Gender differences with high-dose naltrexone in patients with co-occurring cocaine and alcohol dependence

Examining gender in alcohol research: A systematic review of gender differences in how men and women are studied in alcohol research

BACKGROUND

This systematic review examined differences in the way women and men have been studied in alcohol research over the past decade. In particular, it explored differences in methodology, discipline, country, subpopulation and age focus, to understand who is being studied and how.

METHODS

Single-gender peer-reviewed studies on alcohol consumption published between 1st January 2014 and 31st December 2023 were identified by searching Medline, PsycInfo, Scopus and CINAHL. Descriptive statistics and comparisons to Global Burden of Disease [GBD] estimates are presented to understand whether the studies' gendered focus were proportionate to the distribution of alcohol-related harms. The review was registered with PROSPERO (CRD42022359103).

RESULTS

A total of 11,235 studies were identified, with 1,267 studies included. Despite consuming more alcohol and experiencing more harms, only 44% (n=554) of single gender studies were on men. One in three studies on men were from medical disciplines, whereas studies on women were more likely to come from psychology, public health or sociology disciplines. In several countries, including Australia, the disparity in the number of studies on women compared with GBD estimates of harms from alcohol consumption were particularly pronounced.

CONCLUSIONS

The majority of single-gender studies on alcohol consumption in the last decade focused on women. There has been strong focus on men's health (medical focus), and on women's behaviour (psychology, public health and sociology focus). Researchers' choices around study foci can differentially shape public discourse, policies and clinical practice, with important implications for gender equity and treatment outcomes.

Combined pharmacological and psychosocial interventions for alcohol use disorder

BACKGROUND

Alcohol use disorder (AUD) is a mental disorder characterised by a strong desire to consume alcohol and impaired control of alcohol use, with devastating consequences. Many people with AUD do not respond to psychosocial or pharmacological interventions when these are provided alone. Combining these interventions may improve the response to treatment, though evidence remains limited.

OBJECTIVES

To assess the effects of combined pharmacological and psychosocial interventions for the treatment of AUD in adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, three other databases, and two trials registers in November 2023, without language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing combined pharmacological and psychosocial interventions versus pharmacological or psychosocial interventions alone, or no intervention/treatment as usual (TAU), in adults with AUD. Our primary outcomes were continuous abstinent participants, frequency of use (measured as heavy drinkers, percentages of abstinent days, heavy-drinking days), amount of use (number of drinks per drinking day), adverse events, serious adverse events, dropouts from treatment, and dropouts due to adverse events.

DATA COLLECTION AND ANALYSIS

We assessed risk of bias using Cochrane's RoB 1 tool, performed random-effects meta-analyses, and evaluated the certainty of evidence according to the GRADE approach.

MAIN RESULTS

We included 21 RCTs (4746 participants). The most studied pharmacological and psychosocial interventions were naltrexone (81.0%) and cognitive behavioural therapy (66.7%), respectively. Most participants were men (74%), aged about 44 years, with AUD, without comorbid mental disorders or other substance use disorders; 15 RCTs detoxified participants before treatment. We judged 28.5% of the studies as at low risk of bias for random sequence generation, allocation concealment, performance bias for objective and subjective outcomes, and detection bias for subjective outcomes; all studies were at low risk of detection bias for objective outcomes; 85.7% of studies were at low risk of attrition bias; 14.2% of studies were at low risk of reporting bias. 1) Compared to psychosocial intervention alone, combined pharmacological and psychosocial interventions probably reduce the number of heavy drinkers (above the clinically meaningful threshold (MID) of 2%; absolute difference (AD) -10%, 95% confidence interval (CI) -18% to -2%; risk ratio (RR) 0.86, 95% CI 0.76 to 0.97; 8 studies, 1609 participants; moderate-certainty evidence). They may increase continuous abstinent participants (MID 5%; AD 5%, 95% CI 1% to 11%; RR 1.17, 95% CI 1.02 to 1.34; 6 studies, 1184 participants; low-certainty evidence). They probably have little to no effect on: • the rate of abstinent days (MID 8%; mean difference (MD) 4.16, 95% CI 1.24 to 7.08; 10 studies, 2227 participants); • serious adverse events (MID 1%; AD -2%, 95% CI -3% to 0%; RR 0.20, 95% CI 0.03 to 1.12; 4 studies; 524 participants); • dropouts from treatment (MID 10%; AD -3%, 95% CI -5% to 0%; RR 0.89, 95% CI 0.79 to 1.01; 15 studies, 3021 participants); and • dropouts due to adverse events (MID 5%; AD 2%, 95% CI 0% to 5%; RR 1.91, 95% CI 1.04 to 3.52; 8 studies, 1572 participants) (all moderate-certainty evidence). They may have little to no effect on: • heavy-drinking days (MID 5%; MD -3.49, 95% CI -8.68 to 1.70; 4 studies, 470 participants); • number of drinks per drinking day (MID 1 drink; MD -0.57, 95% CI -1.16 to 0.01; 7 studies, 805 participants); and • adverse events (MID 30%; AD 17%, 95% CI -5% to 46%; RR 1.25, 95% CI 0.93 to 1.68; 4 studies, 508 participants) (all low-certainty evidence). 2) Compared to pharmacological intervention alone, combined pharmacological and psychosocial interventions may have little to no effect on: • the rate of abstinent days (MID 8%; MD -1.18, 95% CI -4.42 to 2.07; 2 studies, 1158 participants); and • dropouts from treatment (MID 10%; AD 1%, 95% CI -10 to 14%; RR 0.98, 95% CI 0.65 to 1.47; 3 studies, 1246 participants) (all low-certainty evidence). We are uncertain about their effect on: • continuous abstinent participants (MID 5%; AD 3%, 95% CI -5% to 18%; RR 1.22, 95% CI 0.62 to 2.40; 1 study, 241 participants); • the number of heavy drinkers (MID 2%; AD 2%, 95% CI -4% to 8%; RR 1.03, 95% CI 0.94 to 1.12; 1 study, 917 participants); • the number of drinks per drinking day (MID 1 drink; MD -2.40, 95% CI -3.98 to -0.82; 1 study, 241 participants); and • dropouts due to adverse events (MID 5%; AD -1%, 95% CI -3% to 6%; RR 0.61, 95% CI 0.14 to 2.72; 2 studies, 1165 participants) (all very low-certainty evidence). 3) We are uncertain about the effect of combined pharmacological and psychosocial interventions, when compared to TAU, on: • the number of heavy drinkers (MID 2%; AD -5%, 95% CI -13% to 2%; RR 0.93, 95% CI 0.83 to 1.03; 1 study, 616 participants); • the rate of abstinent days (MID 8%; MD 3.43, 95% CI -1.32 to 8.18; 1 study, 616 participants); • dropouts from treatment (MID 10%; AD 0%, 95% CI -10% to 15%; RR 0.98, 95% CI 0.58 to 1.65; 2 studies, 696 participants); and • dropouts due to adverse events (MID 5%; AD 3%, 95% CI 0% to 15%; RR 2.97, 95% CI 0.70 to 12.67; 1 study, 616 participants) (all very low-certainty evidence). The certainty of evidence ranged from moderate to very low, downgraded mainly due to risk of bias and imprecision.

AUTHORS' CONCLUSIONS

As implications for practice, our findings indicate that adding pharmacological to psychosocial interventions is safe and helps people with AUD recover. These conclusions are based on low- to moderate-certainty evidence. Given the few studies and very low-certainty evidence, any benefits of adding psychosocial to pharmacological interventions or comparing the combined intervention to TAU are less clear. As implications for research, further studies should investigate the effects of the combined intervention compared to pharmacotherapy or TAU.

Rethinking gender differences: An investigation of comorbid psychopathology and alcohol use disorder in veterans

BACKGROUND

While men have been found to drink more alcohol and have higher rates of alcohol-related mortality, women tend to experience higher rates of alcohol-related consequences, including psychological comorbidities and worse alcohol use disorder (AUD) outcomes. However, gender differences in comorbid psychopathology and associations with AUD outcomes among veterans are less well understood.

METHODS

Veterans (N = 126; 32 women) receiving inpatient treatment for AUD completed baseline clinical measures including the Beck Depression Inventory-II, Beck Anxiety Inventory, Early Life Stress Questionnaire, and PTSD Checklist for DSM-5. Alcohol use was assessed with the Timeline Followback for the 90 days prior to the baseline assessment and again at 1-, 3-, and 6-month follow-ups. Gender differences in baseline alcohol and psychopathology measures were examined using Fisher's exact test and Mann-Whitney U test. Linear/logistic regression was used to examine associations between comorbid psychopathology and alcohol relapse/use severity post-study.

RESULTS

Consistent with prior literature, statistically significant gender differences in psychopathology were observed, with women reporting higher anxiety (p < 0.001), depression (p = 0.001), early life stress (p < 0.001), and PTSD (p < 0.001) at baseline. Higher early life stress was also associated with higher anxiety, depression, and PTSD. Statistically significant gender differences were not observed for alcohol use in the 90 days prior to the study. Similarly, gender was not associated with relapse or severity of use at 1-, 3-, or 6-month follow ups (ps > 0.05). Psychopathology measures were not associated with relapse or severity of use at any time point (ps > 0.05).

