Nutritional assessment of drug addicts

The role of morphine- and fentanyl-induced impairment of intestinal epithelial antibacterial activity in dysbiosis and its impact on the microbiota-gut-brain axis

Recent evidence suggests that chronic exposure to opioid analgesics such as morphine disrupts the intestinal epithelial layer and causes intestinal dysbiosis. Depleting gut bacteria can preclude the development of tolerance to opioid-induced antinociception, suggesting an important role of the gut-brain axis in mediating opioid effects. The mechanism underlying opioid-induced dysbiosis, however, remains unclear. Host-produced antimicrobial peptides (AMPs) are critical for the integrity of the intestinal epithelial barrier as they prevent the pathogenesis of the enteric microbiota. Here, we report that chronic morphine or fentanyl exposure reduces the antimicrobial activity in the ileum, resulting in changes in the composition of bacteria. Fecal samples from morphine-treated mice had increased levels of Akkermansia muciniphila with a shift in the abundance ratio of Firmicutes and Bacteroidetes. Fecal microbial transplant (FMT) from morphine-naïve mice or oral supplementation with butyrate restored (a) the antimicrobial activity, (b) the expression of the antimicrobial peptide, Reg3γ, (c) prevented the increase in intestinal permeability and (d) prevented the development of antinociceptive tolerance in morphine-dependent mice. Improved epithelial barrier function with FMT or butyrate prevented the enrichment of the mucin-degrading A. muciniphila in morphine-dependent mice. These data implicate impairment of the antimicrobial activity of the intestinal epithelium as a mechanism by which opioids disrupt the microbiota-gut-brain axis.

Diet quality, nutritional status and taste recognition are impaired in men with substance use disorder

This study aimed to (1) evaluate the nutritional status, prevalence of malnutrition and dietary habits in individuals using substances and (2) examine the possible effects of substance use on the perception of five basic tastes. Ninety male individuals with substance use disorder (SUD) (heroin = 78, cocaine = 12) and 32 non-users participated in the study conducted at Manisa Alcohol and Substance Addiction Treatment Center (AMATEM), Turkey. To determine the quality of the diet, the mean nutrient adequacy ratio (MAR) was calculated based on 24-h recall food consumption records of the individuals. Subjective Global Assessment (SGA) was employed to determine nutritional status, and anthropometric measurements were also taken from the individuals. The taste detection and recognition thresholds were determined with solutions with different concentrations for bitter, sour, sweet, umami and salty tastes and scored, with higher scores indicating lower thresholds. Mild-moderate malnutrition was determined in 50% of the individuals with SUD based on SGA. The body mass index (BMI) of individuals with SUD was found to be 21.2 ± 1.88 kg/m2 , and 24.1 ± 1.64 kg/m2 for non-users (p < 0.001). Diet quality, evaluated by MAR, was lower in individuals with SUD (54.7 ± 18.9%) than in non-users (93.5 ± 9.0%) (p < 0.001). The taste detection and taste recognition thresholds of individuals with SUD were impaired, and the threshold scores for sour, salty, sweet and umami taste recognition were significantly lower compared with non-users, with the lowest substance user threshold scores observed for the sweet recognition threshold. Standardised nutritional and behavioural interventions designed by dietitians should be provided for drug users in treatment centres and integrated with medical treatment practices.

The Role of Morphine-Induced Impairment of Intestinal Epithelial Antibacterial Activity in Dysbiosis and its Impact on the Microbiota-Gut-Brain Axis.. [PMID: 37503065 PMCID: PMC10371156 DOI: 10.21203/rs.3.rs-3084467/v2]

