking behavior through their capacity to migrate to specific mesolimbic regions, homed on the parenchyma in the dentate gyrus of the hippocampus, and restored neurogenesis. We believe that intranasal cell therapy is a safe and effective approach to treating addiction and may offer a novel and efficient approach to rehabilitation.

Human behavioral pharmacology of stimulant drugs: An update and narrative review

Stimulant use disorders present an enduring public health concern. Chronic stimulant use is associated with a range of health problems, with notable increases in stimulant overdose that disproportionately affect marginalized populations. With these persistent problems, it is important to understand the behavioral and pharmacological factors that contribute to stimulant use in humans. The purpose of this chapter is to provide an update and narrative review on recent human laboratory research that has evaluated the behavioral pharmacology of stimulant drugs. We focus on two prototypic stimulants: cocaine as a prototype monoamine reuptake inhibitor and d-amphetamine as a prototype monoamine releaser. As such, placebo controlled human laboratory studies that involved administration of doses of cocaine or d-amphetamine and were published in peer reviewed journals within the last 10 years (i.e., since 2011) are reviewed. Primary outcomes from these studies are subjective effects, reinforcing effects, cognitive/behavioral effects, and discriminative stimulus effects. Both cocaine and d-amphetamine produce classical stimulant-like behavioral effects (e.g., increase positive subjective effects, function as reinforcers), but there are notable gaps in the literature including understanding sex differences in response to stimulant drugs, cognitive-behavioral effects of stimulants, and influence of use history (e.g., relatively drug naïve vs drug experienced) on stimulant effects.

Paternal Cocaine in Mice Alters Social Behavior and Brain Oxytocin Receptor Density in First Generation Offspring

It is well established that the damaging effects of drugs of abuse, such as cocaine, can extend beyond the user to their offspring. While most preclinical models of the generational effects of cocaine abuse have focused on maternal effects, we, and others, report distinct effects on offspring sired by fathers treated with cocaine prior to breeding. However, little is known about the effects of paternal cocaine use on first generation (F1) offspring's social behaviors. Here, we expand upon our model of oral self-administered paternal cocaine use to address the idea that paternal cocaine alters first generation offspring social behaviors through modulation of the oxytocin system. F1 cocaine-sired males displayed unaltered social recognition vs. non-cocaine sired controls but showed increased investigation times that were not related to altered olfaction. Paternal cocaine did not alter F1 male-aggression behavior or depression-like behaviors, but cocaine-sired males did display decreased anxiety-like behaviors. Female F1 behavior was similarly examined, but there were no effects of paternal cocaine. Cocaine-sired male mice also exhibited localized oxytocin receptor expression differences vs. controls in several brain regions regulating social behavior. These results provide evidence for effects of paternal cocaine exposure on social behaviors in male offspring with associated alterations in central oxytocin transmission.

Clinical neuropharmacology of cocaine reinforcement: A narrative review of human laboratory self-administration studies

Cocaine use is an unrelenting public health concern. To inform intervention and prevention efforts, it is crucial to develop an understanding of the clinical neuropharmacology of the reinforcing effects of cocaine. The purpose of this review is to evaluate and synthesize human laboratory studies that assess pharmacological manipulations of cocaine self-administration. Forty-one peer-reviewed, human cocaine self-administration studies in which participants received a pretreatment drug were assessed. The pharmacological action and treatment regimen for all drugs reviewed were considered. Drugs that increase extracellular dopamine tend to have the most consistent effects on cocaine self-administration. The ability of nondopaminergic drugs to impact cocaine reinforcement might be related to their downstream effects on dopamine, though it is difficult to draw conclusions because pharmacologically selective compounds are not widely available for human testing. The ability of acute versus chronic drug treatment to differentially affect human cocaine self-administration was not determined because buprenorphine was the only pretreatment drug that was assessed under both acute and chronic dosing regimens. Future research directly comparing acute and chronic drug treatment and/or comparing drugs with different mechanisms of action, is needed to make more conclusive determinations about the clinical neuropharmacology of cocaine reinforcement.

The Effect of Dehydroepiandrosterone Treatment on Neurogenesis, Astrogliosis and Long-Term Cocaine-Seeking Behavior in a Cocaine Self-Administration Model in Rats

Cocaine addiction is an acquired behavioral state developed in vulnerable individuals after cocaine exposure. It is characterized by compulsive drug-seeking and high vulnerability to relapse even after prolonged abstinence, associated with decreased neurogenesis in the hippocampus. This addictive state is hypothesized to be a form of “memory disease” in which the drug exploits the physiological neuroplasticity mechanisms that mediate regular learning and memory processes. Therefore, a major focus of the field has been to identify the cocaine-induced neuroadaptations occurring in the usurped brain’s reward circuit. The neurosteroid dehydroepiandrosterone (DHEA) affects brain cell morphology, differentiation, neurotransmission, and memory. It also reduces drug-seeking behavior in an animal model of cocaine self-administration. Here, we examined the long-lasting effects of DHEA treatment on the attenuation of cocaine-seeking behavior. We also examined its short- and long-term influence on hippocampal cells architecture (neurons and astrocytes). Using a behavioral examination, immunohistochemical staining, and diffusion tensor imaging, we found an immediate effect on tissue density and activation of astrocytes, which has a continuous beneficial effect on neurogenesis and tissue organization. This research emphasizes the requites concert between astrocytes and neurons in the rehabilitation from addiction behavior. Thus, DHEA may serve as a treatment that corrects brain damage following exposure to and abstinence from cocaine.

Empathy deficits and their behavioral, neuroanatomical, and functional connectivity correlates in smoked cocaine users

Reduced empathic abilities are frequently observed in drug abusers. These deficits may compromise interpersonal interactions and contribute to diminished social functioning. However, previous evidence regarding empathy and addiction is behaviorally unspecific and virtually null in terms of their brain structural or functional correlates. Moreover, no previous study has investigated how empathy is affected by drugs whose consumption is particularly characterized by counter-empathic behaviors. Here, we conducted the first assessment of neurocognitive correlates of empathy for pain in dependent users (predominantly men) of smoked cocaine (SC, coca paste, n = 37). We compared their performance in the empathy task with that of two groups matched in relevant demographic variables: 24 dependent users of insufflated cocaine hydrochloride (CC) and 21 healthy controls. In addition, we explored the structural anatomy and functional connectivity (FC) correlates of empathic impairments across groups. Our results showed that, compared to CC and controls, SC users exhibited a selective reduction of empathic concern for intentional harms. These impairments were associated with lower gray matter volumes in regions subserving social cognition (i.e., right inferior parietal lobule, supramarginal and angular gyri). Furthermore, reduced empathic concern correlated with FC within affective empathy and social cognition networks, which are also linked to cognitive changes reported in addiction (i.e., inferior frontal and orbital gyri, posterior insula, supplementary motor area, cingulate cortex). Our findings suggest that chronic consumption of SC may involve reduced empathic concern and relevant neuroanatomical and FC abnormalities, which, in turn, may result in social interaction dysfunction. These results can inform theoretical and applied developments in neuropsychopharmacology.

Psychostimulant Use Disorder, an Unmet Therapeutic Goal: Can Modafinil Narrow the Gap?

