Exercise as a potential treatment for drug abuse: evidence from preclinical studies

Possible role of exercise therapy on depression: Effector neurotransmitters as key players

About 280 million people suffer from depression as the most common neurological disorder and the most common cause of death worldwide. Exercise with serotonin released in the brain by the 5-HT3-IGF-1 mechanism can lead to antidepressant effects. Swimming exercise has antidepressant effects by increasing the sensitivity of serotonin 5-HT2 receptors and postsynaptic 5-HT1A receptors, increasing 5-HT and 5HIAA levels, increasing TPH and serotonin, and decreasing inflammatory levels of IFN-γ and TNF-α. Anaerobic and aerobic exercises increase beta-endorphin, enkephalin, and dynorphin and have antidepressant effects. Exercise by increasing dopamine, D1R, and D2R leads to the expression of BDNF and activation of TrkB and has antidepressant behavior. Exercise leads to a significant increase in GABAAR (γ2 and α2 subunits) and reduces neurodegenerative disorders caused by GABA imbalance through anti-inflammatory pathways. By increasing glutamate and PGC1α and reducing glutamatergic neurotoxicity, exercise enhances neurogenesis and synaptogenesis and prevents neurodegeneration and the onset of depression. Irisin release during exercise shows an important role in depression by increasing dopamine, BDNF, NGF, and IGF-1 and decreasing inflammatory mediators such as IL-6 and IL-1β. In addition, exercise-induced orexin and NPY can increase hippocampal neurogenesis and relieve depression. After exercise, the tryptophan to large neutral amino acids (TRP/LNAA) ratio and the tryptophan to branched-chain amino acids (BCAA) ratio increase, which may have antidepressant effects. The expression of M5 receptor and nAChR α7 increases after exercise and significantly increases dopamine and acetylcholine and ameliorates depression. It appears that during exercise, muscarinic receptors can reduce depression through dopamine in the absence of acetylcholine. Therefore, exercise can be used to reduce depression by affecting neurotransmitters, neuromodulators, cytokines, and/or neurotrophins.

Sweating for Sobriety: Exploring the Relationship Between Exercise Engagement and Substance Use Disorders

Despite various interventions available for substance use disorders, relapse rates remain substantial and, therefore, alternative strategies for attenuating dependence are needed. This study examined the associations between exercise frequency, illicit substance use, and dependence severity among a large sample of people who use drugs. The study utilized data from the Global Drug Survey 2018 (N = 57,110) to investigate the relationship between exercise frequency, illicit substance use, and substance dependence severity. Binomial regressions were employed to examine the relationship between exercise and SDS scores for 9 drugs. Greater exercise frequency correlated with reduced severity of substance dependence for specific drugs: cannabis (χ2 = 14.75, p < .001), MDMA (χ2 = 4.73, p = .029), cocaine (χ2 = 8.37, p = .015), amphetamine powder (χ2 = 6.39, p = .041), and methamphetamine (χ2 = 15.17, p < .001). These findings suggest a potential link between exercise and reduced substance use dependency. Further research is needed to understand the complex dynamics between exercise and substance use, considering potential bidirectional relationships and concurrent factors.

High intensity interval training exercise increases dopamine D2 levels and modulates brain dopamine signaling

Background

Previous research has outlined the health benefits of exercise including its therapeutic potential for substance use disorders (SUD). These data have already been utilized and it is now common to find exercise as part of SUD treatment and relapse prevention programs. However, we need to better understand different exercise regimens and determine which would be the most beneficial for SUDs. Recently, high intensity interval training (HIIT) has gained attention in comparison with aerobic and resistance exercise. Little is known regarding the neurobiological mechanisms of HIIT, including its effects on dopamine signaling and receptor levels in the brain. The present study examined the effects of chronic HIIT exercise on dopamine signaling as measured by dopamine type 1-like receptor (D1R)-like, dopamine type 2-like receptor (D2R)-like, and tyrosine hydroxylase (TH) quantification in the brains of male and female rats as measured by [3H] SCH 23390 and [3H] spiperone autoradiography, and TH-immunoreactive optical density values.

Methods

Rats were separated in two groups: sedentary and HIIT exercise. Exercise was on a treadmill for 30 min daily (10 3 min cycles) for six weeks with progressive speed increased up to 0.8 mph (21.5 m/min).

Results

Results showed for D2R-like binding, a significant effect across the ventral caudate putamen (V CPU) between sexes, such that mean D2R-like binding was 14% greater for males than females. In the nucleus accumbens shell (Nac Shell), the HIIT Exercise rats showed 16% greater D2R-like binding as compared to the sedentary rats. No significant effects of HIIT exercise were found across groups for brain D1R-like binding levels or TH expression.

Conclusion

These results suggest that HIIT exercise can modulate dopamine signaling by way of increased D2R. These findings support the premise that HIIT exercise plays an important role in dopamine signaling and, may provide a potential mechanism for how HIIT exercise can impact the brain and behavior.

Behaviour change techniques in physical activity-focused interventions for young people at risk of problematic substance use: A systematic review and meta-analysis

AIM

This systematic review investigates behaviour change techniques in interventions promoting physical activity for young people aged 12-25 years at heightened risk of problematic substance use, and the effect of these techniques on physical activity participation and substance use outcomes.

METHODS

Four databases (PsycINFO, CINAHL, SPORTDiscus and Medline) were searched between November 2020 and November 2022 for randomized and non-randomized controlled studies according to inclusion criteria. Meta-analyses were calculated using weighted, standardized averages of effect sizes (Hedges' g).

RESULTS

Twenty-eight studies were included, 14 studies in the meta-analysis (intervention n = 1328; control n = 845). Reported BCTs included behavioural instructions, social comparison and goal setting. There was a significant effect of behaviour change techniques on combined substance use outcomes, such as cravings and consumption, for interventions reporting multiple behaviour change techniques (g = -0.33, p < .001, 95% CI [-0.50,-0.16]) or one single behaviour change technique (g = -1.84, p < .001, 95% CI [-2.89,-0.8]). Limitations include unexplained variance and limited reporting of relevant behaviour change technique data in the included studies.

CONCLUSION

The results indicate that using behaviour change techniques in interventions that promote physical activity for young people has an effect on substance use. Further research needs to be completed comparing the impact of the number and type of behaviour change technique, and improved reporting of intervention content is required.

The role of Neurochemicals, Stress Hormones and Immune System in the Positive Feedback Loops between Diabetes, Obesity and Depression

Type 2 diabetes mellitus (T2DM) and depression are significant public health and socioeconomic issues. They commonly co-occur, with T2DM occurring in 11.3% of the US population, while depression has a prevalence of about 9%, with higher rates among youths. Approximately 31% of patients with T2DM suffer from depressive symptoms, with 11.4% having major depressive disorders, which is twice as high as the prevalence of depression in patients without T2DM. Additionally, over 80% of people with T2DM are overweight or obese. This review describes how T2DM and depression can enhance one another, using the same molecular pathways, by synergistically altering the brain's structure and function and reducing the reward obtained from eating. In this article, we reviewed the evidence that eating, especially high-caloric foods, stimulates the limbic system, initiating Reward Deficiency Syndrome. Analogous to other addictive behaviors, neurochemical changes in those with depression and/or T2DM are thought to cause individuals to increase their food intake to obtain the same reward leading to binge eating, weight gain and obesity. Treating the symptoms of T2DM, such as lowering HbA1c, without addressing the underlying pathways has little chance of eliminating the disease. Targeting the immune system, stress circuit, melatonin, and other alterations may be more effective.