Recent evidence suggests that chronic exposure to opioid analgesics such as morphine disrupt the intestinal epithelial layer and cause intestinal dysbiosis. Inhibiting opioid-induced dysbiosis can preclude the development of tolerance to opioid-induced antinociception, suggesting an important role of the gut-brain axis in mediating opioid effects. However, the mechanism underlying opioid-induced dysbiosis remains unclear. Host-produced antimicrobial peptides (AMPs) are critical for the integrity of the intestinal epithelial barrier as they prevent the pathogenesis of the enteric microbiota. Here, we report that chronic morphine exposure reduces expression of the antimicrobial peptide, Regenerating islet-derived 3 gamma (Reg3γ), in the ileum resulting in reduced intestinal antimicrobial activity against Gram-positive bacteria, L. reuteri. Fecal samples from morphine-treated mice had reduced levels of the phylum, Firmicutes, concomitant with reduced levels of short-chain fatty acid, butyrate. Fecal microbial transplant (FMT) from morphine-naïve mice restored the antimicrobial activity, the expression of Reg3γ, and prevented the increase in intestinal permeability and the development of antinociceptive tolerance in morphine-dependent mice. Similarly, oral gavage with sodium butyrate dose-dependently reduced the development of antinociceptive tolerance, and prevented the downregulation of Reg3γ and the reduction in antimicrobial activity. The alpha diversity of the microbiome was also restored by oral butyrate in morphine-dependent mice. These data implicate impairment of the antimicrobial activity of the intestinal epithelium as a mechanism by which morphine disrupts the microbiota-gut-brain axis.

The Role of Morphine-Induced Impairment of Intestinal Epithelial Antibacterial Activity in Dysbiosis and its Impact on the Microbiota-Gut-Brain Axis

Recent evidence suggests that chronic exposure to opioid analgesics such as morphine disrupt the intestinal epithelial layer and cause intestinal dysbiosis. Inhibiting opioid-induced dysbiosis can preclude the development of tolerance to opioid-induced antinociception, suggesting an important role of the gut-brain axis in mediating opioid effects. However, the mechanism underlying opioid-induced dysbiosis remains unclear. Host-produced antimicrobial peptides (AMPs) are critical for the integrity of the intestinal epithelial barrier as they prevent the pathogenesis of the enteric microbiota. Here, we report that chronic morphine exposure reduces expression of the antimicrobial peptide, Regenerating islet-derived 3 gamma (Reg3γ), in the ileum resulting in reduced intestinal antimicrobial activity against Gram-positive bacteria, L. reuteri. Fecal samples from morphine-treated mice had reduced levels of the phylum, Firmicutes, concomitant with reduced levels of short-chain fatty acid, butyrate. Fecal microbial transplant (FMT) from morphine-naïve mice restored the antimicrobial activity, the expression of Reg3γ, and prevented the increase in intestinal permeability and the development of antinociceptive tolerance in morphine-dependent mice. Similarly, oral gavage with sodium butyrate dose-dependently reduced the development of antinociceptive tolerance, and prevented the downregulation of Reg3γ and the reduction in antimicrobial activity. The alpha diversity of the microbiome was also restored by oral butyrate in morphine-dependent mice. These data implicate impairment of the antimicrobial activity of the intestinal epithelium as a mechanism by which morphine disrupts the microbiota-gut-brain axis.

Transcriptomics and metabolomics together reveal the underlying mechanism of heroin hepatotoxicity

Researches on heroin are more about addiction and some infectious diseases it causes, but liver fibrosis caused by heroin abuse and the mechanism of heroin hepatotoxicity in addicts are ignored. To explore the mechanism of heroin hepatotoxicity, mice in heroin group were intraperitoneally injected by heroin (10 mg/kg) once a day for 14 consecutive days, while mice in heroin withdraw group underwent another 7 days without heroin administration after the same treatment as heroin group. The levels of alanine aminotransferase （ALT）and aspartate aminotransferase （AST） in serum, as biochemical indexes, were applied to evaluate liver damage. H & E staining and oil red O staining were used to observe the pathological changes of liver. Transcriptomics and metabolomics were applied to detect genes and metabolites in livers. The results of biochemical analysis and pathological examination showed that heroin induced liver damage and lipid loss in mice, and these mice did not return to normal completely after a short-term withdrawal. A total of 511 differential genes and 78 differential metabolites were identified by transcriptomics and metabolomics. These differential genes and metabolites were significantly enriched in pathways like lipid metabolism, arachidonic acid metabolism, glutathione metabolism, TCA cycle. And after undergoing 7-day withdrawal of heroin, most of the above differential genes and metabolites did not return to normal. Our study revealed the hepatotoxicity of heroin and that short-term withdrawal of heroin did not fully restore liver function. In addition, transcriptomics and metabolomics revealed that lipid metabolism and arachidonic acid metabolism may be potential therapeutic targets of heroin hepatotoxicity, providing a basis for the treatment of heroin addiction patients in the future.