The number of individuals affected by psychostimulant use disorder (PSUD) has increased rapidly over the last few decades resulting in economic, emotional, and physical burdens on our society. Further compounding this issue is the current lack of clinically approved medications to treat this disorder. The dopamine transporter (DAT) is a common target of psychostimulant actions related to their use and dependence, and the recent availability of atypical DAT inhibitors as a potential therapeutic option has garnered popularity in this research field. Modafinil (MOD), which is approved for clinical use for the treatment of narcolepsy and sleep disorders, blocks DAT just like commonly abused psychostimulants. However, preclinical and clinical studies have shown that it lacks the addictive properties (in both behavioral and neurochemical studies) associated with other abused DAT inhibitors. Clinical availability of MOD has facilitated its off-label use for several psychiatric disorders related to alteration of brain dopamine (DA) systems, including PSUD. In this review, we highlight clinical and preclinical research on MOD and its R-enantiomer, R-MOD, as potential medications for PSUD. Given the complexity of PSUD, we have also reported the effects of MOD on psychostimulant-induced appearance of several symptoms that could intensify the severity of the disease (i.e., sleep disorders and impairment of cognitive functions), besides the potential therapeutic effects of MOD on PSUD.

Use of levamisole-adulterated cocaine is associated with increased load of white matter lesions

Background

Cocaine use has been associated with vascular pathologies, including cerebral white matter hyperintensities. Street cocaine is most often adulterated with levamisole, an anthelminthic drug that may also be associated with vascular toxicity. However, whether levamisole exposure from cocaine consumption further accelerates the development of white matter lesions remains unknown.

Methods

We investigated the association of cocaine and levamisole exposure with white matter hyperintensities in 35 chronic cocaine users and 34 healthy controls. We measured cocaine and levamisole concentrations in hair samples, which reflected exposure up to 6 months previously. We assessed the number and total surface area of the white matter hyperintensities using structural MRI (FLAIR sequence). Using generalized linear models, we analyzed the contributions of cocaine and levamisole to the number and area of white matter hyperintensities, accounting for several confounding factors.

Results

Analysis using generalized linear models revealed that cocaine users had more white matter hyperintensities in terms of total surface area, but not in terms of number. Further generalized linear models that included cocaine and levamisole hair concentrations (instead of group) as predictors indicated that levamisole exposure was strongly associated with more and larger white matter hyperintensities, suggesting that the elevated white matter hyperintensities in cocaine users were driven mainly by levamisole exposure. Finally, white matter hyperintensities in levamisole-exposed cocaine users were located primarily in the periventricular and juxtacortical white matter.

Limitations

The sample size was moderate, and blood pressure was not systematically assessed.

Conclusion

As an adulterant of cocaine, levamisole appears to increase the risk of white matter injury.

Pharmacotherapeutic strategies for treating cocaine use disorder-what do we have to offer?

BACKGROUND

Cocaine use contines to be a significant public health problem world-wide. However, despite substantial research efforts, no pharmacotherapies are approved for the treatment of cocaine use disorder (CUD).

ARGUMENT

Studies have identified positive signals for a range of medications for treating CUD. These include long-acting amphetamine formulations, modafinil, topiramate, doxazosin and combined topiramate and mixed amphetamine salts extended-release (MAS-ER). However, valid conclusions about a medication's clinical efficacy require nuanced approaches that take into account behavioural phenotypes of the target population (frequency of use, co-abuse of cocaine and other substances, genetic subgroups, psychiatric comorbidity), variables related to the medication (dose, short-/long-acting formulations, titration speed, medication adherence) and other factors that may affect treatment outcomes. Meta-analyses frequently do not account for these co-varying factors, which contributes to a somewhat nihilistic view on pharmacotherapeutic options for CUD. In addition, the predominant focus on abstinence, which is difficult for most patients to achieve, may overshadow more nuanced therapeutic signals.

CONCLUSION

While there is an emphasis on finding new medications with novel mechanisms of action for treating CUD, currently available medications deserve further investigation based on the existing literature. Evaluating refined metrics of treatment success in well-defined subgroups of patients, and further exploring combination therapies and their synergy with behavioural/psychosocial interventions, are promising avenues to establishing effective therapies for CUD.

Sexual dimorphism in pre-clinical studies of depression

Although there is a sex bias in the pathological mechanisms exhibited by brain disorders, investigation of the female brain in biomedical science has long been neglected. Use of the male model has generally been the preferred option as the female animal model exhibits both biological variability and hormonal fluctuations. Existing studies that compare behavioral and/or molecular alterations in animal models of brain diseases are generally underrepresented, and most utilize the male model. Nevertheless, in recent years there has been a trend toward the increased inclusion of females in brain studies. However, current knowledge regarding sex-based differences in depression and stress-related disorders is limited. This can be improved by reviewing preclinical studies that highlight sex differences in depression. This paper therefore presents a review of sex-based preclinical studies of depression. These shed light on the discrepancies between males and females regarding the biological mechanisms that underpin mechanistic alterations in the diseased brain. This review also highlights the conclusions drawn by preclinical studies to advance our understanding of mood disorders, encouraging researchers to promote ways of investigating and managing sexually dimorphic disorders.

Topiramate-phentermine combinations reduce cocaine self-administration in humans

RATIONALE

Cocaine use disorder is an unrelenting public health concern. Despite nearly four decades of research, an FDA approved medication is not yet available.

OBJECTIVES

The objective of this human laboratory study was to demonstrate the initial efficacy, safety and tolerability of topiramate-phentermine combinations for cocaine use disorder.

METHODS

Thirty-one (31) participants with cocaine use disorder completed this mixed-model inpatient laboratory study. Participants were maintained on topiramate (0 [N = 11], 50 [N = 9] or 100 [N = 11] mg/day). Each topiramate group was concurrently maintained on phentermine (0, 15, 30 mg). Drug self-administration, subjective responses and cardiovascular effects following acute doses of intranasal cocaine (0, 40, 80 mg) were determined during separate experimental sessions after at least seven (7) days of maintenance on each condition.

RESULTS

The three groups of participants were well matched demographically and generally did not differ significantly in their responses to a range of doses of intranasal cocaine (0, 10, 20, 40, 80 mg) during a medical safety session. Maintenance on topiramate and phentermine alone significantly decreased cocaine self-administration although these effects were modest in magnitude. Combining topiramate and phentermine robustly decreased cocaine self-administration. Topiramate and phentermine were well tolerated alone and combined, as well as in conjunction with cocaine.

CONCLUSIONS

The results of the present study support advancing topiramate-phentermine combinations as a putative pharmacotherapeutic for cocaine use disorder.

A Retrospective Comparative Study in Patients With Cocaine Use Disorder Comorbid With Attention Deficit Hyperactivity Disorder Undergoing an rTMS Protocol Treatment

Background: Adult attention-deficit/hyperactivity disorder (ADHD) is associated with high comorbidity with other psychiatric diseases, including cocaine use disorder (CocUD). Given the common fronto-striatal dysfunction, ADHD patients often use cocaine as self-medication for ameliorating symptoms by increasing striatal dopamine release. Yet, comorbidity with ADHD is related to poor treatment outcomes. CocUD has been treated with transcranial magnetic stimulation (TMS), but no studies investigated the outcomes in patients comorbid with ADHD. Methods: Twenty-two ADHD/CocUD and 208 CocUD-only participants received a high-frequency (15 Hz) rTMS treatment stimulating the left-DLPFC. We investigated whether both groups of patients shared similar demographic and clinical characteristics at baseline. Then, we monitored the effect of treatment testing for potential differences between groups. Results: At baseline demographic, toxicology and clinical features were not different between the two groups except for global severity index (GSI from SCL-90): patients of ADHD/CocUD group reported higher general symptomatology compared to the CocUD-only group. Concerning the effect of treatment, both groups significantly improved over time regarding cocaine use, craving, and other negative affect symptoms. No differences were observed between groups. Conclusions: To our knowledge, this is the first study comparing the demographic characterization and rTMS clinical improvements of patients with a dual diagnosis of ADHD and CocUD against CocUD-only patients. Cocaine use and common self-reported withdrawal/abstinence symptoms appear to benefit from rTMS treatment with no differences between groups. Future studies are needed to further investigate these preliminary results.