The efficacy of exercise interventions for all types of inpatients across mental health settings: A systematic review and meta-analysis of 47 studies

This systematic review and meta-analysis investigated the benefits, safety and adherence of exercise interventions delivered in inpatient mental health settings, quantified the number of exercise trials that provided support to maintain engagement in exercise post-discharge, and reported patient feedback towards exercise interventions. Major databases were searched from inception to 22.06.2022 for intervention studies investigating exercise in mental health inpatient settings. Study quality was assessed using Cochrane and ROBINS-1 checklists. Fifty-six papers were included from 47 trials (including 34 RCTs), bias was high. Exercise improved depression (Standardised mean difference = -0.416; 95% Confidence interval -0.787 to -0.045, N = 15) compared to non-exercise comparators amongst people with a range of mental illnesses, with further (albeit limited) evidence suggesting a role of exercise in cardiorespiratory fitness and various other physical health parameters and ameliorating psychiatric symptoms. No serious exercise-related adverse events were noted, attendance was ≥80% in most trials, and exercise was perceived as enjoyable and useful. Five trials offered patients post-discharge support to continue exercise, with varying success. In conclusion, exercise interventions may have therapeutic benefits in inpatient mental health settings. More high-quality trials are needed to determine optimal parameters, and future research should investigate systems to support patients to maintain exercise engagement once discharged.

Intervention Effect of Aerobic Exercise on Physical Fitness, Emotional State and Mental Health of Drug Addicts: A Systematic Review and Meta-Analysis

This study aims to discuss evidence for the efficacy of aerobic exercise in reducing drug addiction and improving the physical and mental health of drug addicts. We systematically searched several online databases as of the end of September 2022, including PubMed, EMBASE, the Cochrane Library, Web of Science, Scopus, Science Direct, CNKI, VIP, CBM, and Wanfang. All articles were identified, screened and included according to the inclusion or exclusion criteria. The Cochrane Handbook for Systematic Reviews of Interventions was used as a criterion for assessing the methodological quality of included studies. Random and fixed effects models were used for the analysis of standard mean differences (SMD) or mean differences (MD) with their 95% confidence intervals (CI). A total of 27 studies involving 2022 drug addicts were finally included in the analysis. The results of the meta-analysis showed that aerobic exercise could improve the physical fitness [body fat percentage: MD = -0.74, 95%CI (-1.40, -0.08), vital capacity: MD = 213.79, 95%CI (46.28, 381.29), muscle force: MD = 1.21, 95%CI (0.34, 2.08), flexibility: MD = 4.61, 95%CI (2.98, 6.25), balance: MD = 9.95, 95%CI (6.29, 13.62)], regulate the systolic blood pressure: MD = -4.38, 95%CI (-7.08, -1.68), diastolic blood pressure: MD = -2.66, 95% CI (-3.82, -1.51), beats per minute: MD =-1.92, 95%CI (-3.19, -0.65); emotional state [anxiety: MD = -4.56, 95% CI (-5.67, -3.45), depression: MD = -3.28, 95%CI (-5.16, -1.39), drug craving: SMD= -1.68,95% CI(-2.56, -0.80)], and promote the mental health [anxiety: MD = -0.22, 95%CI (-0.33, -0.11), obsessive-compulsive: MD = -0.26, 95%CI (-0.50, -0.03), somatization: MD = -0.21, 95%CI (-0.27, -0.14), depression: MD = -0.21, 95%CI (-0.28, -0.15), psychoticcism: MD = -0.12, 95%CI (-0.18, -0.06), phobic anxiety: MD = -0.11, 95%CI (-0.16, -0.07), paranoid ideation: MD = -0.09, 95%CI (-0.15, -0.02), interpersonal sensitivity: MD = -0.16, 95%CI (-0.22, -0.10), hostility: MD = -0.12, 95%CI (-0.18, -0.05)], with statistically significant differences(p < 0.05)] of drug addicts. Thus, aerobic exercise could effectively improve the physical fitness, emotional state and mental health of drug addicts, and reduce their drug addiction. For clinical practitioners and researchers, this study could provide more reliable evidence for addiction treatment.

Utilizing Soccer for Delivery of HIV and Substance Use Prevention for Young South African Men: 6-Month Outcomes of a Cluster Randomized Controlled Trial

Young men in South Africa face the intersecting epidemics of HIV, substance use and endemic poverty. We tested the effectiveness of a behavioral intervention using soccer training to reduce the cluster of risks associated with HIV and substance use. This cluster randomized controlled trial was conducted with men aged 18-29 years old in 27 neighborhoods in the townships of Cape Town, South Africa. Neighborhoods were randomized to receive for 6 months either: (1) Soccer League (SL; n = 18 neighborhoods, n = 778 men) who attended soccer three times weekly (72 sessions; 94% uptake, 45.5% weekly attendance rate), combined with an HIV/substance use, cognitive-behavioral intervention; or (2) a Control Condition (CC; n = 9; 415 men) who received educational materials and referrals at 3 month intervals. The primary outcome was the number of significant changes in a cluster of outcomes including HIV-related risks, substance abuse, employment/income, mental health, violence, and community engagement. There was only one significant difference on the rapid diagnostic tests for mandrax at 6 months, an insufficient number of changes to indicate a successful intervention. A group-based behavioral intervention was ineffective in addressing multiple risk behaviors among at-risk young men, similar to the findings of several recent soccer-related interventions. Early adulthood may be too late to alter well-established patterns of risk behaviors.Clinical Trial Registration This trial was prospectively registered on 24 November 2014 with ClinicalTrials.gov NCT02358226.

Impact of Calorie-Restricted Cafeteria Diet and Treadmill Exercise on Sweet Taste in Diet-Induced Obese Female and Male Rats

The goal of the present study was to evaluate the sweet taste function in obese rats fed with a 30% calorie-restricted cafeteria diet (CAFR) and/or subjected to moderate treadmill exercise (12-17 m/min, 35 min, 5 days per week) for 9 weeks. A two-bottle preference test, a taste reactivity test, and a brief-access licking test were carried out when animals were aged 21 weeks; biometric and metabolic parameters were also measured along the interventions. Two separate experiments for females and males were performed. Behaviorally, CAF diet decreased sucrose intake and preference, as well as perceived palatability, in both sexes and decreased hedonic responses in males. Compared to the CAF diet, CAFR exerted a corrective effect on sweet taste variables in females by increasing sucrose intake in the preference test and licking responses, while exercise decreased sucrose intake in both sexes and licking responses in females. As expected, CAF diet increased body weight and Lee index and worsened the metabolic profile in both sexes, whereas CAFR diet ameliorated these effects mainly in females. Exercise had no noticeable effects on these parameters. We conclude that CAF diet might diminish appetitive behavior toward sucrose in both sexes, and that this effect could be partially reverted by CAFR diet in females only, while exercise might exert protective effects against overconsumption of sucrose in both sexes.

Reducing short- and long-term cocaine craving with voluntary exercise in male rats

BACKGROUND

In a previous study in female rats, voluntary wheel running attenuated incubation of cocaine craving after 30 but not 3 days (Zlebnik and Carroll Zlebnik and Carroll, Psychopharmacology 232:3507-3413, 2015). The present study in male rats, using the same procedure, showed that wheel running reduced incubated craving after both 30 and 3 days of abstinence.

METHODS

Male rats self-administered i.v. cocaine (0.4 mg/kg) during 6-h sessions for 10 days. They were then moved from the operant chamber to a home cage with an attached running wheel or stationary wheel, for 6 h daily for a 3- or 30-day period when cocaine craving was hypothesized to incubate. Rats were then returned to the operant chamber for a 30-min test of cocaine seeking, or "craving," indicated by responses on the former "drug" lever was formerly associated with drug stimulus lights and responses (vs. no drug stimuli), and lever responding was compared to responses on the "inactive" that was illuminated and counted lever pressing.

RESULTS

Mean wheel revolutions were similar across the 3- and 30-day incubation groups, when both groups of rats were given access to wheel running vs. access to a stationary wheel in controls. Subsequently, when rats were tested in the operant chamber for "relapse" responding (drug-lever responding) on the lever formerly associated with drug access, cocaine craving was reduced by recent running wheel access (vs. stationary wheel access) in both the 3- and 30-day wheel exposure groups.

CONCLUSION

Voluntary, self-initiated, and self-sustained physical exercise reduced cocaine craving after short- (3 days) and long-term (30 days) abstinence periods in male rats that previously self-administered cocaine. This was contrasted with reduction of cocaine seeking in females after 30-day, but not 3-day, incubation periods under the wheel running vs. stationary wheel conditions in a previous study (Zlebnik and Carroll Zlebnik and Carroll, Psychopharmacology 232:3507-3413, 2015). These initial findings suggest males may be more sensitive to incubated craving for cocaine than females.