Exposure to Morphine and Cocaine Modify the Transcriptomic Landscape in Zebrafish Embryos

Morphine and other opioid analgesics are the drugs of election to treat moderate-to-severe pain, and they elicit their actions by binding to the opioid receptors. Cocaine is a potent inhibitor of dopamine, serotonin, and noradrenaline reuptake, as it blocks DAT, the dopamine transporter, causing an increase in the local concentration of these neurotransmitters in the synaptic cleft. The molecular effects of these drugs have been studied in specific brain areas or nuclei, but the systemic effects in the whole organism have not been comprehensively analyzed. This study aims to analyze the transcriptomic changes elicited by morphine (10 uM) and cocaine (15 uM) in zebrafish embryos. An RNAseq assay was performed with tissues extracts from zebrafish embryos treated from 5 hpf (hours post fertilization) to 72 hpf, and the most representative deregulated genes were experimentally validated by qPCR. We have found changes in the expression of genes related to lipid metabolism, chemokine receptor ligands, visual system, hemoglobins, and metabolic detoxification pathways. Besides, morphine and cocaine modified the global DNA methylation pattern in zebrafish embryos, which would explain the changes in gene expression elicited by these two drugs of abuse.

Folate Status as a Nutritional Indicator among People with Substance Use Disorder; A Prospective Cohort Study in Norway

Substance use disorder (SUD) is associated with poor nutrition. Vitamin B9, or folate, is an important micronutrient for health. The aim of this prospective longitudinal cohort study was to assess serum folate levels among people with SUD and to investigate the impact of factors related to substance use severity on folate status. Participants were recruited from outpatient clinics for opioid agonist therapy (OAT) and municipal health-care clinics for SUD in Western Norway. They were assessed annually, including blood sampling for determination of micronutrient status. Overall, 663 participants with a total of 2236 serum folate measurements were included. A linear mixed model was applied, and measures are presented as β-coefficients with 95% confidence interval (CI). Forty-eight percent (CI: 44−51) of the population had low serum folate levels (s-folate < 10 nmol/L), and 23% (CI: 20−26) were deficient (s-folate < 6.8 nmol/L) at baseline. Sixty percent (CI: 53−65) sustained their poor folate status in at least one subsequent assessment. Except for weekly use of cannabis (mean difference in serum folate [nmol/L]: −1.8, CI: −3.3, −0.25) and alcohol (1.9, CI: 0.15, 3.6), weekly use of no other substance class was associated with baseline differences in serum folate when compared to less frequent or no use. Injecting substances was associated with a reduction in serum folate over time (−1.2, CI: −2.3, −0.14), as was higher dosages of OAT medication (−1.1, CI: −2.2, −0.024). Our findings emphasize the need of addressing nutrition among people with severe SUD.

Effect of chronic opioid use on the hematological and inflammatory markers: A retrospective study from North India

BACKGROUND

Chronic opioid use affects biological functioning implicating the hematopoietic and immune system. It may alter various hematological parameters and inflammatory markers. This study aimed to assess the association of opioid dependence with the hematological parameters and inflammatory markers in the Indian population.

METHODS

A retrospective chart review was done among opioid dependent (ODS) males and healthy controls (HC) who visited the center's laboratory between Jan 2017 and Dec 2018 for hematological investigations. Clinical records reviewed for opioid use details like type, duration, and route of administration. The hematological profile presented as Mean or median. Mann-Whitney U test was used to compare the hematological parameters between the cases and controls.

RESULTS

The study included 191 ODS patients and 123 controls. Among ODS patients, a significant decrease in the levels of hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin and an increase in RBC count and lymphocytes was observed when compared to controls. The inflammatory markers, Neutrophil-Lymphocyte Ratio (NLR) and Platelet-Lymphocyte Ratio, were significantly lower among ODS. Longer duration of opioid use leads to increased NLR among ODS patients. Opioid use by injection did not alter any of the hematological parameters compared to non-injection drug use.