The orexin (hypocretin) neuropeptide system is a target for novel therapeutics to treat cocaine use disorder with alcohol coabuse

An estimated 50-90% of individuals with cocaine use disorder (CUD) also report using alcohol. Cocaine users report coabusing alcohol to 'self-medicate' against the negative emotional side effects of the cocaine 'crash', including the onset of anxiety. Thus, pharmaceutical strategies to treat CUD would ideally reduce the motivational properties of cocaine, alcohol, and their combination, as well as reduce the onset of anxiety during drug withdrawal. The hypothalamic orexin (hypocretin) neuropeptide system offers a promising target, as orexin neurons are critically involved in activating behavioral and physiological states to respond to both positive and negative motivators. Here, we seek to describe studies demonstrating efficacy of orexin receptor antagonists in reducing cocaine, alcohol- and stress-related behaviors, but note that these studies have largely focused on each of these phenomena in isolation. For orexin-based compounds to be viable in the clinical setting, we argue that it is imperative that their efficacy be tested in animal models that account for polysubstance use patterns. To begin to examine this, we present new data showing that rats' preferred level of cocaine intake is significantly increased following chronic homecage access to alcohol. We also report that cocaine intake and motivation are reduced by a selective orexin-1 receptor antagonist when rats have a history of cocaine + alcohol, but not a limited history of cocaine alone. In light of these proof-of-principle data, we outline what we believe to be the key priorities going forward with respect to further examining the orexin system in models of polysubstance use. This article is part of the special issue on Neurocircuitry Modulating Drug and Alcohol Abuse.

A Rat Model of Cocaine-Alcohol Polysubstance Use Reveals Altered Cocaine Seeking and Glutamate Levels in the Nucleus Accumbens

Preclinical models of cocaine use disorder are widely utilized to identify neuroadaptations underlying cocaine seeking and to screen medications to reduce seeking. However, while the majority of cocaine users engage in poly-substance use (PSU), a minority of preclinical studies employ PSU models. We previously reported that when rats consume alcohol after daily intravenous cocaine self-administration, nucleus accumbens (NA) core basal glutamate levels are reduced below those of rats that consumed only cocaine, and do not increase during cue + cocaine-primed reinstatement of cocaine-seeking. Here we used the same model of sequential cocaine and alcohol self-administration to test the hypothesis that a similar pattern of glutamate changes would be observed in the NA core prior to and during a cocaine-primed reinstatement test. Rats underwent intravenous cocaine self-administration followed by access to unsweetened alcohol in the home cage for 12 days. Rats underwent a minimum of 12 daily extinction sessions prior to a cocaine-primed reinstatement test conducted during microdialysis procedures. Contrary to our previous work using the same model, here we found that access to alcohol increased cocaine intake and increased responding during early extinction training. We found that as in our previous work, cocaine + alcohol-consuming rats displayed basal glutamate levels below those of rats that self-administered only cocaine. During the cocaine-primed reinstatement test, rats that consumed only cocaine displayed increased glutamate efflux in the NA core while those that consumed cocaine + alcohol did not. These results indicate that preclinical models of PSU should be utilized to develop experimental therapeutics for the reduction of cocaine seeking.

Prescription psychostimulants for the treatment of stimulant use disorder: a systematic review and meta-analysis

RATIONALE

Agonist-based pharmacologic intervention is an accepted approach in treatment of opioid and tobacco use disorders.

OBJECTIVES

We conducted a systematic review and meta-analysis to evaluate usefulness of an agonist approach as treatment of (psycho)stimulant use disorder (PSUD).

METHODS

We reviewed PubMed/Medline, LILACS, and ClinicalTrials.gov databases searching for randomized, double-blind, placebo-controlled, parallel-design studies evaluating outcomes of individuals treated for cocaine- or amphetamine-type substance use disorder. We combined results of all trials that included the following prescription psychostimulants (PPs): modafinil, methylphenidate, or amphetamines (mixed amphetamine salts, lisdexamphetamine, and dextroamphetamine). The combined sample consisted of 2889 patients. Outcomes of interest included the following: drug abstinence (defined as 2-3 weeks of sustained abstinence and the average maximum days of consecutive abstinence), percentage of drug-negative urine tests across trial, and retention in treatment. We conducted random-effects meta-analyses and assessed quality of evidence using the GRADE system.

RESULTS

Thirty-eight trials were included. Treatment with PPs increases rates of sustained abstinence [risk ratio (RR) = 1.45, 95% confidence interval (CI) = (1.10, 1.92)] and duration of abstinence [mean difference (MD) = 3.34, 95% CI = (1.06, 5.62)] in patients with PSUD, particularly those with cocaine use disorder (very low-quality evidence). Prescription amphetamines were particularly efficacious in promoting sustained abstinence in patients with cocaine use disorder [RR = 2.44, 95% CI = (1.66, 3.58)], and higher doses of PPs were particularly efficacious for treatment of cocaine use disorder [RR = 1.95, 95% CI = (1.38, 2.77)] (moderate-quality evidence). Treatment with prescription amphetamines also yielded more cocaine-negative urines [MD = 8.37%, 95% CI = (3.75, 12.98)]. There was no effect of PPs on the retention in treatment.

CONCLUSION

Prescription psychostimulants, particularly prescription amphetamines given in robust doses, have a clinically significant beneficial effect to promote abstinence in the treatment of individuals with PSUD, specifically the population with cocaine use disorder.

Prevalence of comorbid substance use in major depressive disorder in community and clinical settings, 1990-2019: Systematic review and meta-analysis

BACKGROUND

Comorbidity between Substance Use Disorders (SUDs) and major depression is highly prevalent. This systematic review and meta-analysis aimed to estimate the prevalence of SUDs in subjects diagnosed with a major depressive disorder (MDD) in community, inpatient and outpatient settings.

METHODS

A comprehensive literature search of Medline, EMBASE, PsycINFO and CINAHL databases was conducted from 1990 to 2019. Prevalence of co-morbid SUDs and MDD were extracted and odds ratios (ORs) were calculated using random effects meta-analysis.

RESULTS

There were 48 articles identified by electronic searches with a total sample size of 348,550 subjects that yielded 14 unique epidemiological studies, 2 national case registry studies, 7 large cohort studies and 20 clinical studies using in- or out-patients. The prevalence of any SUD in individuals with MDD was 0.250. Maximum prevalence was found with alcohol use disorder (0.208), followed by illicit drug use disorder (0.118) and cannabis use disorder (0.117). Meta-analysis showed the pooled variance of any AUD in men with MDD was 36%, which was significantly higher than that for females with MDD (19%, OR 2.628 95% CI 2.502, 2.760).