Epidemiology of tobacco use and nicotine dependence in truck drivers

OBJECTIVE

To investigate the epidemiology of tobacco use and nicotine dependence in a sample of truck drivers in Brazil.

METHODS

Between 2015 and 2016, a cross-sectional study was conducted on 624 truck drivers who operate on the BR-050 highway in Brazil. Participants were interviewed about sociodemographic data, occupational characteristics, mental health, behavioral data, and tobacco use. Then, the Fagerstrom test for nicotine dependence (FTND) was used to verify nicotine dependence in smoking truck drivers. Logistic regression and linear regression were also used to verify factors associated with tobacco use in the previous 30 days and nicotine dependence scores, respectively.

RESULTS

The prevalence of tobacco use among truck drivers was 21.1% (n = 132;95%CI: 18.1-24.5). Of the total number of smokers who responded to the FTND (n = 118; 89.4%), most had high/very high nicotinic dependence (68.6%; 95%CI: 59.8-76.3). Tobacco use was associated with absence of religion (adjusted odds ratio [AOR]: 2.60; 95%CI: 1.35-5.01), employment relationship of the contract (AOR = 1.98; 95%CI: 1.26-3.13); > 12 hours daily working time (AOR = 1.80; 95%CI: 1.09-2.98) and alcohol use in the previous 30 days (AOR = 2.92; 95%CI: 1.86-4.57). Irregular physical activity was associated with higher scores of nicotine dependence (β = 1.87; 95%CI: 0.55-3.19).

CONCLUSION

The results showed a high prevalence of tobacco use and high/very high nicotine dependence among the truck drivers.

Effects of traditional Chinese exercises on mental health in individuals with drug rehabilitee: A systematic review and meta-analysis

Purpose

The intent of this systematic review and meta-analysis was to examine the effects of Traditional Chinese Exercise (TCE) on mental health and drug cravings in drug rehabilitees.

Methods

Six electronic databases (PubMed, Web of Science, MEDLINE, CINAHL, PsycArticles, and CNKI) were searched to identify the potential literature from inception to March 2022. The controlled studies with a pro-posttest design that investigated the effects of TCE on mental health (depression, anxiety, drug craving, and sleep quality) were included. The effect sizes were calculated using the random-effect models with a 95% confidence interval. The Physiotherapy Evidence Database (PEDro) scale was employed to evaluate study quality.

Results

A total of 10 studies (740 participants, mean age 35 years old) were included in this study. The pooled results showed that TCE produced significant improvements in depression (SMD = 0.65, 95% CI 0.29 to 1.02, p &lt; 0.01), anxiety (SMD = 0.98, 95% CI 0.44 to 1.53, p &lt; 0.01), and drug craving (SMD = 0.87, 95% CI 0.54 to 1.21, p &lt; 0.01) compared to the control group. The subgroup analysis results showed that TCE resulted in significant improvements in depression compared to active intervention (SMD = 0.33, 95% CI 0.07 to 0.60) or passive intervention (SMD = 1.07, 95% CI 0.40 to 1.74). A significant improvement in depression was observed in both male and female drug rehabilitee (p &lt; 0.05). Moreover, Tai Chi (SMD = 0.69, 95% CI 0.19 to 1.18) or Qigong (SMD = 0.49, 95% CI 0.24 to 0.74) exercise, 3–4 times per week (SMD = 1.06, 95% CI 0.39 to 1.74) or ≥5 times (SMD = 0.39, 95% CI 0.12 to 0.66), &gt;45 min (SMD = 0.62, 95% CI 0.09 to 1.15) or ≤ 45 min (SMD = 0.68, 95% CI 0.10 to 1.27), and for a duration of 12 weeks (SMD = 0.84, 95% CI 0.15 to 1.54) produced significant improvement in depression.

Conclusion

This current study suggests that TCE (Tai Chi, Qigong) may have benefits in alleviating depression, anxiety, and drug cravings in drug rehabilitees. Further studies are required to verify our results through the implementation of well-designed experimental protocols.

Effects of exercise training on depression and anxiety with changing neurotransmitters in methamphetamine long term abusers: A narrative review

Study aim: It is generally accepted that methamphetamine (MA) is a highly addictive psychostimulant which copies functions of certain neurotransmitters in the brain, and emits dopamine and serotonin in the brain. Frequent abuse of methamphetamine damages dopaminergic and serotonergic nerve endings at different sites of brain and also increases the anxiety and depression. Exercise seems to reverse physiological and neurological damages due to previous MA dependents and help to reduce anxiety and depression in this population. The aim is to determine the effect of exercise training on neurotransmitters and rate of depression and anxiety in chronic methamphetamine abusers based on a literature review.

Materials and methods: The present study investigated published articles in five computerized databases including Magiran, Google scholars, SID, PubMed and Scopus from 2011 until 2020. The searched keywords included sports, neurotransmitter, methamphetamine, depression, anxiety and treatment. The obtained results were described using texts, table and figure.

Results: According to the results, physical activity and exercise significantly increased blood serotonin and dopamine levels and significantly decreased the depression and anxiety.

Conclusion: Different evidences suggested that physical activity and exercise as positive responses and adaptations might influence on circulatory levels of two neurotransmitters (serotonin and dopamine) in methamphetamine addicts, decrease anxiety and depression, and improve preparation in previous MA dependents. In the rehabilitation period, the overall improvement in previous MA dependents might significantly increase. Exercise training can improve the physical and mental state of people addicted to methamphetamine as a non-drug therapy to promote health. However, more research is necessary to support this conclusion.

Effects of Acute Moderate- and High-Intensity Aerobic Exercise on Oxygenation in Prefrontal Cortex of Male Methamphetamine-Dependent Patients

The aim of this study was to explore the influence of different intensities of acute aerobic exercise on brain activation in male methamphetamine (MA)-dependent patients during exercise. Twenty MA-dependent patients were divided randomly into two groups participating in 35 min of either moderate- or high-intensity aerobic exercise. Functional near-infrared spectral imaging (fNIRS) was used to detect hemodynamic changes in prefrontal cortex during the main 25-min exercise stage. The results revealed that high-intensity acute aerobic exercise aroused more cerebral oxygenation changes in the prefrontal cortex and left dorsolateral prefrontal cortex during exercise as compared with moderate-intensity exercise. Furthermore, there was a stronger positive connection observed between orbital frontal cortex and left dorsolateral prefrontal cortex in the high-intensity group than in the moderate-intensity group. Together these results suggest that for submaximal exercise intensities, high-intensity exercise may bring more benefits to male MA-dependent patients than moderate-intensity.

Aerobic exercise as a promising nonpharmacological therapy for the treatment of substance use disorders

Despite the prevalence and public health impact of substance use disorders (SUDs), effective long-term treatments remain elusive. Aerobic exercise is a promising, nonpharmacological treatment currently under investigation as a strategy for preventing drug relapse. Aerobic exercise could be incorporated into the comprehensive treatment regimens for people with substance abuse disorders. Preclinical studies of SUD with animal models have shown that aerobic exercise diminishes drug-seeking behavior, which leads to relapse, in both male and female rats. Nevertheless, little is known regarding the effects of substance abuse-induced cellular and physiological adaptations believed to be responsible for drug-seeking behavior. Accordingly, the overall goal of this review is to provide a summary and an assessment of findings to date, highlighting evidence of the molecular and neurological effects of exercise on adaptations associated with SUD.

Voluntary exercise as a treatment for incubated and expanded drug craving leading to relapse to addiction: Animal models

Drug addiction is a chronic relapsing disorder, as more than 80% of former drug users relapse within a year after quit attempts have ended. This review examines incubated craving that develops over long periods of weeks to months after addictive drug use ends, when rats are given a small priming exposure to the formerly used drug, and a large amount of drug seeking occurs, reflecting large increases in craving over time. Expanded craving occurs when not only the recently-used drug, but other related or unrelated drugs of abuse elicit drug seeking that leads to relapse behavior, including common drugs like caffeine or nicotine, Thus, expanded craving is an increase in the conditions that elicit relapse, such as, a variety of drugs, and it persists weeks after drug use ends. Incubated and expanded craving occur with several drugs of abuse, and these forms of craving, can last for weeks to months and end in relapse. Voluntary physical exercise, blocked incubated cocaine craving, and expanded heroin craving elicited by multiple conditions was reduced in female and male rats. This review examines voluntary physical exercise as a long-term, self-initiated, and self-sustainable treatment that reduces long-term drug craving leading to relapse.