CONCLUSION

Our study highlights that women veterans are drinking similar quantities of alcohol to men, supporting emerging evidence of a narrowing gender gap in alcohol use. Women also have a higher psychiatric burden than men; thus, identifying ways to mitigate comorbidity among women veterans should be a health priority.

A narrative review on alcohol use in women: insight into the telescoping hypothesis from a biopsychosocial perspective

Background: There has been a dramatic rise in alcohol consumption and alcohol use disorder (AUD) among women. Recently, the field has made substantial progress toward better understanding sex and gender differences in AUD. This research has suggested accelerated progression to AUD and associated health consequences in women, a phenomenon referred to as "telescoping."Objective: To examine evidence for the telescoping hypothesis from a biopsychosocial perspective.Methods: This narrative review examined and integrated research on biological, psychological, and socio-environmental factors that may contribute to the development and progression of AUD in women.Results: Biopsychosocial research has revealed sex- and gender-specific risk factors and pathways to AUD onset and progression. Biological sex differences render females more vulnerable to alcohol-related toxicity across various biological systems, including the brain. Notably, sex and gender differences are consistently observed in the neural circuitry underlying emotional and stress regulation, and are hypothesized to increase risk for an internalizing pathway to AUD in women. Psychological research indicates women experience greater negative emotionality and are more likely to use alcohol as a means to alleviate negative emotions compared with men. Socio-environmental factors, such as familial and peer isolation, appear to interact with biological and psychological processes in a way that increases risk for negative emotionality and associated alcohol use in women.Conclusion: There appears to be a complex interplay of biopsychosocial factors that increase risk for AUD onset and progression in women through an internalizing pathway. Developing targeted interventions for women with AUD that specifically target internalizing processes is critical.

Efficacy of medications for the treatment of alcohol use disorder (AUD): A systematic review and meta-analysis considering baseline AUD severity

Baseline severity of alcohol use disorder (AUD) is an influencing factor in the response to medications recommended for the treatment of AUD. The scarce efficacy of AUD medications partly justifies their limited uses. We were interested in evaluating the efficacy of approved and recommended AUD medications using generic inverse-variance, an analysis facilitating comparison between medications and placebo both at the end of the study and, concomitantly, to baseline values for the same participants. We conducted a systematic review to include randomized controlled trials (RCTs) comparing any medication to placebo providing, both at baseline and end of treatment, percent heavy drinking days (%HDD), percent drinking days (%DD), and/or drinks per drinking day (DDD). We searched PubMed, Embase, PMC, and three CT registers from inception to April 2023. A total of 79 RCTs (11,737 AUD participants; 30 different medications) were included: 47 RCTs (8465 participants) used AUD medications, and 32 RCTs (3272 participants) used other medications. At baseline, participants consumed on average approximately 12 DDD, and experienced 70 % DD, and 61 % HDD. Placebo halved or reduced these values to a third. Compared to placebo, AUD medications further reduced these outcomes (moderate to high certainty evidence). Other medications reduced the DDD without modifying other alcohol outcomes. AUD medications increased the risk of developing adverse events (high-certainty evidence). Despite the large placebo effects, our results support the benefits of providing AUD medications to people with AUD, helping them reduce alcohol consumption.

Adjunctive Medication Management and Contingency Management to enhance adherence to acamprosate for alcohol dependence: the ADAM trial RCT

Background

Acamprosate is an effective and cost-effective medication for alcohol relapse prevention but poor adherence can limit its full benefit. Effective interventions to support adherence to acamprosate are therefore needed.

Objectives

To determine the effectiveness of Medication Management, with and without Contingency Management, compared to Standard Support alone in enhancing adherence to acamprosate and the impact of adherence to acamprosate on abstinence and reduced alcohol consumption.

Design

Multicentre, three-arm, parallel-group, randomised controlled clinical trial.

Setting

Specialist alcohol treatment services in five regions of England (South East London, Central and North West London, Wessex, Yorkshire and Humber and West Midlands).

Participants

Adults (aged 18 years or more), an International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, diagnosis of alcohol dependence, abstinent from alcohol at baseline assessment, in receipt of a prescription for acamprosate.

Interventions

(1) Standard Support, (2) Standard Support with adjunctive Medication Management provided by pharmacists via a clinical contact centre (12 sessions over 6 months), (3) Standard Support with adjunctive Medication Management plus Contingency Management that consisted of vouchers (up to £120) to reinforce participation in Medication Management. Consenting participants were randomised in a 2 : 1 : 1 ratio to one of the three groups using a stratified random permuted block method using a remote system. Participants and researchers were not blind to treatment allocation.

Main outcome measures

Primary outcome: self-reported percentage of medication taken in the previous 28 days at 6 months post randomisation. Economic outcome: EuroQol-5 Dimensions, a five-level version, used to calculate quality-adjusted life-years, with costs estimated using the Adult Service Use Schedule.

Results

Of the 1459 potential participants approached, 1019 (70%) were assessed and 739 (73 consented to participate in the study, 372 (50%) were allocated to Standard Support, 182 (25%) to Standard Support with Medication Management and 185 (25%) to Standard Support and Medication Management with Contingency Management. Data were available for 518 (70%) of participants at 6-month follow-up, 255 (68.5%) allocated to Standard Support, 122 (67.0%) to Standard Support and Medication Management and 141 (76.2%) to Standard Support and Medication Management with Contingency Management. The mean difference of per cent adherence to acamprosate was higher for those who received Standard Support and Medication Management with Contingency Management (10.6%, 95% confidence interval 19.6% to 1.6%) compared to Standard Support alone, at the primary end point (6-month follow-up). There was no significant difference in per cent days adherent when comparing Standard Support and Medication Management with Standard Support alone 3.1% (95% confidence interval 12.8% to -6.5%) or comparing Standard Support and Medication Management with Standard Support and Medication Management with Contingency Management 7.9% (95% confidence interval 18.7% to -2.8%). The primary economic analysis at 6 months found that Standard Support and Medication Management with Contingency Management was cost-effective compared to Standard Support alone, achieving small gains in quality-adjusted life-years at a lower cost per participant. Cost-effectiveness was not observed for adjunctive Medication Management compared to Standard Support alone. There were no serious adverse events related to the trial interventions reported.

Limitations

The trial's primary outcome measure changed substantially due to data collection difficulties and therefore relied on a measure of self-reported adherence. A lower than anticipated follow-up rate at 12 months may have lowered the statistical power to detect differences in the secondary analyses, although the primary analysis was not impacted.

Conclusions

Medication Management enhanced with Contingency Management is beneficial to patients for supporting them to take acamprosate.

Future work

Given our findings in relation to Contingency Management enhancing Medication Management adherence, future trials should be developed to explore its effectiveness and cost-effectiveness with other alcohol interventions where there is evidence of poor adherence.

Trial registration

This trial is registered as ISRCTN17083622 https://doi.org/10.1186/ISRCTN17083622.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 22. See the NIHR Journals Library website for further project information.

A gender-based secondary analysis of the ADAPT-2 combination naltrexone and bupropion treatment for methamphetamine use disorder trial

BACKGROUND AND AIMS

Socio-cultural (gender) and biological (sex)-based differences contribute to psychostimulant susceptibility, potentially affecting treatment responsiveness among women with methamphetamine use disorder (MUD). The aims were to measure (i) how women with MUD independently and compared with men respond to treatment versus placebo and (ii) among women, how the hormonal method of contraception (HMC) affects treatment responsiveness.

DESIGN

This was a secondary analysis of ADAPT-2, a randomized, double-blind, placebo-controlled, multicenter, two-stage sequential parallel comparison design trial.

SETTING

United States.

PARTICIPANTS

This study comprised 126 women (403 total participants); average age = 40.1 years (standard deviation = 9.6) with moderate to severe MUD.

INTERVENTIONS

Interventions were combination intramuscular naltrexone (380 mg/3 weeks) and oral bupropion (450 mg daily) versus placebo.

MEASUREMENTS

Treatment response was measured using a minimum of three of four negative methamphetamine urine drug tests during the last 2 weeks of each stage; treatment effect was the difference between weighted treatment responses of each stage.

FINDINGS

At baseline, women used methamphetamine intravenously fewer days than men [15.4 versus 23.1% days, P = 0.050, difference = -7.7, 95% confidence interval (CI) = -15.0 to -0.3] and more women than men had anxiety (59.5 versus 47.6%, P = 0.027, difference = 11.9%, 95% CI = 1.5 to 22.3%). Of 113 (89.7%) women capable of pregnancy, 31 (27.4%) used HMC. In Stage 1 29% and Stage 2 5.6% of women on treatment had a response compared with 3.2% and 0% on placebo, respectively. A treatment effect was found independently for females and males (P < 0.001); with no between-gender treatment effect (0.144 females versus 0.100 males; P = 0.363, difference = 0.044, 95% CI = -0.050 to 0.137). Treatment effect did not differ by HMC use (0.156 HMC versus 0.128 none; P = 0.769, difference = 0.028, 95% CI -0.157 to 0.212).