CONCLUSIONS

Few studies were published over the last decade so current prevalence rates of SUD in MDD are needed. Meta-analysis revealed that SUDs in MDD are highly prevalent and rates have not changed over time. The persistently high prevalence suggests there is an urgent need for more informative studies to help develop better prevention and treatment options for reducing prevalence of SUDs in persons with major depression and co-morbid disorders.

Sensitivity to gains during risky decision-making differentiates chronic cocaine users from stimulant-naïve controls

BACKGROUND

Chronic cocaine use has been consistently associated with decision-making impairments that contribute to the development and maintenance of drug-taking. However, the underlying cognitive processes of risk-seeking behaviours observed in chronic cocaine users (CU) have so far remained unclear. Here we therefore tested whether CU differ from stimulant-naïve controls in their sensitivity to gain, loss, and probability of loss information when making decisions under risk.

METHOD

A sample of 96 participants (56 CU and 40 controls) performed the no-feedback version of the Columbia Card Task, designed to assess risk-taking in relation to gain, loss, and probability of loss information. Additionally, cognitive performance and impulsivity were determined. Current and recent substance use was objectively assessed by toxicological urine and hair analysis.

RESULTS

Compared to controls, CU showed increased risk-seeking in unfavourable decision scenarios in which the loss probability was high and the returns were low, and a tendency for increased risk aversion in more favourable decision scenarios. In comparison to controls, CU were less sensitive to gain, but similarly sensitive to loss and probability of loss information. Further analysis revealed that individual differences in sensitivity to loss and probability of loss information were related to cognitive performance and impulsivity.

CONCLUSION

Reduced sensitivity to gains in people with CU may contribute to their propensity for making risky decisions. While these alterations in gain sensitivity might directly relate to cocaine use per se, the individual psychopathological profile of CU might moderate sensitivity to loss information.

Psychiatric symptoms and expression of glucocorticoid receptor gene in cocaine users: A longitudinal study

BACKGROUND

Chronic cocaine users (CU) display reduced peripheral expression of the glucocorticoid receptor gene (NR3C1), which is potentially involved in stress-related psychiatric symptoms frequently occurring in CU. However, it is unknown whether psychiatric symptoms and lower NR3C1 expression are related to each other and whether reduction of drug consumption reverse them.

METHOD

At baseline, NR3C1 mRNA expression was measured in 68 recreational CU, 30 dependent CU, and 68 stimulant-naïve controls. Additionally, the Revised Symptom Checklist (SCL-90R) and the Barratt Impulsiveness Scale (BIS) were assessed. At a one-year follow-up, the association between change in NR3C1 expression and psychiatric symptoms was examined in 48 stimulant-naïve controls, 19 CU who increased and 19 CU who decreased their consumption. At both test sessions, cocaine concentrations in hair samples were determined. Mixed-effects models were used to investigate how changes in drug use intensity affect severity of psychiatric symptoms and NR3C1 expression over time.

RESULTS

At baseline, recreational and dependent CU displayed elevated impulsivity and considerable symptom burden across most of the SCL-90R subscales. Time-group interaction effects were found for several impulsivity scores, SCL-90R Global Severity Index, Paranoid Thoughts, and Depression subscales as well as for NR3C1 expression. Pairwise comparisons showed that decreasing CU specifically improved in these SCL-90R subscales, while their NR3C1 expression was adapted. Finally, changes in NR3C1 expression were negatively correlated with changes in impulsivity but not SCL-90R scores.

CONCLUSION

Our findings suggest that NR3C1 expression changes and some psychiatric symptoms are reversible upon reduction of cocaine intake, thus favouring abstinence-oriented treatment approaches.

Sequential cocaine-alcohol self-administration produces adaptations in rat nucleus accumbens core glutamate homeostasis that are distinct from those produced by cocaine self-administration alone

There are currently no FDA-approved medications to reduce cocaine relapse. The majority of preclinical studies aimed at identifying the neurobiology underlying relapse involve the self-administration of cocaine alone, whereas many, if not a majority, of cocaine users engage in polysubstance use. Here we developed a rat model of sequential cocaine and alcohol self-administration to test the hypothesis that this combination produces distinct neuroadaptations relative to those produced by cocaine alone. Male rats underwent intravenous cocaine self-administration (2 h/day) followed by 6 h access to unsweetened alcohol (20% v/v) for 12 days. After extinction training, we assessed surface expression of the glutamate transporter GLT-1 and glutamate efflux in the nucleus accumbens (NA) core during the reinstatement of cocaine-seeking. We also tested the ability of ceftriaxone to attenuate the reinstatement of cocaine-seeking and assessed reinstatement-induced Fos expression in several regions critical for reinstatement. Alcohol consumption did not alter cocaine intake, nor did access to cocaine alter alcohol consumption. However, we noted significant changes in glutamate homeostasis in the NA core of cocaine + alcohol rats relative to rats consuming cocaine alone, such as increased surface GLT-1 expression and a lack of increase in glutamate efflux during reinstatement of cocaine-seeking. A history of cocaine + alcohol also altered patterns of reinstatement-induced Fos expression. These changes likely account for the inability of ceftriaxone to attenuate cocaine relapse in cocaine + alcohol rats, while it does so in rats consuming only cocaine. As such glutamate neuroadaptations are targeted by medications to reduce cocaine relapse, preclinical models should consider polysubstance use.

Attention Deficit Hyperactivity Disorder in Prisoners: Increased Substance Use Disorder Severity and Psychiatric Comorbidity

OBJECTIVES

Attention deficit hyperactivity disorder (ADHD) and substance use disorders (SUD) are overrepresented among incarcerated populations. We examined whether ADHD was associated with increased severity of comorbid SUD and with increased psychiatric comorbidity among prisoners.

METHODS

Cross-sectional study of 500 randomly selected Latino male prisoners in the Puerto Rico Correctional System using validated diagnostic measures to assess Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) ADHD and SUD diagnosis, antisocial personality disorder (ASP) and borderline personality disorder (BPD), major depression, and generalized anxiety disorder (GAD). We defined SUD severity by symptom count and by presence of at least 2 current SUD diagnoses (polysubstance).

RESULTS

Participants with ADHD had increased risk for lifetime (p < 0.05) and current (p < 0.01) SUDs, all comorbid psychiatric disorders, and suicidality (p < 0.001). They had more severe SUD, both in number of symptoms and number of SUD (polysubstance) diagnoses (p < 0.01). ADHD was associated with increased psychiatric comorbidity, as participants with ADHD were more likely to have a second diagnosis, and a greater number of comorbid disorders (p < 0.001). ASP, BPD, major depression, and GAD, but not ADHD, were significant predictors of SUD severity in adjusted models.

CONCLUSIONS

Findings highlight the complex mental health needs of incarcerated populations, where SUD, ADHD, and other psychiatric disorders are prevalent and interrelated.

Impact of Sex and ADHD Status on Psychiatric Comorbidity in Treatment-Seeking Alcoholics

Objective: To assess for intrasex and intersex differences in psychiatric comorbidity according to ADHD status in treatment-seeking adults with alcohol use disorders (AUDs). Method: This study was a secondary analysis of data utilizing descriptive statistics from 472 treatment-seeking alcoholics who completed the Psychiatric Research Interview for Substance and Mental Disorders (PRISM). Results: The prevalence of ADHD in males and females was 6.0% and 6.4%, respectively. Males with ADHD and AUDs had higher rates of current and lifetime drug use disorders, current depressive disorders, and current and lifetime anxiety disorders than male alcoholics without ADHD. No intrasex differences in psychiatric comorbidities were identified in female alcoholics with respect to ADHD status. Males with ADHD and AUDs were more likely to have had opioid dependence than ADHD-positive females. No other intersex differences were found. Conclusion: Positive ADHD status was associated with increased psychiatric comorbidity among treatment-seeking alcoholic men.