The Influence of Moderate Physical Activity on Brain Monoaminergic Responses to Binge-Patterned Alcohol Ingestion in Female Mice

Monoamine neurotransmitter activity in brain reward, limbic, and motor areas play key roles in the motivation to misuse alcohol and can become modified by exercise in a manner that may affect alcohol craving. This study investigated the influence of daily moderate physical activity on monoamine-related neurochemical concentrations across the mouse brain in response to high volume ethanol ingestion. Adult female C57BL/6J mice were housed with or without 2.5 h of daily access to running wheels for 30 days. On the last 5 days, mice participated in the voluntary binge-like ethanol drinking procedure, “Drinking in the dark” (DID). Mice were sampled immediately following the final episode of DID. Monoamine-related neurochemical concentrations were measured across brain regions comprising reward, limbic, and motor circuits using ultra High-Performance Liquid Chromatography (UHPLC). The results suggest that physical activity status did not influence ethanol ingestion during DID. Moreover, daily running wheel access only mildly influenced alcohol-related norepinephrine concentrations in the hypothalamus and prefrontal cortex, as well as serotonin turnover in the hippocampus. However, access to alcohol during DID eliminated wheel running-related decreases of norepinephrine, serotonin, and 5-HIAA content in the hypothalamus, but also to a lesser extent for norepinephrine in the hippocampus and caudal cortical areas. Finally, alcohol access increased serotonin and dopamine-related neurochemical turnover in the striatum and brainstem areas, regardless of physical activity status. Together, these data provide a relatively thorough assessment of monoamine-related neurochemical levels across the brain in response to voluntary binge-patterned ethanol drinking, but also adds to a growing body of research questioning the utility of moderate physical activity as an intervention to curb alcohol abuse.

Prescription Opioid Use and Laboratory Value Derangements: A Cross-Sectional Analysis of NHANES Data

BACKGROUND

The use of opioids for the treatment of pain is a risk versus benefit analysis and metabolic disease is an often overlooked variable in the equation and may lead to increased risk of comorbidities of cardiovascular and cerebrovascular disease and diabetes.

OBJECTIVES

Our objective was to identify and describe abnormalities among the comprehensive metabolic and lipid panels of individuals taking prescription opioids.

STUDY DESIGN

We performed a cross-sectional study of the laboratory values with 3 cycles (2011-2016) of the National Health and Nutrition Examination Survey (NHANES) in March 2020.

SETTING

NHANES sampling is conducted using a multistaged, stratified, cluster sampling technique to create a representative sample of the United States.

METHODS

We excluded patients with histories of cancer and under the age of 25 years. Our final sample size was 11,061 (n = 162,547,635), with 797 reportedly using a prescription opioid in the past 30 days-a weighted percent representing 22.95% of the US population. Our analyses identified mean differences in biomarkers between individuals taking prescription opioids and the US population.

RESULTS

Laboratory values from the comprehensive metabolic panel were all within reference ranges for both groups, with only bilirubin levels being statistically lower in the group currently taking prescription opioids. Values from the lipid panel of both the opioid using and comparison groups were above reference range for total cholesterol and fasting glucose. The opioid using group was also higher than the reference range for triglycerides (mean [M] = 165.4, standard deviation [SD] = 14.2) and insulin (M = 15.5, SD = 2.2), whereas the comparison group was not.  The oral glucose measure was within normal ranges for both groups; however, the opioid using group was 13.7 points higher than the comparison group (M = 122.3, SD = 1.8; M = 108.6, SD = 4.0; P < 0.01).

LIMITATIONS

While our study uses a large sample for a robust generalizable analysis it is a correlation study and a longitudinal cohort would provide better evidence linking potential disease states to prescription opioid use.

CONCLUSIONS

Although all Americans should be alarmed at the lipid levels reported in this study, specific combinations of heightened lipid laboratory values among prescription opioid users accelerate the trajectories toward comorbidities-heart disease, cerebrovascular disease, and diabetes-leading to diminished quality of life. Therefore pain management and comprehensive drug recovery programs should include nutritional counseling and physical activity as part of their overall treatment plan.

Investigating the Associations among Drug Dependents' Family Function and Exercise Attitudes: Marital Status Differences

This paper examines: (1) The demographic characteristics of different marital statuses of drug dependents; (2) differences in exercise attitudes and family function by marital status; and (3) if family function factors correlated with exercise attitudes and if exercise attitude factors correlated with family function. Multivariate analyses of variance (MANOVAs) revealed significant differences in drug dependents’ exercise attitudes between married and single groups (p < 0.05) and the married and “other” groups (p < 0.01). Furthermore, we observed significant differences in drug dependents’ family function between married and single groups (p < 0.01) and married and other groups (p < 0.05). Regression analyses indicated that communication [F_change(1,1791) = 137.819; p < 0.001] was a significant positive predictor for drug dependents’ exercise attitude, accounting for 7.1% of the observed variance. Moreover, 50% of the variance was explained by willingness [F_change(1,1791) = 850.49, p < 0.001] and control [F_change(1,1790) = 141.415, p < 0.001], which were two significant predictors of drug dependents’ family function. Findings of this study were: (1) Exercise attitude and family function of married drug dependents were better than single drug dependents and other marital status addicts; (2) communication was observed as a factor of family function that correlated with exercise attitude; and (3) willingness was related with family function.

Effects of exercise programs on neuroelectric dynamics in drug addiction

Exercise interventions have been considered to be an effective treatment for drug addiction. However, there is little dirct evidence that exercise affects brain activity in individuals afftected by drug addiction. Therefore, the aim of the present study was to investigate the effects of different exercise programs on detoxification. Cognitive recovery with 64-channel electroencephalography (EEG) recordings was obtained before and after three months of daily aerobic and anaerobic exercise. A total of 63 subjects with methamphetamine addiction were recruited and randomly divided into three groups for cognitive study in four behavioral states: an anaerobic resistance treatment group, an aerobic cycling treatment group and a control group. In addition, four behavioral states were examined: eyes-closed and eyes-open resting states, and exploratory behavior states following either drug- or neutral-cue exposure. Over a 12-week period,the alpha block ratio in the control group showed a slight decrease, while clear increases were observed in the resistance exercise and cycling treatment groups, particularly under the frontal and temporal regions in the eyes-open and drug-cue conditions. The major EEG activity frequency in the resistance treatment group during the drug-cue behavior task decreased compared with the frequencies of the cycling exercise and control groups. Meanwhile, the power of higher brain rhythms in the resistance treatment group was increased. Finally, the brain alpha wave left-lateralization index from EEG recording sites, F1-F2, in the resistance and cycling treatment groups under the eyes-closed condition positively decreased, while the control groups only showed slight decreases. Taken together, these results suggest that different types of exercise may induce distince and different positive therapeutic effects to facilitate detoxification.

Acute Aerobic Exercise Ameliorates Cravings and Inhibitory Control in Heroin Addicts: Evidence From Event-Related Potentials and Frequency Bands

Objective

Aerobic exercise is considered a potential adjunctive treatment for heroin addicts, but little is known about its mechanisms. Less severe cravings and greater inhibitory control have been associated with reduced substance use. The aim of the current study was to determine the effects, as measured by behavioral and neuroelectric measurements, of acute aerobic exercise on heroin cravings and inhibitory control induced by heroin-related conditions among heroin addicts.

Design

The present study used a randomized controlled design.

Methods

Sixty male heroin addicts who met the DSM-V criteria were recruited from the Isolated Detoxification Center in China and randomly assigned to one of two groups; one group completed a 20-min bout of acute stationary cycle exercise with vigorous intensity (70-80% of maximum heart rate, exercise group), and the other group rested (control group). The self-reported heroin craving levels and inhibitory control outcomes (measured by a heroin-related Go/No-Go task) were assessed pre- and post-exercise.