CONCLUSIONS

Women with methamphetamine use disorder receiving combined intramuscular naltrexone and oral bupropion treatment achieve greater treatment response than placebo. Treatment effect does not differ by HMC.

Influence of sex in alcohol-related liver disease: Pre-clinical and clinical settings

Alcohol-related liver disease (ArLD) is a major cause of chronic liver disease globally. Traditionally, ArLD was mostly a concern in men rather than in women; however, such a sex gap is rapidly narrowing due to increasing chronic alcohol consumption among women. Female sex is more vulnerable to the harmful effects of alcohol with a higher risk of progression to cirrhosis and development of associated complications. The relative risk of cirrhosis and liver-related mortality is significantly higher in women than in men. Our review endeavors to summarize the current knowledge on sex differences in alcohol metabolism, pathogenesis of ArLD, disease progression, indication for liver transplant and pharmacological treatments of ArLD, and provide evidence in support of a sex-specific management of these patients.

Lack of attention to sex and gender in periodontitis-related randomized clinical trials: A meta-research study

AIM

This meta-research study aimed to investigate the level of compliance with the Sex and Gender Equity in Research (SAGER) Guidelines for the inclusion, analysis, and reporting of sex/gender, in periodontitis-related randomized controlled trials (RCTs).

MATERIALS AND METHODS

Following the inclusion of RCTs related to the treatment of periodontitis published between 2018 and 2019, we applied the SAGER checklist to assess the adherence to sex/gender reporting guidelines. We used non-parametric descriptive statistics and correlation models to test the association of the dependent outcome with other variables.

RESULTS

One hundred and one articles were included in the analysis. The female enrolment ranged between 30% and 94%. Twenty-six studies enrolled less than 50% of female participants. The overall SAGER score (OSS) of item fulfilment ranged between 0 and 7 items with an average of 1.9 items signifying poor guideline adherence to the SAGER guidelines. These findings were not associated with the corresponding author gender (p = .623), publication year (p = .947), and funding source (p = .133). However, a significant but negative correlation with journal impact factor (r = -0.253, p = .026) was observed.

CONCLUSIONS

Sex and gender were frequently disregarded in clinical trial reporting. This oversight might limit the understanding of sex/gender differences in periodontitis-related clinical trials.

Distress tolerance: prospective associations with cognitive-behavioral therapy outcomes in adults with posttraumatic stress and substance use disorders

74Distress tolerance (DT; perceived or actual ability to tolerate aversive physical or emotional states) is related to both posttraumatic stress disorder (PTSD) symptoms and substance use disorders (SUD). This investigation evaluates self-report and behavioral measures of DT as potential predictors of PTSD and SUD cognitive-behavioral therapy outcomes. Participants included 41 treatment-seeking adults (53.7% women; 73.2% African American; Mage = 44.90, SD = 9.68) who met at least four symptoms of DSM-5 PTSD and DSM-IV substance dependence, assessed via structured interviews. At baseline (pre-treatment), participants completed the Distress Tolerance Scale (DTS), Mirror-Tracing Persistence Task (MTPT), Breath Holding task, and Paced Auditory Serial Addition Task. The Clinician-Administered PTSD Scale for DSM-5 severity scores and percent days of primary substance use, measured via Timeline Follow-back, were used as indicators of PTSD symptoms and substance use, respectively. Covariates included treatment condition, baseline PTSD symptom severity, and baseline substance use. Lower perceived DT at baseline (DTS total score) was associated with higher PTSD symptom severity at end-of-treatment. Lower behavioral DT at baseline (MTPT duration) was associated with higher substance use at the conclusion of treatment (i.e. proportion of number of use days to total number of days between two final treatment sessions).

Consideration of sex and gender differences in addiction medication response

Substance use continues to contribute to significant morbidity and mortality in the United States, for both women and men, more so than another other preventable health condition. To reduce the public health burden attributable to substances, the National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism have identified that medication development for substance use disorder is a high priority research area. Furthermore, both Institutes have stated that research on sex and gender differences in substance use medication development is a critical area. The purpose of the current narrative review is to highlight how sex and gender have been considered (or not) in medication trials for substance use disorders to clarify and summarize what is known regarding sex and gender differences in efficacy and to provide direction to the field to advance medication development that is consistent with current NIH 'sex as a biological variable' (SABV) policy. To that end, we reviewed major classes of abused substances (nicotine, alcohol, cocaine, cannabis, opioids) demonstrating that, sex and gender have not been well-considered in addiction medication development research. However, when adequate data on sex and gender differences have been evaluated (i.e., in tobacco cessation), clinically significant differences in response have been identified between women and men. Across the other drugs of abuse reviewed, data also suggest sex and gender may be predictive of outcome for some agents, although the relatively low representation of women in clinical research samples limits making definitive conclusions. We recommend the incorporation of sex and gender into clinical care guidelines and improved access to publicly available sex-stratified data from medication development investigations.

Occupancy of the kappa opioid receptor by naltrexone predicts reduction in drinking and craving

The efficacy of naltrexone to treat alcohol use disorder (AUD) is modest. A better understanding of the neurobiology underlying naltrexone effects could optimize treatments. We evaluated the occupancy of the kappa opioid receptor (KOR) by naltrexone measured with [11C]-LY2795050 positron emission tomography (PET) as a predictor of response to naltrexone. Response to naltrexone was defined as the difference in craving and the difference between the number of drinks consumed during an alcohol drinking paradigm (ADP) before and after 1 week of supervised 100 mg daily oral naltrexone. Forty-four (14 F) nontreatment seeking heavy drinkers meeting criteria for AUD were enrolled. Participants drank 47 ± 16 drinks per week and were balanced in family history of alcoholism (FH, 26 positive). High KOR occupancy (92 ± 1%) was achieved. Occupancy was negatively associated with number of years drinking (YOD) in FH positive, but not FH negative, participants (t3,42 = 4.00, p = 0.0003). Higher KOR occupancy by naltrexone was associated with higher alcohol craving during the ADP (F1,81 = 4.88, p = 0.030). The reduction in drinking after naltrexone was negatively associated with KOR occupancy, with significant effects of FH status (t1,43 = -2.08, p = 0.044). A logistic regression model including KOR occupancy, YOD, and FH variables achieved an 84% prediction accuracy for ≥50% reduction in drinking. These results confirm that naltrexone binds at the KOR site and suggest that KOR occupancy by naltrexone may be related to clinical response. Based on our results, we propose that differential affinities for the mu and KOR could explain why lower doses of naltrexone can have greater clinical efficacy.

Alterations in reward network functional connectivity are associated with increased food addiction in obese individuals

Functional neuroimaging studies in obesity have identified alterations in the connectivity within the reward network leading to decreased homeostatic control of ingestive behavior. However, the neural mechanisms underlying sex differences in the prevalence of food addiction in obesity is unknown. The aim of the study was to identify functional connectivity alterations associated with: (1) Food addiction, (2) Sex- differences in food addiction, (3) Ingestive behaviors. 150 participants (females: N = 103, males: N = 47; food addiction: N = 40, no food addiction: N = 110) with high BMI ≥ 25 kg/m2 underwent functional resting state MRIs. Participants were administered the Yale Food Addiction Scale (YFAS), to determine diagnostic criteria for food addiction (YFAS Symptom Count ≥ 3 with clinically significant impairment or distress), and completed ingestive behavior questionnaires. Connectivity differences were analyzed using a general linear model in the CONN Toolbox and images were segmented using the Schaefer 400, Harvard-Oxford Subcortical, and Ascending Arousal Network atlases. Significant connectivities and clinical variables were correlated. Statistical significance was corrected for multiple comparisons at q < .05. (1) Individuals with food addiction had greater connectivity between brainstem regions and the orbital frontal gyrus compared to individuals with no food addiction. (2) Females with food addiction had greater connectivity in the salience and emotional regulation networks and lowered connectivity between the default mode network and central executive network compared to males with food addiction. (3) Increased connectivity between regions of the reward network was positively associated with scores on the General Food Cravings Questionnaire-Trait, indicative of greater food cravings in individuals with food addiction. Individuals with food addiction showed greater connectivity between regions of the reward network suggesting dysregulation of the dopaminergic pathway. Additionally, greater connectivity in the locus coeruleus could indicate that the maladaptive food behaviors displayed by individuals with food addiction serve as a coping mechanism in response to pathological anxiety and stress. Sex differences in functional connectivity suggest that females with food addiction engage more in emotional overeating and less cognitive control and homeostatic processing compared to males. These mechanistic pathways may have clinical implications for understanding the sex-dependent variability in response to diet interventions.