Influence of phendimetrazine maintenance on the reinforcing, subjective, performance, and physiological effects of intranasal cocaine

RATIONALE

No pharmacotherapies are approved for cocaine use disorder. Phendimetrazine, a prodrug of the monoamine-releaser phenmetrazine, attenuates the reinforcing effects of cocaine in preclinical models, has minimal abuse potential, and is safe when combined with cocaine.

OBJECTIVES

This study determined the influence of phendimetrazine maintenance on the reinforcing effects of cocaine (i.e., choice to self-administer cocaine), along with the subjective, performance, and physiological effects of cocaine. We hypothesized that phendimetrazine would attenuate the reinforcing effects of cocaine.

METHODS

Twenty-nine subjects with cocaine use disorder completed this within-subject, inpatient study. The subjects were maintained on placebo and 210 mg phendimetrazine in a counterbalanced order. After at least 7 days of maintenance on the target dose, the subjects completed experimental sessions in which the effects of single doses of 0, 20, 40, and 80 mg of intranasal cocaine were determined.

RESULTS

Cocaine functioned as a reinforcer, producing significant dose-related increases in self-administration. Cocaine increased prototypic effects (e.g., ratings of stimulated and blood pressure). Phendimetrazine attenuated ratings on a select set of subjective outcomes (e.g., ratings of talkative/friendly), but failed to reduce the reinforcing effects of cocaine or a majority of positive subjective cocaine effects. Phendimetrazine increased heart rate, indicating a physiologically active dose was tested, but heart rate increases were not clinically significant.

CONCLUSIONS

These results indicate that although phendimetrazine can safely be combined with cocaine, it does not attenuate the abuse-related effects of cocaine. It is unlikely, then, that phendimetrazine will be an effective standalone treatment for cocaine use disorder.

Glucocorticoid receptor gene variants and lower expression of NR3C1 are associated with cocaine use

Animal and cross-sectional human studies suggest that chronic cocaine use is associated with altered responsivity of the hypothalamic-pituitary-adrenal axis to stress. Moreover, increased susceptibility to stress has been proposed as an important factor for development, maintenance and relapse of cocaine addiction. As the glucocorticoid receptor gene (NR3C1) mediates genomic effects of the stress hormone cortisol, we investigated NR3C1 expression and the association of NR3C1 genotypes with cocaine use, addiction and comorbid psychiatric symptoms in 126 chronic cocaine users and 98 stimulant-naïve healthy controls. A comprehensive psychiatric assessment was performed including severity of depressive symptoms and current psychological distress. Whole blood NR3C1 mRNA levels were determined and six NR3C1 polymorphisms (rs10482605, rs41423247, rs10052957, rs6189, rs56149945 and rs6198) were genotyped. Compared to controls, cocaine users showed significantly lower NR3C1 expression (P < 0.001), which was not affected by NR3C1 genotypes. In controls, rs41423247 [P < 0.01, false discovery rate (FDR)-corrected], haplotype 2 and haplotype 3 (both P < 0.05, FDR-corrected) were associated with altered NR3C1 gene expression. Haplotype 3 (including minor alleles of rs10052957 and rs41423247) was associated with an increased risk for cocaine addiction (odds ratio = 2.74, P < 0.05, uncorrected). Moreover, addicted cocaine users carrying haplotype 3 showed higher depression scores (P < 0.01, FDR-corrected) than noncarriers. Considering possible confounding effects of alcohol and/or depression, we conclude that chronic cocaine use is associated with lower NR3C1 gene expression suggesting possible direct effects of the drug on the biological adaptation of stress-related genes. Finally, we postulate that haplotype 3 of NR3C1 might serve as a potential risk factor for stimulant addiction and associated psychiatric symptoms.

Rostrocaudal subregions of the ventral tegmental area are differentially impacted by chronic stress

RATIONALE

The ventral tegmental area (VTA) is implicated in the pathophysiology of depression and addictive disorders and is subject to the detrimental effects of stress. Chronic stress may differentially alter the activity pattern of its different subregions along the rostrocaudal and dorsoventral axes, which may relate to the variable behavioral sensitivity to stress mediated by these subregions.

OBJECTIVES

Here, chronic stress-exposed rats were tested for depressive-like reactivity. In situ hybridization for zif268 as a marker of neuronal activation was combined with in vivo single-unit recording of dopaminergic neurons to assess modifications in the activity of the rostral VTA (rVTA) and caudal VTA (cVTA). Changes in the expression of stress-responsive glucocorticoid receptors (GR) and brain-derived neurotrophic factor (BDNF) were also assessed.

RESULTS

Stress-induced anhedonia-like, hyper-anxious, and passive-like responding were associated with reductions in dopaminergic burst activity in the cVTA and an increase in local GABAergic activity, particularly in GABA_A receptor sensitivity. On the other hand, stress increased single-spiking activity, burst activity, and zif268 mRNA levels in the rVTA, which were associated with increased glutamatergic tonus and enhanced GR and AMPA receptor (AMPAR) expression. rVTA and cVTA activity differentially correlated with sucrose preference and passivity measures.

CONCLUSIONS

These data demonstrate that the rVTA and cVTA respond differently to stress and suggest that while cVTA activity may be related to passivity-like states, the activity of both subregions appears to be related to anhedonia and the processing of incentive value. These region-dependent abnormalities indicate the multi-modular composition of the VTA, which could provide multiple substrates for different symptom features.

Comorbidity of DSM–III–R Major Depressive Disorder in the General Population: Results from the US National Comorbidity Survey

General population data are presented on the prevalence and correlates of comorbidity between DSM–III–R major depressive disorder (MDD) and other DSM–III–R disorders. The data come from the US National Comorbidity Survey, a large general population survey of persons aged 15–54 years in the non-institutionalised civilian population. Diagnoses are based on a modified version of the Composite International Diagnostic Interview (CIDI). The analysis shows that most cases of lifetime MDD are secondary, in the sense that they occur in people with a prior history of another DSM–III–R disorder. Anxiety disorders are the most common primary disorders. The time-lagged effects of most primary disorders on the risk of subsequent MDD continue for many years without change in magnitude. Secondary MDD is, in general, more persistent and severe than pure or primary MDD. This has special public health significance because lifetime prevalence of secondary MDD has increased in recent cohorts, while the prevalence of pure and primary depression has remained unchanged.