Results

The heroin craving levels in the exercise group were significantly attenuated during, immediately following, and 40 min after vigorous exercise compared with before exercise; moreover, during exercise, a smaller craving was observed in the exercise group than in the control group. Acute exercise also facilitated inhibition performance in the No-Go task. After exercise, the participants' accuracy, the N2d amplitudes, and the theta two band spectral power during the No-Go conditions were higher in the exercise group than in the control group. Interestingly, significant correlations between the changes in these sensitive measurements and the changes in cravings were observed.

Conclusions

This is the first empirical study to demonstrate that aerobic exercise may be efficacious for reducing heroin cravings and promoting inhibitory control among heroin addicts.

Effects of circuit-type resistance training on industrial opiate induced neurotransmitter disruption and performance changes of previously addicted men

Study aim: The aim of this study was to examine the effects of an 8-week circuit-type resistance training program on performance changes and neurotransmitter disruptions induced by industrial opiate in previously addicted men.

Materials and methods: Thirty industrial opiate addicted men volunteered to participate in this study and were randomly assigned to experimental (n = 15) and control groups (n = 15). The subjects in the experimental group performed circuit-type resistance training for 8 weeks, 3 days a week, with 40–75% of one-repetition maximum (1RM), while the control group did not perform any training. Before and after the training period muscular strength (1RM of bench press) and muscle endurance (sit-ups), flexibility (sit-and-reach), body fat percentage, waist-to-hip ratio (WHR) and cardio-respiratory endurance were measured. In addition, blood samples were drawn 24 h before and after 8 weeks of training to analyze serum levels of serotonin, dopamine, and endorphins.

Results: In this study, 8 weeks of circuit-type resistance training led to significantly higher serum levels of serotonin, dopamine, and endorphins, cardio-respiratory endurance, muscular strength and endurance in the experimental group compared to controls (P < 0.05), while flexibility, body fat percentage and WHR did not differ significantly (P > 0.05).

Conclusions: In conclusion, circuit resistance training can improve the serum levels of serotonin, dopamine, and endorphins, as well as indicators of health-related performance previously industrial opiate addicted men.

Managing Substance Use Disorder through a Walking/Running Training Program

While emerging studies have demonstrated the benefit of exercise in Substance Use Disorder (SUD) recovery outcomes, lack of motivation to engage in exercise has been indicated as one of many perceived barriers that contribute to low recruitment and adherence rates in SUD treatment. The current study aimed to explore participants' perceptions of attending a supervised exercise program (boot camp workouts, walking/running practice, and a race event) while in treatment for SUD. A total of 109 participants were recruited to a 14-week exercise training program and 61 chose to participate in, and completed, a race at the close of the program. Interviews were conducted during weeks 6 through 14 and data were examined using Thematic Analysis. Three main themes were identified: (1) pushing forward recovery through running, (2) gaining a sense of achievement by crossing the finish line, and (3) building a sense of belonging in the program. Implications for SUD recovery programs are discussed.

Effects of voluntary exercise and sex on multiply-triggered heroin reinstatement in male and female rats

BACKGROUND

The rise in heroin addiction has heightened the need for novel and effective treatments. Physical exercise has been shown as an effective treatment for stimulant abuse in clinical and pre-clinical research. However, this treatment has not yet been tested on opioid addiction. This study examined the effects of physical activity (wheel running) on heroin-seeking in rats within a reinstatement paradigm (i.e., heroin relapse model).

METHODS

Female and male rats were trained to self-administer intravenous heroin (0.015 mg/kg). Once trained, rats were placed into extinction (i.e., heroin abstinence) for 21 days with continuous access to a locked or unlocked running wheel. After extinction, rats were tested for drug- (heroin, caffeine, and yohimbine) and cue-primed reinstatement of heroin-seeking.

RESULTS

Females completed more wheel revolutions than males across all study phases. Access to an unlocked running wheel reduced extinction and reinstatement of heroin-seeking, with greater reductions in females than males across several reinstatement conditions. In the locked wheel group, female rats showed greater reinstatement of heroin-seeking than males across several priming conditions.

CONCLUSIONS

Wheel running reduced heroin-seeking in male and female rats, with females showing a more robust effect during reinstatement. The locked wheel group allowed an examination of sex differences in heroin reinstatement, which revealed that females showed greater vulnerability to heroin reinstatement than males, but with no other sex differences observed in maintenance or extinction. Overall, the results indicate that voluntary physical exercise may be an effective treatment for heroin dependence in humans.

Nonhuman animal models of substance use disorders: Translational value and utility to basic science

BACKGROUND

The National Institute on Drug Abuse (NIDA) recently released a Request for Information (RFI) soliciting comments on nonhuman animal models of substance use disorders (SUD).

METHODS

A literature review was performed to address the four topics outlined in the RFI and one topic inspired by the RFI: (1) animal models that best recapitulate SUD, (2) animal models that best balance the trade-offs between resources and ecological validity, (3) animal models whose translational value are frequently misrepresented or overrepresented by the scientific community, (4) aspects of SUD that are not currently being modeled in animals, and (5) animal models that are optimal for examining the basic mechanisms by which drugs produce their abuse-related effects.

RESULTS

Models that employ response-contingent drug administration, use complex schedules of reinforcement, measure behaviors that mimic the distinguishing features of SUD, and use animals that are phylogenetically similar to humans have the greatest translational value. Models that produce stable and reproducible baselines of behavior, lessen the number of uncontrolled variables, and minimize the influence of extraneous factors are best at examining basic mechanisms contributing to drug reward and reinforcement.

CONCLUSIONS

Nonhuman animal models of SUD have undergone significant refinements to increase their utility for basic science and translational value for SUD. The existing literature describes numerous examples of how these models may best be utilized to answer mechanistic questions of drug reward and identify potential therapeutic interventions for SUD. Progress in the field could be accelerated by further collaborations between researchers using animals versus humans.

Aerobic Exercise Interventions for Patients in Opioid Maintenance Treatment: A Systematic Review

Background:

Opioid maintenance treatment (OMT) is the standard for treatment of opioid use disorder, but some individuals on OMT experience disrupted sleep, heightened sensitivity to pain, and continued relapse to non-medical opioid use. An adjunctive treatment that has potential to address these shortcomings of OMT is aerobic exercise.

Objective:

The aim of the present review was to identify and evaluate components of aerobic exercise interventions targeting OMT patients.

Methods:

For this PROSPERO-registered review (ID CRD42020139626), studies were identified via electronic bibliographic databases, funded research (NIH RePORTER) and clinical trials databases (ClinicalTrials.gov), and reference sections of relevant manuscripts. Studies that evaluated the effects of an aerobic exercise intervention using a comparison condition or pretest-posttest design in adult OMT patients were included.

Results:

Of 2971 unique records, three primary studies and one supplemental manuscript comprised the final sample. All studies were randomized trials involving supervised exercise interventions enrolling small samples of middle-aged OMT patients. Exercise interventions included a variety of aerobic and non-aerobic activities (e.g. flexibility exercises), and none controlled the dose of aerobic exercise. Few studies used objective measures of physical activity or cardiorespiratory fitness and there were no significant effects of adjunctive exercise on substance use outcomes, but tests of the latter were likely underpowered.

Conclusions:

Though early in the accumulation of evidence, interventions targeting aerobic exercise for OMT patients appear feasible, acceptable to patients, and beneficial. Longer-term studies that employ larger samples, include assessments of behavioral and biological mechanisms of change, more rigorous measurement of physical activity, and controlled doses of aerobic activity are warranted.

Concurrent Effects of Exercise and Curcumin on Spatial Learning and Memory in Sensitized Male Mice Following Morphine Administration

Background:

Exercise and Curcumin have positive effects on spatial memory and cognition independently. The present study aims to investigate whether the combination of ineffectual dosage of these factors can affect cognition and as a solvent if DMSO is involved in Curcumin effects.

Materials and Methods:

Male NMRI mice (1-month-old) swam (1 week) for 60 minutes (5days/week) and injected with morphine (2.5 mg/ml/kg, intraperitoneal) for five days. Spatial learning and memory were assessed by Moris Water Maze test on the 10th day after stopping morphine injection.