Sex and Gender Effects in Recovery From Alcohol Use Disorder

The current article provides a brief summary of biopsychosocial gender differences in alcohol use disorder (AUD), then reviews existing literature on gender differences in treatment access, retention, outcomes, and longer-term recovery. Among psychotherapies for AUD, there is support for the efficacy of providing female-specific treatment, and for female-only treatment settings but only when female-specific treatment is included. However, despite mandates from the National Institutes of Health to do so, there is little work thus far that directly compares genders on outcomes of specific psychotherapies or pharmacotherapies for AUD. Although existing research has mixed findings on sex and gender differences in overall outcomes, there are more consistent findings suggesting different mechanisms of behavior change among men and women in AUD treatment and long-term recovery. Thus, more work is needed that attends to gender and sex differences, including planning studies that are structured to examine not only gender-differentiated outcomes in treatment response, but equally important, differences in treatment access and attendance as well as differences in mechanisms of change in drinking behavior.

Evidence-Based Pharmacotherapies for Alcohol Use Disorder: Clinical Pearls

Pathologic alcohol use affects more than 2 billion people and accounts for nearly 6% of all deaths worldwide. There are three medications approved for the treatment of alcohol use disorder by the US Food and Drug Administration (FDA): disulfiram, naltrexone (oral and long-acting injectable), and acamprosate. Of growing interest is the use of anticonvulsants for the treatment of alcohol use disorder, although currently none are FDA approved for this indication. Baclofen, a γ-aminobutyric acid B receptor agonist used for spasticity and pain, received temporary approval for alcohol use disorder in France. Despite effective pharmacotherapies, less than 9% of patients who undergo any form of alcohol use disorder treatment receive pharmacotherapies. Current evidence does not support the use of pharmacogenetic testing for treatment individualization. The objective of this review is to provide knowledge on practice parameters for evidenced-based pharmacologic treatment approaches in patients with alcohol use disorder.

Combined Pharmacotherapy and Cognitive Behavioral Therapy for Adults With Alcohol or Substance Use Disorders: A Systematic Review and Meta-analysis

IMPORTANCE

Substance use disorders (SUDs) represent a pressing public health concern. Combined behavioral and pharmacological interventions are considered best practices for addiction. Cognitive behavioral therapy (CBT) is a first-line intervention, yet the superiority of CBT compared with other behavioral treatments when combined with pharmacotherapy remains unclear. An understanding of the effects of combined CBT and pharmacotherapy will inform best-practice guidelines for treatment of SUD.

OBJECTIVE

To conduct a meta-analysis of the published literature on combined CBT and pharmacotherapy for adult alcohol use disorder (AUD) or other SUDs.

DATA SOURCES

PubMed, Cochrane Register, MEDLINE, PsychINFO, and Embase databases from January 1, 1990, through July 31, 2019, were searched. Keywords were specified in 3 categories: treatment type, outcome type, and study design. Collected data were analyzed through September 30, 2019.

STUDY SELECTION

Two independent raters reviewed abstracts and full-text articles. English language articles describing randomized clinical trials examining CBT in combination with pharmacotherapy for AUD and SUD were included.

DATA EXTRACTION AND SYNTHESIS

Inverse-variance weighted, random-effects estimates of effect size were pooled into 3 clinically informative subgroups: (1) CBT plus pharmacotherapy compared with usual care plus pharmacotherapy, (2) CBT plus pharmacotherapy compared with another specific therapy plus pharmacotherapy, and (3) CBT added to usual care and pharmacotherapy compared with usual care and pharmacotherapy alone. Sensitivity analyses included assessment of study quality, pooled effect size heterogeneity, publication bias, and primary substance moderator effects.

MAIN OUTCOMES AND MEASURES

Substance use frequency and quantity outcomes after treatment and during follow-up were examined.

RESULTS

The sample included 62 effect sizes from 30 unique randomized clinical trials that examined CBT in combination with some form of pharmacotherapy for AUD and SUD. The primary substances targeted in the clinical trial sample were alcohol (15 [50%]), followed by cocaine (7 [23%]) and opioids (6 [20%]). The mean (SD) age of the patient sample was 39 (6) years, with a mean (SD) of 28% (12%) female participants per study. The following pharmacotherapies were used: naltrexone hydrochloride and/or acamprosate calcium (26 of 62 effect sizes [42%]), methadone hydrochloride or combined buprenorphine hydrochloride and naltrexone (11 of 62 [18%]), disulfiram (5 of 62 [8%]), and another pharmacotherapy or mixture of pharmacotherapies (20 of 62 [32%]). Random-effects pooled estimates showed a benefit associated with combined CBT and pharmacotherapy over usual care (g range, 0.18-0.28; k = 9). However, CBT did not perform better than another specific therapy, and evidence for the addition of CBT as an add-on to combined usual care and pharmacotherapy was mixed. Moderator analysis showed variability in effect direction and magnitude by primary drug target.

CONCLUSIONS AND RELEVANCE

The present study supports the efficacy of combined CBT and pharmacotherapy compared with usual care and pharmacotherapy. Cognitive behavioral therapy did not perform better than another evidence-based modality (eg, motivational enhancement therapy, contingency management) in this context or as an add-on to combined usual care and pharmacotherapy. These findings suggest that best practices in addiction treatment should include pharmacotherapy plus CBT or another evidence-based therapy, rather than usual clinical management or nonspecific counseling services.

Clinical effects beyond cocaine use of sustained-release dexamphetamine for the treatment of cocaine dependent patients with comorbid opioid dependence: secondary analysis of a double-blind, placebo-controlled randomized trial

BACKGROUND AND AIMS

Sustained-release (SR) formulations of dexamphetamine and mixed amphetamine salts have shown positive effects in the treatment of patients with a cocaine use disorder. We previously demonstrated the efficacy of SR-dexamphetamine for patients with cocaine dependence in terms of cocaine use reductions. In this secondary analysis, we assessed whether SR-dexamphetamine treatment also improves the health status of these patients.

DESIGN

Multi-centre randomized, double-blind placebo-controlled trial.

SETTING

Four supervised heroin-assisted treatment (HAT) out-patient clinics in the Netherlands. In HAT, methadone treatment-refractory opioid-dependent patients can self-administer individually titrated doses of pharmaceutical grade diacetylmorphine, coprescribed with oral methadone.

PARTICIPANTS

Seventy-three cocaine-dependent patients (90% males; average age = 48.7 years), participating in HAT for their treatment-refractory comorbid opioid dependence.

INTERVENTIONS

Twelve weeks pharmacotherapy with once-daily, supervised intake of two tablets of SR-dexamphetamine (2 × 30 mg/day) or two identical placebo tablets.

MEASUREMENTS

Assessment every 4 weeks: cocaine use (time-line follow-back), physical health (Maudsley Addiction Profile-Health Symptoms Scale), mental health (Brief Symptom Inventory) and illegal activities (Addiction Severity Index). Primary outcome was 'overall health', a dichotomous, multi-domain response index based on physical health, mental health and social functioning.

FINDINGS

Compared with placebo, SR-dexamphetamine resulted in larger increases in the number of cocaine abstinent days (P = 0.004) and the proportion of overall health treatment responders (P = 0.045) from the 4 weeks preceding baseline to the final 4 weeks of treatment. While the number of cocaine abstinent days was not associated with overall health in the total study sample, it was positively associated with overall health among patients in poor overall health at the start of SR-dexamphetamine treatment (n = 50), i.e. patients with the potential to improve on this multi-domain response index (odds ratio = 1.076; 95% confidence interval = 1.025-1.130).

CONCLUSIONS

SR-dexamphetamine reduces cocaine use and may improve clinically relevant health-related outcomes in patients with cocaine dependence who are participating in heroin-assisted treatment for their comorbid heroin dependence.

Sex- and Gender-Based Analysis in Cannabis Treatment Outcomes: A Systematic Review

There is evidence that sex- and gender-related factors are involved in cannabis patterns of use, health effects and biological mechanisms. Women and men report different cannabis use disorder (CUD) symptoms, with women reporting worse withdrawal symptoms than men. The objective of this systematic review was to examine the effectiveness of cannabis pharmacological interventions for women and men and the uptake of sex- and gender-based analysis in the included studies. Two reviewers performed the full-paper screening, and data was extracted by one researcher. The search yielded 6098 unique records—of which, 68 were full-paper screened. Four articles met the eligibility criteria for inclusion. From the randomized clinical studies of pharmacological interventions, few studies report sex-disaggregated outcomes for women and men. Despite emergent evidence showing the influence of sex and gender factors in cannabis research, sex-disaggregated outcomes in pharmacological interventions is lacking. Sex- and gender-based analysis is incipient in the included articles. Future research should explore more comprehensive inclusion of sex- and gender-related aspects in pharmacological treatments for CUD.

Clinical Trials for Stimulant Use Disorders: Addressing Heterogeneities That May Undermine Treatment Outcomes

In recent years, use of cocaine and amphetamines and deaths associated with stimulants have been on the rise, and there are still no FDA-approved medications for stimulant use disorders. One contributing factor may involve heterogeneity. At the neurobiological level, dual dopamine dysfunction may be undermining medication efficacy, suggesting a need for combination pharmacotherapies. At the population level, individual variability is expressed in a number of ways and, if left unaddressed, may interfere with medication efficacy. This chapter reviews studies investigating medications to address dopamine dysfunction, and it also identifies several prominent heterogeneities associated with stimulant (and other substance) use disorders. The chapter has implications for improving interventions to treat stimulant use disorders, and the theme of individual heterogeneity may have broader application across substance use disorders.