What does the Fos say? Using Fos-based approaches to understand the contribution of stress to substance use disorders

Despite extensive research efforts, drug addiction persists as a largely unmet medical need. Perhaps the biggest challenge for treating addiction is the high rate of recidivism. While many factors can promote relapse in abstinent drug users, the contribution of stress is particularly problematic, as stress is uncontrollable and pervasive in the lives of those struggling with addiction. Thus, understanding the neurocircuitry that underlies the influence of stress on drug seeking is critical for guiding treatment. Preclinical research aimed at defining this neurocircuitry has, in part, relied upon the use of experimental approaches that allow visualization of cellular and circuit activity that corresponds to stressor-induced drug seeking in rodent relapse models. Much of what we have learned about the mechanisms that mediate stressor-induced relapse has been informed by studies that have used the expression of the immediate early gene, cfos, or its protein product, Fos, as post-mortem activity markers. In this review we provide an overview of the rodent models used to study stressor-induced relapse and briefly summarize what is known about the underlying neurocircuitry before describing the use of cfos/Fos-based approaches. In addition to reviewing findings obtained using this approach, its advantages and limitations are considered. Moreover, new techniques that leverage the expression profile of cfos to tag and manipulate cells based on their activity patterns are discussed. The intent of the review is to guide the interpretation of old and design of new studies that utilize cfos/Fos-based strategies to study the neurocircuitry that contributes to stress-related drug use.

Differences in mortality in a cohort of cocaine use disorder patients with concurrent alcohol or opiates disorder

AIMS

To study mortality in a cohort of cocaine use disorder patients, and compare results in those with concurrent alcohol or opiates disorder.

DESIGN, SETTING AND PARTICIPANTS

A cohort of 10 539 cocaine use disorder individuals entering drug treatment in public out-patient centres in the city of Barcelona was followed from 1997 to 2011. Participants were divided at baseline into three groups: those with only cocaine use disorder (CUD), those with cocaine and alcohol use disorder but not opioid (CAUD) and those with cocaine and opioid use disorder (COUD). Mortality was assessed through the Spanish National Mortality Register.

MEASUREMENTS

Crude mortality rates (CMR), standardized mortality ratios (SMR) and rate ratios (RR) were calculated for each group. A multivariable Cox regression model was fitted to obtain adjusted mortality hazard ratios (aHR) of CAUD and COUD with respect to CUD. Specific mortality causes were also examined.

FINDINGS

The total of 716 deaths registered resulted in a CMR = 6.0/1000 person-years (PY); 95% confidence interval (CI) = 5.1-7.0 for CUD, CMR = 5.8/1000 PY (95% CI = 4.9-6.7) for CAUD and CMR = 20.7/1000 PY (95% CI = 18.8-22.8) for COUD, with no significant differences among sexes. Compared with the general population, mortality was four times higher (SMR = 4.1, 95% CI = 3.5-4.8) among CUD, more than three times among CAUD (SMR = 3.4, 95% CI = 2.9-3.9) and more than 10 times among COUD (SMR = 11.6, 95% CI = 10.5-12.8), being always higher in women. External injuries, led by overdose, accumulated the biggest percentage of deaths among the three groups, but infectious diseases showed the highest excess mortality. Some differences regarding causes of death were observed between the three groups.

CONCLUSIONS

Mortality risk and excess mortality are significantly greater among those with cocaine and opiates use disorder than among people with only cocaine use disorder or cocaine and alcohol use disorder.

Sex differences in daily life stress and craving in opioid-dependent patients

BACKGROUND

Responses to stress and drug craving differ between men and women. Differences in the momentary experience of stress in relation to craving are less well-understood.

OBJECTIVES

Using ecological momentary assessment (EMA), we examined sex differences in real-time in two areas: (1) causes and contexts associated with stress, and (2) the extent to which stress and drug cues are associated with craving.

METHODS

Outpatients on opioid-agonist treatment (135 males, 47 females) reported stress, craving, and behavior on smartphones for 16 weeks. They initiated an entry each time they felt more stressed than usual (stress event) and made randomly prompted entries 3 times/day. In stress-event entries, they identified the causes and context (location, activity, companions), and rated stress and craving severity.

RESULTS

The causes reported for stress events did not differ significantly by sex. Women reported arguing and being in a store more often during stress events, and men reported working more often during stress events, compared to base rates (assessed via random prompts). Women showed a greater increase in opioid craving as a function of stress (p < 0.0001) and had higher stress ratings in the presence of both stress and drug cues relative to men (p < 0.01). Similar effects were found for cocaine craving in men (p < 0.0001).

CONCLUSION

EMA methods provide evidence based on real-time activities and moods that opioid-dependent men and women experience similar contexts and causes for stress but differ in stress- and cue-induced craving. These findings support sex-based tailoring of treatment, but because not all participants conformed to the overall pattern of sex differences, any such tailoring should also consider person-level differences.

Memory-Focused Cognitive Therapy for Cocaine Use Disorder: Theory, Procedures and Preliminary Evidence From an External Pilot Randomised Controlled Trial

BACKGROUND

Cocaine use disorder (CUD) is a debilitating condition with no NICE-recommended medication or specific psychosocial interventions. In the United Kingdom (UK), general counselling (treatment-as-usual; TAU) is widely delivered, but has limited effectiveness. We tested the feasibility, safety and preliminary efficacy of a novel, adjunctive psychosocial intervention for CUD, called 'memory-focused cognitive therapy' (MFCT).

METHODS

We did a two-arm, external pilot randomised controlled trial at a specialist community National Health Service addictions clinic in London, UK. 30 adults (≥18years), voluntarily seeking treatment for CUD (enrolled ≥14days; all with moderate-to-severe DSM5 CUD), were individually randomised (1:1) to a control group (ongoing TAU; 3×90min CUD cognitive conceptualisation assessments; 2×30min cocaine-related cue-induction procedures; and 3×30min research follow-ups); or to an intervention group (ongoing TAU; 3×90min cognitive conceptualisation assessments; 2×30min cocaine-related cue-induction procedures; 5×120min, one-to-one, MFCT sessions [in 1week]; and 3×60min research follow-ups and MFCT-relapse prevention). The primary outcome was the total percentage score on the frequency version of the Craving Experiences Questionnaire (CEQ-F) at 1-month follow-up after the intensive intervention week (clinical endpoint; recall period past 2weeks; higher score indicating greater craving). Secondary outcomes at the 1-month follow-up were percentage days abstinent (PDA) from cocaine, and longest period (days) of continuous abstinence (LPA) in the prior 28days. Outcomes were analysed as an unadjusted group mean difference (with Hedge's g effect size [ES]) and a 95% Confidence Interval [CI] for the primary outcome and a 90% CI for the secondary outcomes. Exploratory, multivariable linear (primary outcome) and Poisson regression models (secondary outcomes), with sex, age, months of regular cocaine use, baseline outcome score, and group estimated the effectiveness of the intervention. The trial is registered with the ISCRTN (ISRCTN16462783).

FINDINGS

Between July 15, 2015, and November 27, 2016, 58 patients were assessed for eligibility and 30 participants were randomised (14 to the control group and 16 to the intervention). With outcome data collected for all participants at the endpoint, the intervention group mean CEQ-F score (14·77; SD 21·47) was lower than the control group mean (51·75; SD 22·72); ES -1·62; 95% CI -2·45 to -0·80. MFCT was associated with more cocaine abstinence in the intervention group (PDA 85·94; SD 18·96) than the control group (PDA 54·59; SD 30·29); ES 1·19; 90% CI 0·54 to 1·84. There was also greater maximum abstinence in the intervention group (LPA 15·69; SD 10·10) than the control group (6·00; SD 7·36); ES 1·06; 90% CI 0·41 to 1·70. Exploratory, confounder-adjusted regression models for this preliminary effect supported the treatment association for reduced craving experiences (CEQ-F Coef. -28·25; 95% CI -45·15 to -11·35); more abstinence (PDA Incidence Rate Ratio [IRR] 1·56; 95% CI 1·31 to 1·88); and greater maximum abstinence (LPA IRR 2·56; 95% CI 1·96 to 3·35), although relative weak unmeasured confounding could overturn these model-adjusted exposure-outcome associations. There were four serious adverse events (among three participants). None were judged related to study procedures or interventions.