CONCLUSION

Chronic opioid use has a significant effect on the hematopoietic cells. Opioid use for longer durations increases the inflammatory markers suggesting underlying infections.

Glucagon-like peptide-1 receptor agonist, liraglutide, reduces heroin self-administration and drug-induced reinstatement of heroin-seeking behaviour in rats

Drug addiction is a chronic brain disease characterized by the uncontrolled use of a substance. Due to its relapsing nature, addiction is difficult to treat, as individuals can relapse following even long periods of abstinence and, it is during this time, that they are most vulnerable to overdose. In America, opioid overdose has been increasing for decades, making finding new treatments to help patients remain abstinent and prevent overdose deaths imperative. Recently, glucagon-like peptide-1 (GLP-1) receptor agonists have shown promise in reducing motivated behaviours for drugs of abuse. In this study, we test the effectiveness of the GLP-1 analogue, liraglutide (LIR), in reducing heroin addiction-like behaviour, and the potential side effects associated with the treatment. We show that daily treatment with LIR (0.1 mg/kg sc) increases the latency to take heroin, reduces heroin self-administration, prevents escalation of heroin self-administration and reduces drug-induced reinstatement of heroin-seeking behaviour in rats. A 1-h pretreatment time, however, was too short to reduce cue-induced seeking in our study. Moreover, we showed that, while LIR (0.1, 0.3, 0.6 and 1.0 mg/kg sc) supported conditioned taste avoidance of a LIR-paired saccharin cue, it did not elicit intake of the antiemetic kaolin in heroin-naïve or heroin-experienced rats. Further, 0.1 mg/kg LIR did not produce great disruptions in food intake or body weight. Overall, the data show that LIR is effective in reducing heroin taking and heroin seeking at doses that do not cause malaise and have a modest effect on food intake and body weight gain.

Understanding the Role of Orexin Neuropeptides in Drug Addiction: Preclinical Studies and Translational Value

Orexins (also known as hypocretins) are neuropeptides that participate in the regulation of energy metabolism, homeostasis, sleep, feeding, stress responses, arousal, and reward. Particularly relevant to the scope of the present review is the involvement of the orexin system in brain mechanisms that regulate motivation, especially highly motivated behavior, arousal, and stress, making it an ideal target for studying addiction and discovering treatments. Drug abuse and misuse are thought to induce maladaptive changes in the orexin system, and these changes might promote and maintain uncontrolled drug intake and contribute to relapse. Dysfunctional changes in this neuropeptidergic system that are caused by drug use might also be responsible for alterations of feeding behavior and the sleep-wake cycle that are commonly disrupted in subjects with substance use disorder. Drug addiction has often been associated with an increase in activity of the orexin system, suggesting that orexin receptor antagonists may be a promising pharmacological treatment for substance use disorder. Substantial evidence has shown that single orexin receptor antagonists that are specific to either orexin receptor 1 or 2 can be beneficial against drug intake and relapse. Interest in the efficacy of dual orexin receptor antagonists, which were primarily developed to treat insomnia, has grown in the field of drug addiction. Treatments that target the orexin system may be a promising strategy to reduce drug intake, mitigate relapse vulnerability, and restore “normal” physiological functions, including feeding and sleep. The present review discusses preclinical and clinical evidence of the involvement of orexins in drug addiction and possible beneficial pharmacotherapeutic effects of orexin receptor antagonists to treat substance use disorder.

Synaptic Zn2+ potentiates the effects of cocaine on striatal dopamine neurotransmission and behavior