Results:

The findings revealed that exercise, dimethyl sulfoxide (DMSO), and Curcumin increased memory formation induced by 2.5 mg/ml/kg morphine. DMSO+exercise decreased memory formation induced by morphine, but curcumin +exercise could return the effect of DMSO on the cognition.

Conclusion:

As a solvent, DMSO had independent effects on memory, which lead to memory impairment in combination with exercise. Therefore, considering its unpredictable effects on cognitive performance, it should be replaced with another solvent or might be used carefully in behavioral experiments.

The Effect of High-Intensity Interval/Circuit Training on Cognitive Functioning and Quality of Life During Recovery From Substance Abuse Disorder. A Study Protocol

This proposed study will examine whether structured physical activity reduces the recovery time of cognitive functioning during the early phase of substance use disorder treatment. Addiction or substance dependence is associated with neurobiological changes and cognitive impairment that can affect quality of life and the efficacy of therapy for up to a year after clinical detoxification. The biological, psychological, and social effects of physical exercise have the potential to be a therapeutic approach to increase quality of life and relieve symptoms associated with substance abuse, such as psychosis, depression, and anxiety. There is a dearth of research on physical activity and exercise in clinical substance use disorder patients. This protocol describes a clinical study that will examine cognitive recovery after substance abuse using physical exercise as a treatment intervention. We will use a quasi-experimental longitudinal clinical trial, with a pretest and multiple posttests, on naturally randomized sequential groups. Patients will be consecutively be recruited into the study groups, with a control group that is completed, before its followed by an intervention group, each with 30 patients. Patients will be enrolled 2 weeks after the start of detoxification, at which time all subjects will be inpatients at the Stavanger Salvation Army Treatment Center in the Norwegian specialized healthcare system. Cognition will be evaluated with a comprehensive battery of cognitive tests, including several tests of executive function. Physical fitness will be tested with the Rockport 1-Mile Walk Test, the 30-S Chair Stand Test, the 1-Min Burpee Test at baseline (within the first 2 weeks of admittance) and after 4 weeks. The intervention will be a 30-min workout at 70–90% of maximum heart rate (134–170 bpm), recorded and calculated by a Polar heart rate monitor. The intervention treatment will be administered four times a week for 4 weeks and will consist of high-intensity circuit training, high-intensity interval training, functional movement, and primitive reflex training. We anticipate improvement in both the control and intervention groups, with the exercise intervention group having the greatest increase in recovery of cognitive function because of the combination of functional full body movements and primitive movement training in an intense interval training program.

Clinical Trial Registration ID: ISRCTN74750479, Retrospectively Registered.

The Go-VAR (Veterans Active Recovery): An Adjunctive, Exercise-Based Intervention for Veterans Recovering from Substance Use Disorders

Substance use disorders (SUD) are prevalent among veterans, and the relapse rate is estimated at ≥60% within one year of treatment. Exercise's broad health benefits make it an appealing adjunctive component to interventions preventing relapse among individuals with SUDs. After conducting formative research, we designed and conducted the Go-VAR! (Veterans Active Recovery) pilot study to examine the feasibility and acceptability of a multi-component exercise-based intervention for veterans seeking SUD treatment through the outpatient Alcohol & Drug Treatment Program (ADTP) at the VA San Diego Healthcare System (VASDHS). Participants (N = 15; mean age = 45 [SD = 9.7]; 13% Hispanic, 60% White) from the La Jolla VASDHS outpatient ADTP were enrolled in this 12-week one-arm pilot study. Feasibility and acceptability were established: 70% of participants attended weekly psychoeducation groups, wore their Fitbit Charge HR, increased their weekly physical activity, and used their study-provided YMCA memberships, group exercise training sessions, and Fit4Me personal training program. Lower use of both alcohol and drugs were reported at the end of the study (p < .0001). Significant increases in daily steps as measured by the Fitbit HR and improvements in measures of physical fitness were also achieved (p < .05). Future work should focus on potential integration within the VA system.

Rewiring the Addicted Brain Through a Psychobiological Model of Physical Exercise

Drug addiction is a worldwide public health problem, resulting from multiple phenomena, including those both social and biological. Chronic use of psychoactive substances has been shown to induce structural and functional changes in the brain that impair cognitive control and favor compulsive seeking behavior. Physical exercise has been proven to improve brain function and cognition in both healthy and clinical populations. While some studies have demonstrated the potential benefits of physical exercise in treating and preventing addictive behaviors, few studies have investigated its cognitive and neurobiological contributions to drug-addicted brains. Here, we review studies in humans using cognitive behavioral responses and neuroimaging techniques, which reveal that exercise can be an effective auxiliary treatment for drug addictive disorders. Moreover, we describe the neurobiological mechanisms by which exercise-induced neuroplasticity in the prefrontal cortex improves executive functions and may decrease compulsive behaviors in individuals prone to substance use disorders. Finally, we propose an integrative cognitive-psychobiological model of exercise for use in future research in drug addiction and practical guidance in clinical settings.

Gender-specific HIV and substance abuse prevention strategies for South African men: study protocol for a randomized controlled trial

BACKGROUND

Young men in South Africa face concurrent epidemics of HIV, drug and alcohol abuse, and unemployment. Standard HIV prevention programs, located in healthcare settings and/or using counseling models, fail to engage men. Soccer and vocational training are examined as contexts to deliver male-specific, HIV prevention programs.

METHODS

Young men (n = 1200) are randomly assigned by neighborhood to one of three conditions: 1) soccer league (n = 400; eight neighborhoods); 2) soccer league plus vocational training (n = 400; eight neighborhoods); or 3) a control condition (n = 400; eight neighborhoods). Soccer practices and games occur three times per week and vocational training is delivered by Silulo Ulutho Technologies and Zenzele Training and Development. At baseline, 6 months, 12 months, and 24 months, the relative efficacy of these strategies to increase the number of significant outcomes (NSO) among 15 outcomes which occur (1) or not (0) are summed and compared using binomial logistic regressions. The summary primary outcome reflects recent HIV testing, substance abuse, employment, sexual risk, violence, arrests, and mental health status.

DISCUSSION

The failure of men to utilize HIV prevention programs highlights the need for gender-specific intervention strategies. However, men in groups can provoke and encourage greater risk-taking among themselves. The current protocol evaluates a male-specific strategy to influence men's risk for HIV, as well as to improve their ability to contribute to family income and daily routines. Both interventions are expected to significantly benefit men compared with the control condition.

TRIAL REGISTRATION

ClinicalTrials.gov registration, NCT02358226 . Registered 24 November 2014.

Virtual Reality Cue Refusal Video Game for Alcohol and Cigarette Recovery Support: Summative Study

BACKGROUND

New technologies such as virtual reality, augmented reality, and video games hold promise to support and enhance individuals in addiction treatment and recovery. Quitting or decreasing cigarette or alcohol use can lead to significant health improvements for individuals, decreasing heart disease risk and cancer risks (for both nicotine and alcohol use), among others. However, remaining in recovery from use is a significant challenge for most individuals.

OBJECTIVE

We developed and assessed the Take Control game, a partially immersive Kinect for Windows platform game that allows users to counter substance cues through active movements (hitting, kicking, etc).

METHODS

Formative analysis during phase I and phase II guided development. We conducted a small wait-list control trial using a quasi-random sampling technique (systematic) with 61 participants in recovery from addiction to alcohol or tobacco. Participants used the game 3 times and reported on substance use, cravings, satisfaction with the game experience, self-efficacy related to recovery, and side effects from exposure to a virtual reality intervention and substance cues.

RESULTS

Participants found the game engaging and fun and felt playing the game would support recovery efforts. On average, reported substance use decreased for participants during the intervention period. Participants in recovery for alcohol use saw more benefit than those in recovery for tobacco use, with a statistically significant increase in self-efficacy, attitude, and behavior during the intervention. Side effects from the use of a virtual reality intervention were minor and decreased over time; cravings and side effects also decreased during the study.