INTERPRETATION

In this first external pilot randomised controlled trial of MFCT for CUD, we have shown that the intervention and control procedures and acceptable feasible and safe, and report preliminary evidence that MFCT is associated with reduced craving and increased abstinence. These findings support progression to a substantive trial.

FUNDING SOURCE

UK National Institute for Health Research, Biomedical Research Centre.

Predictors of heroin abstinence in opiate substitution therapy in heroin-only users and dual users of heroin and crack

AIMS

To analyse predictors of heroin abstinence in opiate substitution therapy (OST) based on frequency of crack use and its interactions with other predictors in a clinical non-experimental setting.

DESIGN

Retrospective study.

SETTING

A community drug service in London, UK.

PARTICIPANTS

325 clients starting OST between 2010 and 2014 (197 methadone and 128 buprenorphine).

MEASUREMENTS

Logistic regression models (a general model and separate models for methadone and buprenorphine) assessed demographic and clinical data as predictors of heroin abstinence at one year after treatment start (or at the date of transfer to another service).

FINDINGS

For the general model participants choosing methadone were more likely to use heroin at follow up (OR=2.36, 95% CI: 1.40-3.17) as were daily crack users on methadone (OR=2.62, 95% CI: 0.96-7.16). For the methadone model only daily crack use predicted heroin use at follow up (OR=2.62, 95% CI: 0.96-7.16). For buprenorphine, higher amounts of baseline heroin use, lower buprenorphine dose and daily drinking predicted heroin use at follow up (OR=0.85, 95% CI: 0.75-0.95; OR=1.31, 95% CI: 1.06-1.60 and OR=6.04, 95% CI: 1.26-28.92). Both use of cannabis and depression increased likelihood of heroin abstinence for clients not using crack compared to occasional (OR=6.68, 95% CI: 0.37-119.59; OR=106.31, 95% CI: 3.41-3313.30) and daily (OR=57.49 (95% CI: 2.37-1396.46; OR=170.99 (95% CI: 4.61-6339.47) users.

CONCLUSIONS

Most of the predictors in the general model were found significant only in the buprenorphine but not in the methadone model, suggesting that a general model has little predictive value. Crack use was a significant predictor of heroin abstinence at follow up in all models, however for buprenorphine only when depression or cannabis use was present. Further research is needed to assess effective treatment approaches for the growing population of dual users.

Cognitive behavioral interventions for alcohol and drug use disorders: Through the stage model and back again

Cognitive-behavioral therapy (CBT) approaches have among the highest level of empirical support for the treatment of drug and alcohol use disorders. As Psychology of Addictive Behaviors marks its 30th anniversary, we review the evolution of CBT for the addictions through the lens of the Stage Model of Behavioral Therapies Development. The large evidence base from Stage II randomized clinical trials indicates a modest effect size with evidence of relatively durable effects, but limited diffusion in clinical practice, as is the case for most empirically validated approaches for mental health and addictive disorders. Technology may provide a means for CBT interventions to circumvent the "implementation cliff" in Stages III-V by offering a flexible, low-cost, standardized means of disseminating CBT in a range of novel settings and populations. Moreover, returning to Stage I to reconnect clinical applications of CBT to recent developments in cognitive science and neuroscience holds great promise for accelerating understanding of mechanisms of action. It is critical that CBT not be considered as a static intervention, but rather 1 that constantly evolves and is refined through the stage model until the field achieves a maximally powerful intervention that addresses core features of the addictions. (PsycINFO Database Record

Contingency management targeting abstinence is effective in reducing depressive and anxiety symptoms among crack cocaine-dependent individuals

Although contingency management (CM) is effective in promoting abstinence and treatment retention among crack cocaine users who meet the criteria for cocaine dependence, less is known about its off-target effects. In this secondary analysis, we evaluated the impact of CM on depressive and anxiety symptoms in a sample of cocaine-dependent individuals under treatment. Sixty-five crack cocaine users who met the criteria for cocaine dependence were randomly assigned to receive 12 weeks of standard treatment alone (STA; n = 32) or 12 weeks of standard treatment plus CM (STCM; n = 33). The outcome measures of the secondary analysis were depressive and anxiety symptoms assessed with the Beck Depression Inventory-II (BDI-II) and the Beck Anxiety Inventory (BAI). At baseline, 59 (90.8%) of the participants reported at least mild depressive symptoms and 47 (72.5%) reported at least mild anxiety symptoms. The mean BDI-II (24.5 ± 12.1) and BAI (20.7 ± 13.5) scores in the sample as a whole was moderate. After treatment, the reported levels of depressive symptoms (β = -9.6, p < .05) and anxiety symptoms (β = -9.9, p < .05) were lower among the individuals receiving STCM than among those receiving STA. This study provides evidence that an STCM intervention targeting crack cocaine abstinence also produces significant reductions in depressive and anxiety symptoms. This low cost intervention also demonstrated significant promise and optimization potential for crack cocaine users in a setting of scarce resources and high mental health comorbidity. Relevance Statement: We found that the prevalence of depressive and anxiety symptoms were extremely high among crack cocaine users, and that, among such individuals, contingency management (CM) reduced depressive and anxiety symptomatology to a greater degree than did standard treatment. Our results suggest that CM targeting crack cocaine abuse can have off-target effects on psychiatric symptomatology. (PsycINFO Database Record

Sex differences in guanfacine effects on stress-induced stroop performance in cocaine dependence

AIMS

Chronic drug abuse leads to sex-specific changes in drug cue and stress physiologic and neuroendocrine reactivity as well as in neural responses to stress and cue-related challenges and in executive function such as inhibitory control, cognitive flexibility and self control. Importantly, these functions have been associated with high risk of relapse and treatment. Alpha-2 agonism may enhance inhibitory cognitive processes in the face of stress with sex-specific effects, however this has not been previously assessed in cocaine dependence.

METHOD

Forty inpatient treatment-seeking cocaine dependent individuals (13F/27M) were randomly assigned to receive either placebo or up to 3mgs of Guanfacine. Three laboratory sessions were conducted following 3-4 weeks of abstinence, where patients were exposed to three 10-min personalized guided imagery conditions (stress, drug cue, combined stress/cue), one per day, on consecutive days in a random, counterbalanced order. The Stroop task was administered at baseline and immediately following imagery exposure.

RESULTS

Guanfacine treated women improved their performance on the Stroop task following exposure to all 3 imagery conditions compared with placebo women (p=0.02). This improvement in cognitive inhibitory performance was not observed in the men.

CONCLUSIONS

Enhancing the ability to cognitively regulate in the face of stress, drug cues and combined stress and drug cue reactivity may be key targets for medications development in cocaine dependent women.

Do addicts have free will? An empirical approach to a vexing question

INTRODUCTION

This paper addresses two overlapping questions: Do addicts have the capacity to voluntarily quit drugs? And do individuals knowingly pursue courses of action that they realize are bad for them, such as excessive drug use?