Cocaine binds to the dopamine (DA) transporter (DAT) to regulate cocaine reward and seeking behavior. Zinc (Zn²⁺) also binds to the DAT, but the in vivo relevance of this interaction is unknown. We found that Zn²⁺ concentrations in postmortem brain (caudate) tissue from humans who died of cocaine overdose were significantly lower than in control subjects. Moreover, the level of striatal Zn²⁺ content in these subjects negatively correlated with plasma levels of benzoylecgonine, a cocaine metabolite indicative of recent use. In mice, repeated cocaine exposure increased synaptic Zn²⁺ concentrations in the caudate putamen (CPu) and nucleus accumbens (NAc). Cocaine-induced increases in Zn²⁺ were dependent on the Zn²⁺ transporter 3 (ZnT3), a neuronal Zn²⁺ transporter localized to synaptic vesicle membranes, as ZnT3 knockout (KO) mice were insensitive to cocaine-induced increases in striatal Zn²⁺. ZnT3 KO mice showed significantly lower electrically evoked DA release and greater DA clearance when exposed to cocaine compared to controls. ZnT3 KO mice also displayed significant reductions in cocaine locomotor sensitization, conditioned place preference (CPP), self-administration, and reinstatement compared to control mice and were insensitive to cocaine-induced increases in striatal DAT binding. Finally, dietary Zn²⁺ deficiency in mice resulted in decreased striatal Zn²⁺ content, cocaine locomotor sensitization, CPP, and striatal DAT binding. These results indicate that cocaine increases synaptic Zn²⁺ release and turnover/metabolism in the striatum, and that synaptically released Zn²⁺ potentiates the effects of cocaine on striatal DA neurotransmission and behavior and is required for cocaine-primed reinstatement. In sum, these findings reveal new insights into cocaine's pharmacological mechanism of action and suggest that Zn²⁺ may serve as an environmentally derived regulator of DA neurotransmission, cocaine pharmacodynamics, and vulnerability to cocaine use disorders.

Wounds and Skin and Soft Tissue Infections in People Who Inject Drugs and the Utility of Syringe Service Programs in Their Management

Significance: Opioid use disorder and transition to injection drug use (IDU) are an urgent, nationwide public health crisis. Wounds and skin and soft tissue infections (SSTIs) are common complications of IDU that disproportionately affect people who inject drugs (PWID) and are a major source of morbidity and mortality for this population. Critical Issues: Injections in a nonsterile environment and reusing or sharing needles facilitates bacterial inoculation, with subsequent risk of serious complications such as sepsis, gangrene, amputation, and death. PWID are susceptible to infections with a wide spectrum of organisms beyond common culprits of SSTI, including Clostridium and Bacillus spp., as well as Candida. Recent Advances: Syringe services programs (SSPs) are cost-effective and successful in reducing harms associated with IDU. SSPs provide new equipment to PWID and aid in discarding used equipment. SSPs aim to reduce the risks of unhygienic injecting practices, which are associated with transmission of infections and blood-borne pathogens. Future Directions: Concurrently run SSPs and wound care clinics are uniquely positioned to facilitate care to PWID. Providing new, sterile equipment as well as early wound care intervention can reduce morbidity and mortality as well as health care expenditures by reducing the number of SSTI and injection-related wounds that require hospital admission. Establishment of wound care clinics as part of an SSP represents an untapped potential to reduce harm.

Sex Differences in Behavioral and Brainstem Transcriptomic Neuroadaptations following Neonatal Opioid Exposure in Outbred Mice

The opioid epidemic led to an increase in the number of neonatal opioid withdrawal syndrome (NOWS) cases in infants born to opioid-dependent mothers. Hallmark features of NOWS include weight loss, severe irritability, respiratory problems, and sleep fragmentation. Mouse models provide an opportunity to identify brain mechanisms that contribute to NOWS. Neonatal outbred Swiss Webster Cartworth Farms White (CFW) mice were administered morphine (15 mg/kg, s.c.) twice daily from postnatal day 1 (P1) to P14, an approximation of the third trimester of human gestation. Female and male mice underwent behavioral testing on P7 and P14 to determine the impact of opioid exposure on anxiety and pain sensitivity. Ultrasonic vocalizations (USVs) and daily body weights were also recorded. Brainstems containing pons and medulla were collected during morphine withdrawal on P14 for RNA sequencing. Morphine induced weight loss from P2 to P14, which persisted during adolescence (P21) and adulthood (P50). USVs markedly increased at P7 in females, emerging earlier than males. On P7 and P14, both morphine-exposed female and male mice displayed hyperalgesia on the hot plate and tail-flick assays, with females showing greater hyperalgesia than males. Morphine-exposed mice exhibited increased anxiety-like behavior in the open-field arena on P21. Transcriptome analysis of the brainstem, an area implicated in opioid withdrawal and NOWS, identified pathways enriched for noradrenergic signaling in females and males. We also found sex-specific pathways related to mitochondrial function and neurodevelopment in females and circadian entrainment in males. Sex-specific transcriptomic neuroadaptations implicate unique neurobiological mechanisms underlying NOWS-like behaviors.