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.

Sex differences in the pharmacology of itch therapies-a narrative review

BACKGROUND

Chronic itch is the most common skin-related condition, associated with a high psychosocial and economic burden. In recent years, increasing evidence of sex differences in the perception, clinical presentation and treatment requirements of itch points towards potential benefits when using sex-adapted therapies. It is well-known that body composition, absorption, metabolism, elimination and adverse drug reactions (ADRs) differ between sexes, but only little is known about the impact of sex in the pharmacology of itch treatments, which could help to rationalise sex-adapted treatment strategies.

AIM

To evaluate and review sex effects in the pharmacokinetics and /-dynamics of drugs used to treat itch.

METHODS

In this narrative review we performed a PubMed and MEDLINE (Ovid) search using the terms (itch OR pruritus) AND (gender OR sex) AND (drug OR medication OR pharmacokinetics OR pharmacodynamics). Additional searches were performed for the topical and systemic drugs recommended by the European Guideline on Chronic Pruritus.

RESULTS

We found numerous reports with variable levels of evidence of sex effects with respect to the pharmacokinetics and/or pharmacodynamics of 14 drug classes used for the treatment of itch, including a total of 19 systemic and 3 topical drugs. Women seem to present higher plasma levels of several drugs used in itch treatment, including tri- and tetracyclic antidepressants (e.g. doxepin, amitriptyline, mirtazapine), serotonin reuptake inhibitors (e.g. paroxetine, sertraline, fluoxetine), immunosuppressive drugs (e.g. cyclosporine, mycophenolate mofetil), serotonin receptor antagonists (e.g. ondansetron) and betablockers (e.g. propranolol). Adverse drug reactions (ADRs) were generally more common in women. Being female was reported to be an independent risk factor for QTc-prolongation associated with antihistamines and tetracyclic antidepressants. Additionally, women seem to be more prone to sedative effects of antihistamines, and to suffer from a higher frequency as well as severity of side effects with systemic calcineurin inhibitors, opioid agonists, and opioid antagonists. Women were also sensitised more often to topically applied drugs. Of note, apart from only one experimental study with capsaicin, none of these reports were designed specifically to assess the effect of sex (and gender) in the treatment of itch.

DISCUSSION/CONCLUSION

Our review supports previous reports that sex is of importance in the pharmacokinetics and /-dynamics of several drugs used to treat itch although those drugs were mostly evaluated for non-itch indications. However, the results are limited by methodological limitations evident in most studies such as underrepresentation of women in clinical trials. This emphasises the need to study the impact of sex (and gender) in future itch trials to yield better outcomes and prevent ADRs in both sexes.

Gender inequality and restrictive gender norms: framing the challenges to health

Gender is not accurately captured by the traditional male and female dichotomy of sex. Instead, it is a complex social system that structures the life experience of all human beings. This paper, the first in a Series of five papers, investigates the relationships between gender inequality, restrictive gender norms, and health and wellbeing. Building upon past work, we offer a consolidated conceptual framework that shows how individuals born biologically male or female develop into gendered beings, and how sexism and patriarchy intersect with other forms of discrimination, such as racism, classism, and homophobia, to structure pathways to poor health. We discuss the ample evidence showing the far-reaching consequences of these pathways, including how gender inequality and restrictive gender norms impact health through differential exposures, health-related behaviours and access to care, as well as how gender-biased health research and health-care systems reinforce and reproduce gender inequalities, with serious implications for health. The cumulative consequences of structured disadvantage, mediated through discriminatory laws, policies, and institutions, as well as diet, stress, substance use, and environmental toxins, have triggered important discussions about the role of social injustice in the creation and maintenance of health inequities, especially along racial and socioeconomic lines. This Series paper raises the parallel question of whether discrimination based on gender likewise becomes embodied, with negative consequences for health. For decades, advocates have worked to eliminate gender discrimination in global health, with only modest success. A new plan and new political commitment are needed if these global health aspirations and the wider Sustainable Development Goals of the UN are to be achieved.

What happens to agreement over time? A longitudinal study of self-reported substance use compared to saliva toxicological testing among subsidized housing residents

The agreement between self-reported and toxicologically verified substance use provides important information about the validity of self-reported use. While some studies report aggregate agreement across follow-up points, only a few have examined the agreement at each time point separately. An overall rate of agreement across time may miss changes that occur as people progress through a research study. In this study, a sample of 644 adults (43.8% male, 32.6% White, 57.0% Black, 90.2% ages 36+) residing in subsidized housing was used to determine the agreement between self-reported use and saliva toxicological testing for marijuana, cocaine, PCP, amphetamine, and methamphetamine at three different time points. Agreement between saliva toxicological testing and self-report ranged between 84.2% and 94.3% for different substances over time. Higher rates of agreement were found for cocaine than had been reported by previous studies. Statistically significant differences in the odds ratios of concordance over time (baseline, 6-month, and 12-month follow-up) were found for marijuana and the combined category for PCP, amphetamine, and methamphetamine. Our findings suggest that oral fluid drug tests generally withstand community field assessments and result in relatively high levels of agreement for marijuana, cocaine, PCP, amphetamine, and methamphetamine use, when compared to self-report. Because of the ease of sample collection and low chance of adulteration, we conclude that saliva testing is a viable method for toxicological confirmation of substance use behavior in this setting.

Sex differences in the effect of bupropion and naltrexone combination on alcohol drinking in mice

A fixed dose combination of bupropion (BPP) and naltrexone (NTX), Contrave®, is an FDA approved pharmacotherapy for the treatment of obesity. A recent study found that combining BPP with low-dose NTX reduced alcohol drinking in alcohol-preferring male rats. To explore potential pharmacological effects of the BPP + NTX combination on alcohol drinking, both male and female C57Bl/6J mice were tested on one-week drinking-in-the dark (DID) and three-week intermittent access (IA) models. Neuronal proopiomelanocortin (POMC) enhancer knockout (nPE^-/-) mice with hypothalamic-specific deficiency of POMC, and its bioactive peptides melanocyte stimulating hormone and beta-endorphin, were used as a genetic control for the effects of the BPP + NTX. A single administration of BPP + NTX (10 mg/kg + 1 mg/kg) decreased alcohol intake after DID in C57Bl/6J males, but not females. Also in C57Bl/6J males, BPP + NTX reduced intake of the caloric reinforcer sucrose, but not the non-caloric reinforcer saccharin. In contrast, BPP + NTX had no effect on alcohol DID in nPE^-/- males. Pretreatment with the selective melanocortin 4 receptor (MC4R) antagonist HS014 reversed the anti-dipsogenic effect of BPP + NTX on alcohol DID in C57Bl/6J males. In the 3-week chronic IA model, single or repeated administrations for four days of BPP + NTX reduced alcohol intake and preference in C57Bl/6J males only. The behavioral measures observed in C57Bl/6J mice provide clear evidence that BPP + NTX profoundly reduced alcohol drinking in males, but the doses tested were not effective in females. Furthermore, our results suggest a hypothalamic POMC/MC4R-dependent mechanism for the observed BPP + NTX effects on alcohol drinking in male mice.

Molecular Imaging of Opioid and Dopamine Systems: Insights Into the Pharmacogenetics of Opioid Use Disorders

Opioid use in the United States has steadily risen since the 1990s, along with staggering increases in addiction and overdose fatalities. With this surge in prescription and illicit opioid abuse, it is paramount to understand the genetic risk factors and neuropsychological effects of opioid use disorder (OUD). Polymorphisms disrupting the opioid and dopamine systems have been associated with increased risk for developing substance use disorders. Molecular imaging studies have revealed how these polymorphisms impact the brain and contribute to cognitive and behavioral differences across individuals. Here, we review the current molecular imaging literature to assess how genetic variations in the opioid and dopamine systems affect function in the brain's reward, cognition, and stress pathways, potentially resulting in vulnerabilities to OUD. Continued research of the functional consequences of genetic variants and corresponding alterations in neural mechanisms will inform prevention and treatment of OUD.

PET imaging reveals lower kappa opioid receptor availability in alcoholics but no effect of age

Opioid receptors are implicated in alcoholism, other addictions, withdrawal, and depression, and are considered potential pharmacological targets for treatment. Our goal in the present study was to compare the availability of kappa opioid receptors (KOR) between an alcohol-dependent cohort (AD) and a healthy control cohort (HC). Sixty-four participants-36 AD and 28 HC-underwent PET scans with [11C]LY2795050, a selective kappa antagonist tracer. Partial-volume correction was applied to all PET data to correct for atrophy. Volume of distribution (VT) of the tracer was estimated regionally as a measure of KOR availability. VT values of AD versus HC were compared for 15 defined ROIs. Multivariate analysis showed a main effect of group on VT across these 15 ROIs. Post hoc tests showed that AD had significantly lower VT and thus a lower KOR availability than HC in amygdala and pallidum (corrected for multiple comparisons). Exploratory analysis of change in VT with age was conducted; VT was not found to vary significantly with age in any region. Our findings of lower VT in AD versus HC in multiple regions are in contrast to findings in the mu and delta opioid receptor systems of higher VT in AD versus HC. Although age-related decline in receptors has previously been observed in the mu opioid receptor system, we found that KOR availability does not change with age.