METHODS

I propose two testable versions of free will. First, the observation that activities differ in the degree to which they are susceptible to the influence of their consequences (e.g., costs and benefits) has proven a useful criterion for classifying behavior as voluntary or involuntary. Thus, we can ask if drug use in addicts is influenced by its consequences. For instance, do laws that promise legal sanctions for drug use reduce drug use in addicts? Second, the philosopher Harry Frankfurt proposed a definition of free will that takes into account desires and self-reflection. I propose that addicts who do not want to desire drugs and successfully stop craving drugs pass his test.

RESULTS

Dependence on illicit drugs typically ends after about four to six years. Dependence on cigarettes and alcohol persists for much longer, but most smokers and alcoholics eventually voluntarily quit using. Smokers and heroin addicts can voluntarily regulate their drug cravings as a function of the availability of their drug of choice. They have the capacity to pass Frankfurt's test of free will.

CONCLUSIONS

Addicts have free will as defined by the capacity to voluntary quit using drugs and to voluntarily regulate their cravings.

Treatment of Cannabis Use Disorder: Current Science and Future Outlook

Cannabis is the most commonly used illicit substance in the United States. Rates of cannabis use and cannabis use disorder (CUD) have increased in the past decade, paralleling changes in the legal and political climate favoring legalization. Almost 20 million people 12 years or older report past-month cannabis use, and 8 million report daily or near-daily use. Concurrently, the perception that cannabis use poses a significant risk of negative consequences has decreased. Contrary to this perception, heavy cannabis use is associated with cognitive impairment, increased risk for psychotic disorders and other mental health problems, lower education attainment, and unemployment. Clinical trials of various treatments for CUD have likewise increased, focusing primarily on psychotherapy treatments, specifically motivational enhancement therapy, cognitive behavioral therapy, and contingency management. Their findings suggest that a combination of these three modalities produces the best abstinence outcomes, although abstinence rates remain modest and decline after treatment. More recently, pharmacotherapy trials have been conducted as adjunctive interventions to psychosocial treatment. N-acetylcysteine and gabapentin are two of the most promising medications, although no pharmacologic treatment has emerged as clearly efficacious. In this review, we provide a detailed summary of clinical trials that evaluated psychotherapy and pharmacotherapy for treating CUD and discuss emerging areas of clinical research and cannabis-specific barriers to treatment.

Evaluation of the "Pipeline" for Development of Medications for Cocaine Use Disorder: A Review of Translational Preclinical, Human Laboratory, and Clinical Trial Research

Cocaine use disorder is a persistent public health problem for which no widely effective medications exist. Self-administration procedures, which have shown good predictive validity in estimating the abuse potential of drugs, have been used in rodent, nonhuman primate, and human laboratory studies to screen putative medications. This review assessed the effectiveness of the medications development process regarding pharmacotherapies for cocaine use disorder. The primary objective was to determine whether data from animal and human laboratory self-administration studies predicted the results of clinical trials. In addition, the concordance between laboratory studies in animals and humans was assessed. More than 100 blinded, randomized, fully placebo-controlled studies of putative medications for cocaine use disorder were identified. Of the 64 drugs tested in these trials, only 10 had been examined in both human and well-controlled animal laboratory studies. Within all three stages, few studies had been conducted for each drug and when multiple studies had been conducted conclusions were sometimes contradictory. Overall, however, there was good concordance between animal and human laboratory results when the former assessed chronic drug treatment. Although only seven of the ten reviewed drugs showed fully concordant results across all three types of studies reviewed, the analysis revealed several subject-related, procedural, and environmental factors that differ between the laboratory and clinical trial settings that help explain the disagreement for other drugs. The review closes with several recommendations to enhance translation and communication across stages of the medications development process that will ultimately speed the progress toward effective pharmacotherapeutic strategies for cocaine use disorder.

Further Evidence for Smoking and Substance Use Disorders in Youth With Bipolar Disorder and Comorbid Conduct Disorder

OBJECTIVE

Bipolar disorder (BPD) is a highly morbid disorder increasingly recognized in adolescents. The aim of this study was to examine the relative risk for substance use disorders (SUDs; alcohol or drug abuse or dependence) and cigarette smoking in adolescents with BPD.

METHODS

We evaluated the relative risk for SUDs and cigarette smoking in a case-controlled, 5-year prospective follow-up of adolescents with (n = 105, mean ± SD baseline age = 13.6 ± 2.5 years) and without ("controls"; n = 98, baseline age = 13.7 ± 2.1 years) BPD. Seventy-three percent of subjects were retained at follow-up (BPD: n = 68; controls: n = 81; 73% reascertainment). Our main outcomes were assessed by blinded structured interviews for DSM-IV criteria.

RESULTS

Maturing adolescents with BPD, compared to controls, were more likely to endorse higher rates of SUD (49% vs 26%; hazard ratio [HR] = 2.0; 95% confidence interval (CI), 1.1-3.6; P = .02) and cigarette smoking (49% vs 17%; HR = 2.9; 95% CI, 1.4-6.1; P = .004), as well as earlier onset of SUD (14.9 ± 2.6 [SD] years vs 16.5 ± 1.6 [SD] years; t = 2.6; P = .01). Subjects with conduct disorder (CD) were more likely to have SUD and nicotine dependence than subjects with BPD alone or controls (all P values < .05). When we added conduct disorder to the model with socioeconomic status and parental SUD, all associations lost significance (all P values > .05). Subjects with the persistence of a BPD diagnosis were also more likely to endorse cigarette smoking and SUD in comparison to those who lost a BPD diagnosis or controls at follow-up.

CONCLUSIONS

The results provide further evidence that adolescents with BPD, particularly those with comorbid CD, are significantly more likely to endorse cigarette smoking and SUDs when compared to their non-mood disordered peers. These findings indicate that youth with BPD should be carefully monitored for comorbid CD and the development of cigarette smoking and SUDs.

Glucocorticoid receptor gene modulates severity of depression in women with crack cocaine addiction

Crack cocaine addicted inpatients that present more severe withdrawal symptoms also exhibit higher rates of depressive symptoms. There is strong evidence that the identification of genetic variants in depression is potentialized when reducing phenotypic heterogeneity by studying selected groups. Since depression has been associated to dysregulation of the hypothalamic-pituitary-adrenal axis, this study evaluated the effects of SNPs in stress-related genes on depressive symptoms of crack cocaine addicts at early abstinence and over the detoxification treatment (4th, 11th and 18th day post admission). Also, the role of these SNPs on the re-hospitalization rates after 2.5 years of follow-up was studied. One hundred eight-two women were enrolled and eight SNPs in four genes (NR3C2, NR3C1, FKBP5 and CRHR1) were genotyped. A significant main effect of NR3C1-rs41423247 was found, where the C minor allele increased depressive symptoms at early abstinence. This effect remained significant after 10,000 permutations to account for multiple SNPs tested (P=0.0077). There was no effect of rs41423247 on the course of detoxification treatment, but a slight effect of rs41423247 at late abstinence was detected (P=0.0463). This analysis suggests that the presence of at least one C allele is worse at early abstinence, while only CC genotype appears to increase depressive symptoms at late abstinence. Also, a slight effect of rs41423247 C minor allele increasing the number of re-hospitalizations after 2.5 years was found (P=0.0413). These findings are in agreement with previous studies reporting an influence of rs41423247 on sensitivity to glucocorticoids and further elucidate its resulting effects on depressive-related traits.