Lipid profile dysregulation in opium users based on Fasa PERSIAN cohort study results

One of the main health problems in many societies is the increased opium abuse, which was found to be correlated with many problems like cardiovascular disease. This study aimed to evaluate the correlation of opium use with blood lipoproteins as the risk factor of CVD. This was a cross-sectional study conducted on participants of the first phase of the PERSIAN Cohort study who were aged between 35 and 70 years old. Demographic characteristics; history of smoking, alcohol, and opium consumption; medical history; and medications were asked and the related checklists were filled out. The levels of physical activity and fat intake were also registered. As well, lipoprotein profiles were investigated by blood sampling. The linear and logistic regression was used to analyze the relationship between opium and lipid profile and the statistical significant level was considered as < 0.05. Among 9300 participants with a mean age of 48.06 ± 9.44 years old, 49.6% of them were men. About 24.1% of the participants used opium. In the linear regression models, unlike TG (β = 2.2, p = 0.36), total cholesterol (β = − 2.5, p = 0.02), LDL (β = − 2.0, p = 0.04), and HDL (β = − 1.0, p = 0.04) were significantly lower in people who used opium compared to the others. In the logistic regression models, abnormal level of LDL (OR = 0.78, p = 0.003) and total cholesterol (OR = 0.82, p = 0.008) were less in people who used opium compared to the others. This study showed that there is a correlation between opium usage and lower levels of total cholesterol and LDL; however, the lower level of HDL in normal range was seen in opium users. Considering the current evidences, most of them showed the increased risks of ischemic heart disease, heart attack, hypertension, cerebrovascular disease, and cancer in opium users. Therefore, Healthcare providers and patients should be noticed about the deleterious effects of opium consumption on various vascular events. In addition, it is necessary for managers and policy makers of the health care system to take the necessary measures to raise the level of awareness and health literacy of the general public about the high-risk side effects of opium use and to take necessary and effective strategies to prevent and reduce its use.

People who use drugs in rehabilitation, from chaos to discipline: Advantages and pitfalls: A qualitative study

Evidence-based models emphasizing on lifestyle behaviours for the treatment of drug use is still in its infancy. The development of multicomponent effective drug use intervention programs as part of health promotion is crucial to decrease risk of relapse. This study aims at exploring the lifestyle practices including dietary intake, physical activity and sleep of people who use drugs undergoing residential rehabilitation treatment in Lebanon with its perceived benefits and pitfalls. A purposive sample of 18 males and 9 females at different stages of recovery from drug use in rehabilitation centers participated in the qualitative discussions. The six phases thematic analysis revealed three themes: chaotic lifestyle, structuredlifestyle, benefits and pitfalls, and suggestions for making rehabilitation a better experience. Participants discussed their chaotic lifestyle during addiction with poor food intake, disrupted sleep and low physical activity moving to a more disciplined routine enforcing normality in lifestyle practices with social and professionlprofessional support. The early phases of treatment were marked with increased food intake and weight gain perceived as a health indicator and the sole divergent from drugs, moving towards more structured meals and efforts to lose weight in later stages. Lack of variety of Physical activity programs taking into consideration the motivational differences among the participants was also highlighted. Measures for improving rehabilitation services in terms of promoting healthy eating behaviours and environmental control were thoroughly addressed. These findings shed the light on the challenges faced in maintaining a healthy lifestyle in rehabilitation centers and the necessities of addressing them to improve the overall rehabilitation experience, prevent relapse and inform the development of future targeted intervention programs tackling all aspects of behavioural changes.