Naltrexone alters alcohol self-administration behaviors and hypothalamic-pituitary-adrenal axis activity in a sex-dependent manner in rats

BACKGROUND

The mu-opioid antagonist, naltrexone (NTX), is a FDA-approved treatment for alcohol use disorder (AUD); however, the data on whether it differentially affects males vs. females are mixed. NTX increases hypothalamic-pituitary-adrenal (HPA) axis activity that associates with subjective responses to alcohol and craving in individuals with AUD. The present study tested for sex differences in the ability of NTX to decrease appetitive and consummatory behaviors in rats in operant alcohol self-administration. Because the opioid system and HPA axis are sexually dimorphic, we examined NTX's effect on adrenocorticotropic hormone (ACTH) and corticosterone (CORT) levels.

METHODS

Male and female Sprague-Dawley rats (n's = 6-8) were trained to lever press for alcohol (10% v/v) under a fixed-ratio 2 schedule of reinforcement. NTX doses (0, 0.1-10 mg/kg) were assessed in tests conducted under a progressive ratio schedule of reinforcement. Separate groups of alcohol and water drinking rats (n's = 8) were used to assess NTX's (10 mg/kg) effects on HPA axis hormones.

RESULTS

NTX decreased consummatory behaviors for alcohol in a dose-related manner, but not appetitive behaviors in males. In females, NTX decreased appetitive behaviors for alcohol in a dose-dependent manner, but only decreased consummatory behaviors at the highest (10 mg/kg) NTX dose. NTX increased ACTH levels in alcohol drinking females in diestrus, but not in other groups. However, NTX increased CORT levels for longer durations in alcohol drinking males relative to alcohol drinking females in diestrus.

CONCLUSIONS

Our findings suggest that NTX selectively reduces consummatory behaviors for alcohol in males and appetitive behaviors in females, while also showing differential sex effects on HPA hormones.

The More Things Change, the More They Stay the Same: A Study to Evaluate Compliance With Inclusion and Assessment of Women and Minorities in Randomized Controlled Trials

PURPOSE

The National Institutes of Health (NIH) Revitalization Act of 1993 requires NIH-funded clinical trials to include women and minorities as participants and assess outcomes by sex and race or ethnicity. The objective of this study was to investigate current levels of compliance with these guidelines for inclusion, analysis, and reporting in NIH-funded randomized controlled trials (RCTs) and compare the results with those from 2009 and 2004, which the authors reported previously.

METHOD

The authors identified 782 RCTs published in 14 leading U.S. medical journals in 2015 with a PubMed search. Of those, 142 were the primary report of an NIH-funded RCT, conducted in the United States, and eligible for analysis. The authors reviewed abstract, text, and tables of each eligible study as well as any follow-up published commentary to determine compliance with NIH guidelines.

RESULTS

Thirty-five studies limited enrollment to one sex. The median enrollment of women in the remaining 107 studies was 46%, but 16 (15.0%) enrolled less than 30% women. Twenty-eight of the 107 (26%) reported at least one outcome by sex or explicitly included sex as a covariate in statistical analysis. Of the 142 studies, 19 (13.4%) analyzed or reported outcomes by race or ethnicity. There were no statistically significant changes in inclusion, analysis, or reporting by sex, race, or ethnicity compared with the previous studies.

CONCLUSIONS

NIH policies have not resulted in significant increases in reporting results by sex, race, or ethnicity. The authors recommend strong journal policies to increase compliance with NIH policies.

Enkephalin as a Pivotal Player in Neuroadaptations Related to Psychostimulant Addiction

Enkephalin expression is high in mesocorticolimbic areas associated with psychostimulant-induced behavioral and neurobiological effects, and may also modulate local neurotransmission in this circuit network. Psychostimulant drugs, like amphetamine and cocaine, significantly increase the content of enkephalin in these brain structures, but we do not yet understand the specific significance of this drug-induced adaptation. In this review, we summarize the neurochemical and molecular mechanism of psychostimulant-induced enkephalin activation in mesocorticolimbic brain areas, and the contribution of this opioid peptide in the pivotal neuroadaptations and long-term behavioral changes underlying psychostimulant addiction. There is evidence suggesting that adaptive changes in enkephalin content in the mesocorticolimbic circuit, induced by acute and chronic psychostimulant administration, may represent a key initial step in the long-term behavioral and neuronal plasticity induced by these drugs.

Sex and gender differences in substance use disorders

The gender gap in substance use disorders (SUDs), characterized by greater prevalence in men, is narrowing, highlighting the importance of understanding sex and gender differences in SUD etiology and maintenance. In this critical review, we provide an overview of sex/gender differences in the biology, epidemiology and treatment of SUDs. Biological sex differences are evident across an array of systems, including brain structure and function, endocrine function, and metabolic function. Gender (i.e., environmentally and socioculturally defined roles for men and women) also contributes to the initiation and course of substance use and SUDs. Adverse medical, psychiatric, and functional consequences associated with SUDs are often more severe in women. However, men and women do not substantively differ with respect to SUD treatment outcomes. Although several trends are beginning to emerge in the literature, findings on sex and gender differences in SUDs are complicated by the interacting contributions of biological and environmental factors. Future research is needed to further elucidate sex and gender differences, especially focusing on hormonal factors in SUD course and treatment outcomes; research translating findings between animal and human models; and gender differences in understudied populations, such as those with co-occurring psychiatric disorders and gender-specific populations, such as pregnant women.

Atomoxetine in abstinent cocaine users: Sex differences

Data presented are from a sex-differences secondary analysis of a human laboratory investigation of single doses of atomoxetine (40 mg and 80 mg) versus placebo in abstinent individuals with cocaine use disorders (CUD). Subjective drug effects, cognitive performance and cardiovascular measures were assessed. The primary atomoxetine dose analyses (which do not consider sex as a factor) are reported in full elsewhere (DeVito et al., 2017) [1].

Fatal and non-fatal opioid overdose in opioid dependent patients treated with methadone, buprenorphine or implant naltrexone

BACKGROUND

Illicit opioid use is associated with high rates of fatal and non-fatal opioid overdose. This study aims to compare rates of fatal and serious but non-fatal opioid overdose in opioid dependent patients treated with methadone, buprenorphine or implant naltrexone, and to identify risk factors for fatal opioid overdose.

METHODS

Opioid dependent patients treated with methadone (n=3515), buprenorphine (n=3250) or implant naltrexone (n=1461) in Western Australia for the first time between 2001 and 2010, were matched against state mortality and hospital data. Rates of fatal and non-fatal serious opioid overdoses were calculated and compared for the three treatments. Risk factors associated with fatal opioid overdose were examined using multivariate cox proportional hazard models.

RESULTS

No significant difference was observed between the three groups in terms of crude rates of fatal or non-fatal opioid overdoses. During the first 28days of treatment, rates of non-fatal opioid overdose were high in all three groups, as were fatal opioid overdoses in patients treated with methadone. However, no fatal opioid overdoses were observed in buprenorphine or naltrexone patients during this period. Following the first 28 days, buprenorphine was shown to be protective, particularly in terms of non-fatal opioid overdoses. After the cessation of treatment, rates of fatal and non-fatal opioid overdoses were similar between the groups, with the exception of lower rates of non-fatal opioid overdose in the naltrexone treated patients compared with the methadone treated patients. After the commencement of treatment, gender, and hospitalisations with a diagnosis of opioid poisoning, cardiovascular or mental health problems were significant predictors of subsequent fatal opioid overdose.

CONCLUSIONS

Rates of fatal and non-fatal opioid overdose were not significantly different in patients treated with methadone, buprenorphine or implant naltrexone. Gender and prior cause-specific hospitalisations can be used to identify patients at a high risk of fatal opioid overdose.