CONCLUSIONS

The preliminary results suggest the intervention holds promise as an adjunct to standard treatment for those in recovery, particularly from alcohol use.

Resistance exercise decreases heroin self-administration and alters gene expression in the nucleus accumbens of heroin-exposed rats

RATIONALE

Preclinical studies consistently report that aerobic exercise decreases drug self-administration and other forms of drug-seeking behavior; however, relatively few studies have examined other types of physical activity.

OBJECTIVES

The purpose of the present study was to examine the effects of resistance exercise (i.e., strength training) on heroin self-administration and mRNA expression of genes known to mediate opioid reinforcement and addictive behavior in the nucleus accumbens (NAc) of heroin-exposed rats.

METHODS

Female rats were obtained during late adolescence and divided into two groups. Resistance exercise rats were trained to climb a vertical ladder wearing a weighted vest; sedentary control rats were placed repeatedly on the ladder oriented horizontally on its side. All rats were implanted with intravenous catheters and trained to self-administer heroin on a fixed ratio (FR1) schedule of reinforcement. mRNA expression in the NAc core and shell was examined following behavioral testing.

RESULTS

Resistance exercise significantly decreased heroin self-administration, resulting in a downward shift in the dose-effect curve. Resistance exercise also reduced mRNA expression for mu opioid receptors and dopamine D1, D2, and D3 receptors in the NAc core. Resistance exercise increased mRNA expression of dopamine D5 receptors in the NAc shell and increased mRNA expression of brain-derived neurotrophic factor (exons I, IIB, IIC, IV, VI, IX) in the NAc core.

CONCLUSIONS

These data indicate that resistance exercise decreases the positive reinforcing effects of heroin and produces changes in opioid and dopamine systems in the NAc of heroin-exposed rats.

A Behavioral Economic Analysis of Marijuana and Other Drug Use Among Heavy Drinking Young Adults

Objective

Behavioral economic models predict that deficits in substance-free reward and future time orientation are associated with greater drug involvement, but this hypothesis has not been systematically investigated among young adult heavy drinkers. This study evaluated the association between drug use levels (heavy drinking (HD) only, HD + marijuana use, and HD + polysubstance use) and substance-free activity engagement, future orientation, and reward deprivation (comprised of reward experience and environmental suppressors of reward) among heavy drinkers.

Method

Participants were 358 college students who reported two or more past-month heavy drinking episodes (5/4 or more drinks in one occasion for a man/woman). The sample was 60% women, 79% Caucasian, and the average age was 18.76 (SD = 1.07) years. Participants completed measures of alcohol and drug use, weekly time allocation to various activities, future time orientation, and reward deprivation.

Results

Overall, any drug use was associated with less time spent engaged in academics and exercise, and lower future time orientation compared to HD only. Any drug use was associated with reward deprivation and HD + polysubstance use was associated with lower reward experience and environmental suppressors.

Conclusion

Drug use among heavy drinkers is associated with lower academic engagement and exercise, future orientation, and reward deprivation. These results provide support for behavioral economic models of drug abuse and suggest that prevention approaches should attempt to increase future orientation and availability of drug-free reward.

Leisure-time physical activity and prevalence of non-communicable pathologies and prescription medication in Spain

Our aims were to describe physical activity (PA) behaviour in Spain and to examine its association with the prevalence of some of the major non-communicable diseases and with the use of prescription medication. Individualized secondary data retrieved from the 2014 European Health Interview Survey (EHIS) for Spain were used to conduct a cross-sectional epidemiological study (n = 18926). PA was assessed by two different measures: a specific designed variable for EHIS and a leisure time PA frequency-based query of the national survey. Diseases analyzed were hypertension, diabetes, hypercholesterolemia, depression and anxiety. The use of prescription medication was also included in the study. Weighted percentages were computed and contingency tables were calculated to describe PA by levels of the traits and sociodemographic characteristics. Chi-square test was used to compare percentages between groups and weighted logistic regression models were used to assess the relationship between PA and the prevalence of the disease. About 73% of the Spanish population performs no PA at all or only occasionally during their leisure time, and only one third meets minimum PA international guidelines (≥ 150min/week). Men are considerably more active than women and less PA is observed as the education level decreases and as age increases. The risk of the diseases evaluated was up to three times higher among inactive individuals. This study provides national population-based estimations highlighting the impact of PA in Spain, not only in the prevalence of some of the major non-communicable diseases but also in reducing prescription medication, and the potential sex and socioeconomic influence.

Social Status in Monkeys: Effects of Social Confrontation on Brain Function and Cocaine Self-Administration

Individual differences in response to social stress and environmental enrichment may contribute to variability in response to behavioral and pharmacological treatments for drug addiction. In monkeys, social status influences the reinforcing effects of cocaine and the effects of some drugs on cocaine self-administration. In this study, we used male cynomolgus macaques (n=15) living in established social groups to examine the effects of social confrontation on the reinforcing effects of cocaine using a food-drug choice procedure. On the test day, a dominant or subordinate monkey was removed from his homecage and placed into another social pen; 30 min later he was studied in a cocaine-food choice paradigm. For the group, following social confrontation, sensitivity to cocaine reinforcement was significantly greater in subordinate monkeys compared with dominant animals. Examining individual-subject data revealed that for the majority of monkeys (9/15), serving as an intruder in another social group affected cocaine self-administration and these effects were dependent on the social rank of the monkey. For subordinate monkeys, sensitivity to the reinforcing effects of cocaine increased while sensitivity decreased in dominant monkeys. To investigate potential mechanisms mediating these effects, brain glucose metabolism was studied in a subset of monkeys (n=8) using [18F]fluorodeoxyglucose ([18F]FDG) with positron emission tomography. Dominant and subordinate monkeys displayed distinctly different patterns of brain glucose metabolism in their homecage, including areas associated with vigilance and stress/anxiety, respectively, and during social confrontation. These data demonstrate that, depending on an individual's social status, the same social experience can have divergent effects on brain function and cocaine self-administration. These phenotypic differences in response to social conditions support a personalized treatment approach to cocaine addiction.

The Obesity-Impulsivity Axis: Potential Metabolic Interventions in Chronic Psychiatric Patients

Pathological impulsivity is encountered in a broad range of psychiatric conditions and is thought to be a risk factor for aggression directed against oneself or others. Recently, a strong association was found between impulsivity and obesity which may explain the high prevalence of metabolic disorders in individuals with mental illness even in the absence of exposure to psychotropic drugs. As the overlapping neurobiology of impulsivity and obesity is being unraveled, the question asked louder and louder is whether they should be treated concomitantly. The treatment of obesity and metabolic dysregulations in chronic psychiatric patients is currently underutilized and often initiated late, making correction more difficult to achieve. Addressing obesity and metabolic dysfunction in a preventive manner may not only lower morbidity and mortality but also the excessive impulsivity, decreasing the risk for aggression. In this review, we take a look beyond psychopharmacological interventions and discuss dietary and physical therapy approaches.

Animal models of resistance exercise and their application to neuroscience research

BACKGROUND

Numerous studies have demonstrated that participation in regular resistance exercise (e.g., strength training) is associated with improvements in mental health, memory, and cognition. However, less is known about the neurobiological mechanisms mediating these effects. The goal of this mini-review is to describe and evaluate the available animal models of resistance exercise that may prove useful for examining CNS activity.

NEW METHOD

Various models have been developed to examine resistance exercise in laboratory animals.

COMPARISON WITH EXISTING METHODS

Resistance exercise models vary in how the resistance manipulation is applied, either through direct stimulation of the muscle (e.g., in situ models) or through behavior maintained by operant contingencies (e.g., whole organism models). Each model presents distinct advantages and disadvantages for examining central nervous system (CNS) activity, and consideration of these attributes is essential for the future investigation of underlying neurobiological substrates.

RESULTS

Potential neurobiological mechanisms mediating the effects of resistance exercise on pain, anxiety, memory, and drug use have been efficiently and effectively investigated using resistance exercise models that minimize stress and maximize the relative contribution of resistance over aerobic factors.

CONCLUSIONS

Whole organism resistance exercise models that (1) limit the use of potentially stressful stimuli and (2) minimize the contribution of aerobic factors will be critical for examining resistance exercise and CNS function.

How to study sex differences in addiction using animal models

The importance of studying sex as a biological variable in biomedical research is becoming increasingly apparent. There is a particular need in preclinical studies of addiction to include both sexes, as female animals are often excluded from studies, leaving large gaps in our knowledge of not only sex differences and potential prevention and treatment strategies but also with regard to the basic neurobiology of addiction. This review focuses on methodology that has been developed in preclinical studies to examine sex differences in the behavioral aspects and neurobiological mechanisms related to addiction across the full range of the addiction process, including initiation (acquisition), maintenance, escalation, withdrawal, relapse to drug seeking and treatment. This review also discusses strategic and technical issues that need to be considered when comparing females and males, including the role of ovarian hormones and how sex differences interact with other major vulnerability factors in addiction, such as impulsivity, compulsivity and age (adolescent versus adult). Novel treatments for addiction are also discussed, such as competing non-drug rewards, repurposed medications such as progesterone and treatment combinations. Practical aspects of conducting research comparing female and male animals are also considered. Making sex differences a point of examination requires additional effort and consideration; however, such studies are necessary given mounting evidence demonstrating that the addiction process occurs differently in males and females. These studies should lead to a better understanding of individual differences in the development of addiction and effective treatments for males and females.

The effects of resistance exercise on cocaine self-administration, muscle hypertrophy, and BDNF expression in the nucleus accumbens

BACKGROUND

Exercise is associated with positive outcomes in drug abusing populations and reduces drug self-administration in laboratory animals. To date, most research has focused on aerobic exercise, and other types of exercise have not been examined. This study examined the effects of resistance exercise (strength training) on cocaine self-administration and BDNF expression, a marker of neuronal activation regulated by aerobic exercise.

METHODS

Female rats were assigned to either exercising or sedentary conditions. Exercising rats climbed a ladder wearing a weighted vest and trained six days/week. Training consisted of a three-set "pyramid" in which the number of repetitions and resistance varied across three sets: eight climbs carrying 70% body weight (BW), six climbs carrying 85% BW, and four climbs carrying 100% BW. Rats were implanted with intravenous catheters and cocaine self-administration was examined. Behavioral economic measures of demand intensity and demand elasticity were derived from the behavioral data. BDNF mRNA expression was measured via qRT-PCR in the nucleus accumbens following behavioral testing.

RESULTS

Exercising rats self-administered significantly less cocaine than sedentary rats. A behavioral economic analysis revealed that exercise increased demand elasticity for cocaine, reducing consumption at higher unit prices. Exercising rats had lower BDNF expression in the nucleus accumbens core than sedentary rats.

CONCLUSIONS

These data indicate that resistance exercise decreases cocaine self-administration and reduces BDNF expression in the nucleus accumbens after a history of cocaine exposure. Collectively, these findings suggest that strength training reduces the positive reinforcing effects of cocaine and may decrease cocaine use in human populations.

Voluntary wheel running reduces voluntary consumption of ethanol in mice: identification of candidate genes through striatal gene expression profiling

Hedonic substitution, where wheel running reduces voluntary ethanol consumption, has been observed in prior studies. Here, we replicate and expand on previous work showing that mice decrease voluntary ethanol consumption and preference when given access to a running wheel. While earlier work has been limited mainly to behavioral studies, here we assess the underlying molecular mechanisms that may account for this interaction. From four groups of female C57BL/6J mice (control, access to two-bottle choice ethanol, access to a running wheel, and access to both two-bottle choice ethanol and a running wheel), mRNA-sequencing of the striatum identified differential gene expression. Many genes in ethanol preference quantitative trait loci were differentially expressed due to running. Furthermore, we conducted Weighted Gene Co-expression Network Analysis and identified gene networks corresponding to each effect behavioral group. Candidate genes for mediating the behavioral interaction between ethanol consumption and wheel running include multiple potassium channel genes, Oprm1, Prkcg, Stxbp1, Crhr1, Gabra3, Slc6a13, Stx1b, Pomc, Rassf5 and Camta2. After observing an overlap of many genes and functional groups previously identified in studies of initial sensitivity to ethanol, we hypothesized that wheel running may induce a change in sensitivity, thereby affecting ethanol consumption. A behavioral study examining Loss of Righting Reflex to ethanol following exercise trended toward supporting this hypothesis. These data provide a rich resource for future studies that may better characterize the observed transcriptional changes in gene networks in response to ethanol consumption and wheel running.

The effects of physical activity on impulsive choice: Influence of sensitivity to reinforcement amount and delay

Impulsive choice is a diagnostic feature and/or complicating factor for several psychological disorders and may be examined in the laboratory using delay-discounting procedures. Recent investigators have proposed using quantitative measures of analysis to examine the behavioral processes contributing to impulsive choice. The purpose of this study was to examine the effects of physical activity (i.e., wheel running) on impulsive choice in a single-response, discrete-trial procedure using two quantitative methods of analysis. To this end, rats were assigned to physical activity or sedentary groups and trained to respond in a delay-discounting procedure. In this procedure, one lever always produced one food pellet immediately, whereas a second lever produced three food pellets after a 0, 10, 20, 40, or 80-s delay. Estimates of sensitivity to reinforcement amount and sensitivity to reinforcement delay were determined using (1) a simple linear analysis and (2) an analysis of logarithmically transformed response ratios. Both analyses revealed that physical activity decreased sensitivity to reinforcement amount and sensitivity to reinforcement delay. These findings indicate that (1) physical activity has significant but functionally opposing effects on the behavioral processes that contribute to impulsive choice and (2) both quantitative methods of analysis are appropriate for use in single-response, discrete-trial procedures.

Many correlates of poor quality of life among substance users entering treatment are not addiction-specific

Background

Quality of life (QoL) is an important measure and outcome within chronic disease management and treatment, including substance use disorders (SUD). The aim of this paper was to investigate correlates of poorer QoL of individuals entering SUD treatment in Norway, in order to identify subgroups that may most benefit from different interventions.

Methods

Twenty-one treatment facilities invited all incoming patients to participate. Five hundred forty-nine patients who enrolled between December 2012 and April 2015 are analyzed. QoL, substance use, mental and physical comorbidities, and exercise behaviors were measured. Multinomial regression analysis was used to determine variables significantly associated with poorer QoL.

Results

The majority of both genders (75 %) reported “poor” or “very poor” QoL at intake. Depression showed a strong association with poor QoL (relative risk ratio [RRR] 3.3, 95 % confidence interval [CI] 1.0–10.3) and very poor QoL (RRR 3.8, 1.2–11.8) among women. Physical inactivity among men was associated with very poor QoL (RRR 2.0, 1.1–3.7), as was reporting eating most meals alone (RRR 2.6, 1.4–4.8). Evaluating one’s weight as too low was also associated with poor QoL (RRR 2.0, 1.0-3.9) and very poor QoL (RRR 2.0, 1.1–3.7) among men. Consuming methadone/buprenorphine was a protective factor for men reporting poor QoL (RRR 0.5, 0.3–0.9) and very poor QoL (RRR 0.4, 0.2–0.9), as well as for women reporting very poor QoL (RRR 0.2, 0.0–0.6).

Conclusions

Factors associated with poorer QoL among other healthy and clinical populations, such as impaired social and physical well-being and psychological distress, were also seen associated in this sample. Treatment should be targeted towards patients with these particular vulnerabilities in addition to focusing on substance-related factors, and interventions proven to improve the QoL of other populations with these vulnerabilities should be explored in a SUD context.

Sex differences in drug addiction and response to exercise intervention: From human to animal studies

Accumulated research supports the idea that exercise could be an option of potential prevention and treatment for drug addiction. During the past few years, there has been increased interest in investigating of sex differences in exercise and drug addiction. This demonstrates that sex-specific exercise intervention strategies may be important for preventing and treating drug addiction in men and women. However, little is known about how and why sex differences are found when doing exercise-induced interventions for drug addiction. In this review, we included both animal and human that pulled subjects from a varied age demographic, as well as neurobiological mechanisms that may highlight the sex-related differences in these potential to assess the impact of sex-specific roles in drug addiction and exercise therapies.