A Systematic Review of Naltrexone for Attenuating Alcohol Consumption in Women with Alcohol Use Disorders

Several clinical trials have evaluated naltrexone as a treatment for alcohol use disorders (AUDs), but few have focused on women. The aim of this review was to systematically review and summarize the evidence regarding the impact of naltrexone compared to placebo for attenuating alcohol consumption in women with an AUD. A systematic review was conducted using PubMed, Cochrane, Web of Science, CINAHL, and Alcohol Studies Database to identify relevant peer-reviewed randomized controlled trials (RCTs) published between January 1990 and August 2016. Seven published trials have evaluated the impact of naltrexone on drinking outcomes in women distinct from men; 903 alcohol-dependent or heavy drinking women were randomized to receive once daily oral or depot (injectable) naltrexone or placebo with/without behavioral intervention. Two studies examining the quantity of drinks per day observed trends toward reduction in drinking quantity among women who received naltrexone versus placebo. The 4 studies examining the frequency of drinking had mixed results, with 1 study showing a trend that favored naltrexone, 2 showing a trend that favored placebo, and 1 that showed no difference. Two of the 3 studies examining time to relapse observed trends that tended to favor naltrexone for time to any drinking and time to heavy drinking among women who received naltrexone versus placebo. While the growing body of evidence suggests a variety of approaches to treat AUD, the impact of naltrexone to combat AUD in women is understudied. Taken together, the results suggest that naltrexone may lead to modest reductions in quantity of drinking and time to relapse, but not on the frequency of drinking in women. Future research should incorporate sophisticated study designs that examine gender differences and treatment effectiveness among those diagnosed with an AUD and present data separately for men and women.

High-Dose Naltrexone Treatment and Gender in Alcohol Dependence

OBJECTIVES

Little is known about whether safety and effectiveness of high-dose naltrexone (150 mg/d) are different in alcohol-dependent women and men. This study investigated sex differences in safety and treatment outcomes in alcohol-dependent women and men on high-dose naltrexone (150 mg/d).

METHODS

In this exploratory study, safety and effectiveness of high-dose naltrexone (150 mg/d) were examined in men and women with alcohol dependence (n = 24; 11 men and 13 women) treated in an 8-week outpatient setting.

RESULTS

Women and men had similar dropout rates, adverse effects, tolerability, and hepatic function during high-dose naltrexone treatment (150 mg/d). Drinking outcomes were significantly improved in both women and men, but no sex differences were found.

CONCLUSIONS

High-dose naltrexone seems to be well tolerated, safe, and effective in both men and women with alcohol dependence in this small study. Given the small sample size of the current study, our results cannot be considered definitive, and larger trials with longer durations are needed to confirm these findings.

PET imaging reveals sex differences in kappa opioid receptor availability in humans, in vivo

Opioid receptors may play critical roles in alcoholism and other addictions, addiction withdrawal, and depression and are considered pharmacological targets for treatment of these conditions. Sex differences have been demonstrated in mu (MOR) and delta (DOR) opioid receptors in humans, in vivo. In addition, sex differences have been observed in efficacy of treatment targeting kappa opioid receptors (KOR). Our goal in the present study was to compare the availability of KOR (1) between healthy control (HC) men and women. Twenty-seven subjects-18 males (M) and 9 females (F)-underwent PET scans with [(11)C] LY2795050, a selective kappa antagonist tracer. Partial volume correction was applied to all PET data. Volume of distribution (V T) of the tracer was estimated regionally as well as at the voxel level. V T values of males versus females were compared for 19 defined ROIs. Results at the regional and voxel levels were consistent. Males had significantly higher V T and thus a higher KOR availability than women in multiple brain regions. To our knowledge, this is the first report of sex differences in the KOR system in humans, in vivo. These findings could have implications for the treatment of pain with kappa opioid analgesics. The results may also have an impact on the diagnosis and treatment of addictive and other disorders.

Brain Activity During Cocaine Craving and Gambling Urges: An fMRI Study

Although craving states are important to both cocaine dependence (CD) and pathological gambling (PG), few studies have directly investigated neurobiological similarities and differences in craving between these disorders. We used functional magnetic resonance imaging (fMRI) to assess brain activity in 103 participants (30 CD, 28 PG, and 45 controls) while they watched videos depicting cocaine, gambling, and sad scenarios to investigate the neural correlates of craving. We observed a three-way urge type × video type × diagnostic group interaction in self-reported craving, with CD participants reporting strong cocaine cravings to cocaine videos, and PG participants reporting strong gambling urges to gambling videos. Neuroimaging data revealed a diagnostic group × video interaction in anterior cingulate cortex/ventromedial prefrontal cortex (mPFC), activating predominantly to cocaine videos in CD participants, and a more dorsal mPFC region that was most strongly activated for cocaine videos in CD participants, gambling videos in PG participants, and sad videos in control participants. Gender × diagnosis × video interactions identified dorsal mPFC and a region in posterior insula/caudate in which female but not male PG participants showed increased responses to gambling videos. Findings illustrate both similarities and differences in the neural correlates of drug cravings and gambling urges in CD and PG. Future studies should investigate diagnostic- and gender-specific therapies targeting the neural systems implicated in craving/urge states in addictions.

Case Report: Internet Gaming Disorder Associated With Pornography Use

Internet gaming disorder (IGD) is not currently a recognized diagnosis in the Diagnostic and Statistical Manual for Mental Disorders-5 (DSM-5). However, IGD has been noted to warrant further research for possible future inclusion in the DSM. In many ways, IGD strongly resembles substance and gambling addictions. Such characteristics include tolerance, withdrawal, and social and occupational neglect resulting from increased time invested in video game use and acquisition. The use of similar or closely related media is also seen, which mirrors the natural course of substance and gambling addictions. We present a case of a 22-year-old man who exhibited IGD and problems associated with pornography use. This case report exemplifies the sequelae of IGD. Our paper also reviews the possible mechanisms of behavioral addiction, as well as the status of IGD as a potential subcategory of behavioral addiction. Additional research is needed to determine if IGD co-occurs with problematic use of pornography.

Alcohol preferring (P) rats as a model for examining sex differences in alcohol use disorder and its treatment

RATIONALE

Despite epidemiological and clinical data indicating marked gender differences in alcohol use disorders (AUDs), few preclinical studies have examined sex differences in animal models of AUDs.

OBJECTIVE

The purpose of this study was to first characterize sex differences in ethanol consumption and reinforcement in an alcohol preferring (P) rat model of alcoholism, then use this model to screen pharmacological treatments for sex-specific effects.

METHODS

Ethanol consumption was first assessed in male and female P rats under a three-bottle free-choice procedure. Next, ethanol's reinforcing effects were assessed under a fixed-ratio 1 (FR1) schedule followed by a progressive-ratio (PR) schedule. Finally, the effects of two pharmacological treatments for AUDs, naltrexone (1mg/kg) and topiramate (10 or 20mg/kg), alone and in combination, were tested for sex-specific differences in their efficacy at reducing ethanol's reinforcing effects.

RESULTS

Although females initially had higher consumption of and preference for ethanol, male rats increased their consumption and preference over time and rapidly became equal to females. Following prolonged 24-hour/day access, males and females self-administered similar levels of ethanol under FR1 and PR schedules. In response to pharmacological treatment, we observed some sex differences and similarities, most notably, a more robust effect of the combination of naltrexone and topiramate in males as compared to females.

CONCLUSIONS

This model of selectively bred P rats may be useful for understanding sex differences in AUDs and related behavior and their underlying neurobiological mechanisms and treatment.

Internet addiction disorder and problematic use of Google Glass™ in patient treated at a residential substance abuse treatment program

INTRODUCTION

Internet addiction disorder (IAD) is characterized by the problematic use of online video games, computer use, and mobile handheld devices. While not officially a clinical diagnosis according to the most recent version of the Diagnostic and Statistical Manual of Mental Disorders (DSM), individuals with IAD manifest severe emotional, social, and mental dysfunction in multiple areas of daily activities due to their problematic use of technology and the internet.

METHOD

We report a 31year-old man who exhibited problematic use of Google Glass™. The patient has a history of a mood disorder most consistent with a substance induced hypomania overlaying a depressive disorder, anxiety disorder with characteristics of social phobia and obsessive compulsive disorder, and severe alcohol and tobacco use disorders.

RESULTS

During his residential treatment program at the Navy's Substance Abuse and Recovery Program (SARP) for alcohol use disorder, it was noted that the patient exhibited significant frustration and irritability related to not being able to use his Google Glass™. The patient exhibited a notable, nearly involuntary movement of the right hand up to his temple area and tapping it with his forefinger. He reported that if he had been prevented from wearing the device while at work, he would become extremely irritable and argumentative.

CONCLUSIONS

Over the course of his 35-day residential treatment, the patient noted a reduction in irritability, reduction in motor movements to his temple to turn on the device, and improvements in his short-term memory and clarity of thought processes. He continued to intermittently experience dreams as if looking through the device. To our knowledge, this is the first reported case of IAD involving problematic use of Google Glass™.

Gender differences in clinical outcomes for cocaine dependence: randomized clinical trials of behavioral therapy and disulfiram

BACKGROUND

Despite extensive research on gender differences in addiction, there are relatively few published reports comparing treatment outcomes for women versus men based on evidence-based treatments evaluated in randomized clinical trials.

METHODS

An aggregate sample comprised of data from five randomized clinical trials of treatment for cocaine dependence (N = 434) was evaluated for gender differences in clinical outcomes. Secondary analyses compared gender differences in outcome by medication condition (disulfiram versus no medication) and across multiple behavioral treatment conditions.

RESULTS

Women, compared with men, had poorer treatment outcomes on multiple measures of cocaine use during treatment and at post-treatment follow-up. These results appear to be primarily accounted for by disulfiram being less effective in women compared with men. There was no evidence of meaningful gender differences in outcome as a function of the behavioral therapies evaluated.

CONCLUSIONS

These findings suggest that women and men may benefit to similar degrees from some empirically validated behavioral treatments for addiction. Conversely, some addiction pharmacotherapies, such as disulfiram, may be associated with poorer outcomes among women relative to men and point to the need for careful assessment of pharmacological treatments in both sexes prior to widespread clinical implementation.

A pilot trial of injectable, extended-release naltrexone for the treatment of co-occurring cocaine and alcohol dependence

BACKGROUND

There is a high co-occurrence of cocaine and alcohol use disorders, and patients with both of these problems are difficult to treat. There is a reasonable rationale and some empirical data to justify a pilot trial of an injectable, extended-release formulation of naltrexone for treating co-occurring cocaine and alcohol addiction.

METHODS

Eighty cocaine (n = 80) and alcohol dependent, treatment-seeking subjects were randomly assigned to receive either two monthly extended-release injections of naltrexone or two matching placebo injections in an 8-week clinical trial, with weekly medical management plus cognitive behavioral therapy visits.

RESULTS

No differences in reduction in cocaine or alcohol use were observed between the injectable naltrexone and placebo groups during the 8-week trial.

CONCLUSIONS

Injectable extended-release naltrexone, while an ideal method for ensuring medication adherence in these traditionally hard-to-treat patients, did not result in any measurable reduction in cocaine or alcohol use over the course of 8 weeks of treatment.

Genders and the concurrent use of cocaine and alcohol: Pharmacological aspects

AIMS

Gender-related differences in the pharmacological effects of addictive drug are an emerging issue. This review examines gender differences in both pharmacokinetic and pharmacodynamic aspects of alcohol and cocaine intake since they cause complex pharmacological interactions, not least the formation of the active metabolite cocaethylene.

METHODS

The MEDLINE database was searched from 1990 to 2014 in order to find articles related to gender differences in alcohol, cocaine and cocaethylene pharmacokinetics and pharmacodynamics.

RESULTS

Besides the well known gender differences in alcohol pharmacokinetics, women appear more susceptible to alcohol-mediated brain damage and seem to suffer more than men the acute effects of alcohol on hepatic and gonadal hormones. No significant gender differences have been found in the pharmacokinetics of cocaine taken alone; yet, in women pharmacological sensitivity to the drug seems to vary in relation to menstrual cycle; moreover, progesterone attenuates subjective effects of cocaine in women. Higher ratings at a subjective measure of mental/physical well-being have been observed in women when given cocaine and alcohol, alone or in combination. Finally, among subjects dependent on both alcohol and cocaine, men only benefit from naltrexone, whereas women used more cocaine during the trial and were less compliant to therapy than men.

CONCLUSIONS

The observed subtle gender differences in the pharmacokinetics and pharmacodynamics of both alcohol and cocaine may have no subtle influence on the natural history of the co-abuse of the two drugs by women.

Mixed κ/μ partial opioid agonists as potential treatments for cocaine dependence

Cocaine use activates the dopamine reward pathway, leading to the reinforcing effects of dopamine. There is no FDA-approved medication for treating cocaine dependence. Opioid agonists and antagonists have been approved for treating opioid and alcohol dependence. Agonists that activate the μ opioid receptor increase dopamine levels in the nucleus accumbens, while μ receptor antagonists decrease dopamine levels by blocking the effects of endogenous opioid peptides. Activation of the κ opioid receptor decreases dopamine levels and leads to dysphoria. In contrast, inhibition of the κ opioid receptor decreases dopamine levels in the nucleus accumbens. Antagonists acting at the κ receptor reduce stress-mediated behaviors and anxiety. Mixed partial μ/κ agonists have the potential of striking a balance between dopamine levels and attenuating relapse to cocaine. The pharmacological properties of mixed μ/κ opioid receptor agonists will be discussed and results from clinical and preclinical studies will be presented. Results from studies with some of the classical benzomorphans and morphinans will be presented as they lay the foundation for structure-activity relationships. Recent results with other partial opioid agonists, including buprenorphine derivatives and the mixed μ/κ peptide CJ-15,208, will be discussed. The behavioral effects of the mixed μ/κ MCL-741, an aminothiazolomorphinan, in attenuating cocaine-induced locomotor activity will be presented. While not a mixed μ/κ opioid, results obtained with GSK1521498, a μ receptor inverse agonist, will be discussed. Preclinical strategies and successes will lay the groundwork for the further development of mixed μ/κ opioid receptor agonists to treat cocaine dependence.

Placebo group improvement in trials of pharmacotherapies for alcohol use disorders: a multivariate meta-analysis examining change over time

OBJECTIVE

Placebo group improvement in pharmacotherapy trials has been increasing over time across several pharmacological treatment areas. However, it is unknown to what degree increasing improvement has occurred in pharmacotherapy trials for alcohol use disorders or what factors may account for placebo group improvement. This meta-analysis of 47 alcohol pharmacotherapy trials evaluated (1) the magnitude of placebo group improvement, (2) the extent to which placebo group improvement has been increasing over time, and (3) several potential moderators that might account for variation in placebo group improvement.

METHOD

Random-effects univariate and multivariate analyses were conducted that examined the magnitude of placebo group improvement in the 47 studies and several potential moderators of improvement: (a) publication year, (b) country in which the study was conducted, (c) outcome data source/type, (d) number of placebo administrations, (e) overall severity of study participants, and (f) additional psychosocial treatment.

RESULTS

Substantial placebo group improvement was found overall and improvement was larger in more recent studies. Greater improvement was found on moderately subjective outcomes, with more frequent administrations of the placebo, and in studies with greater participant severity of illness. However, even after controlling for these moderators, placebo group improvement remained significant, as did placebo group improvement over time.

CONCLUSIONS

Similar to previous pharmacotherapy placebo research, substantial pretest to posttest placebo group improvement has occurred in alcohol pharmacotherapy trials, an effect that has been increasing over time. However, several plausible moderator variables were not able to explain why placebo group improvement has been increasing over time.

The placebo effect in clinical trials for alcohol dependence: an exploratory analysis of 51 naltrexone and acamprosate studies

BACKGROUND

The placebo effect often undermines efforts to determine treatment effectiveness in clinical trials. A significant placebo response occurs in alcohol trials, but it is not well understood. The purpose of this study was to characterize the placebo response across multiple naltrexone and acamprosate studies.

METHODS

Fifty-one trials, 3 with a naltrexone and an acamprosate arm, 31 with at least 1 naltrexone arm, and 17 with at least 1 acamprosate arm, were identified from Cochrane reviews and PubMed search. To be included in this study, patients had to be at least 18 years old, abstinent from alcohol before randomization, and meet a diagnosis of alcohol dependence. Pearson correlation coefficients (rp ) and simple linear regression were used to describe the strength of linear relationships between placebo response and treatment effect size. Spearman's rank correlation coefficients (rs ) were used to examine the strength of associations between study characteristics and placebo response.

RESULTS

For the end point measures of percent days abstinent and total abstinence, a negative relationship was evident between placebo response and treatment effect size in the naltrexone trials (rp  = -0.55, p < 0.01 and rp  = -0.20, p = 0.35, respectively) as well as in the acamprosate trials (rp  = -0.45, p = 0.09 and rp  = -0.56, p = 0.01, respectively). The placebo response for percent days abstinent was negatively correlated with mean age of participants (rs  = -0.42, p = 0.05) across naltrexone trials and positively correlated with publication year (rs  = 0.57, p = 0.03) across acamprosate trials. However, these 2 study characteristics were not significantly correlated with treatment effect size.

CONCLUSIONS

The placebo response varied considerably across trials and was negatively correlated with the treatment effect size. Additional studies are required to fully understand the complex nature of the placebo response and to evaluate approaches to minimize its effects.

The μ-opioid receptor and treatment response to naltrexone

AIMS

To evaluate the pharmacogenetic evidence relating to the use of opioid antagonists (in particular naltrexone) in treating patients with alcohol abuse problems.

METHODS

Narrative review of pre-clinical and clinical published research regarding genetic modulation of psychotropic effects produced by alcohol and the therapeutic effects of opioid antagonists.

RESULTS

Alcohol activates brain reward pathways, leading to positive reinforcement of alcohol seeking and consumption. Thus, the underlying biological mechanisms may be targets for treatment, particularly in the early stages of addiction development. Alcohol reward is in part mediated by endogenous opioids. A single-nucleotide polymorphism (SNP) within the OPRM1 gene, A118G, leading to an amino acid change (Asn40Asp) in the extracellular portion of the receptor, has been implicated in alcoholism as well as in drug addiction, pain sensitivity and stress response, and in animal and human studies relates to the alcohol-dependent phenotype as well as to the treatment response to the µ-opioid antagonist naltrexone.

CONCLUSION

The effect size reported in naltrexone clinical studies is often small, which may be due to heterogeneity among patients. Pharmacogenetic approaches may help guide us in the search for the appropriate treatment optimal for one patient's need.