Nutritional status and eating habits of people who use drugs and/or are undergoing treatment for recovery: a narrative review

A comprehensive overview is presented of the nutritional issues faced by people who use drugs or are undergoing treatment for recovery. Chronic substance use affects a person’s nutritional status and body composition through decreased intake, nutrient absorption, and dysregulation of hormones that alter the mechanisms of satiety and food intake. Anthropometrics alone is not the best indicator of nutritional status, because this population has hidden deficiencies and disturbed metabolic parameters. Socioeconomic factors (eg, higher education, higher income, presence of a partner, living at home) positively affect nutritional status. Scarce available data on users undergoing treatment indicate improvement in anthropometric and metabolic parameters but with micronutrient intake remaining suboptimal. Weight gain is noted especially among women who use drugs and potentially increases their risk of relapse. Finally, specific amino acids and omega-3 fatty acids are promising in decreasing relapse and improving mental health during treatment; however, additional high-quality studies are needed. Nutrition intervention for people who use drugs or are undergoing treatment for recovery is underused; comprehensive programs addressing this population’s unique needs are necessary. Future research will identify which components are needed.

Dental caries and periodontal disease among people who use drugs: a systematic review and meta-analysis

BACKGROUND

The aim of our study was to perform a systematic review of the literature and meta-analysis in order to investigate relationship between drug use and oral health.

METHODS

We searched for studies in English published before July 1, 2019 on PsycINFO, PubMed, SciELO, Scopus, and Web of Science. We assessed the relationship between drug use (methamphetamines, heroin; opiates; crack, cocaine and cannabis as dependent variables) and reported tooth loss, periodontal disease, or decayed, missing, and filled teeth index as an independent variable. The data were analyzed using Stata 12.0 software.

RESULTS

We initially identified 1836 potential articles (with 1100 duplicates) and screened the remaining 736 titles and abstracts, comprising 54 studies. In the next step, we evaluated the full-texts; 44 studies were excluded, accordingly. In total, we included 10 publications in the meta-analysis. Drug type was associated with periodontal disease (OR 1.44; 95% CI 0.8-2.6) and pooled estimates showed that type of drug used increased the odds of the number of decayed, missed and filled teeth (DMFT) (OR 4.11; 95% CI 2.07-8.15) respectively.

CONCLUSIONS

The analytical challenges of segregating the impact of individual drug types on oral health diseases mean that investigations on the direct relationship between oral health status and drug use are limited. Developing programs to improve potential confounding with various substances and addressing the dental health needs of people who use drugs is vital if we are to improve their overall quality of life.

Comparing nutrient intake and body weight status amongst adolescent substance users, institutionalised abstainers and never users

Background

Improved nutrition intake in drug rehabilitation programmes enhances quality sobriety and prevents relapses. However, little is known about the nutritional status of substance users and institutionalised abstainers. Previous nutritional studies have mainly focused on methamphetamine, whereas ketamine has not been investigated despite its popularity amongst adolescents.

Objectives

To compare nutrient intake and underweight status amongst three groups of adolescents –current substance users, institutionalised abstainers and never users (controls) – and examine the association between ketamine use and nutrient intake.

Design

This is a cross-sectional questionnaire survey which was conducted using face-to-face interview. Substance users (n = 202) and never users (n = 100) were invited through the outreach social workers of three non-government organisations. Abstainers (n = 50) were recruited from three drug rehabilitation centres. Nutrient intake was assessed through two 24-h recalls. Other information collected included anthropometrics, socio-demographic characteristics and substance type used over the previous month.

Results

Only 20.8 and 15.9% of male and female substance users met the daily energy requirements. Male users were less likely to meet the recommended intake of energy [odds ratio (OR) = 0.37] and protein (OR = 0.10) than controls. Overall, abstainers had better intake of beneficial nutrients than substance users. However, abstainers were more likely to overconsume harmful nutrients, such as cholesterol and sodium. Regarding weight status, female substance users (56.1%) were more likely to be underweight than abstainers (14.8%) (OR = 8.85). Amongst underweight female substance users, 52.2% were still trying to lose more weight. Moreover, ketamine users tended to have lower intake of nutrients from animal sources than the users of other drugs.

Conclusions

Adolescent substance users are at risk of energy and nutrient inadequacy. Misconceptions about body weight are disseminating amongst them. The study findings provide valuable information for frontline workers taking care of young substance users and for institutions providing residential rehabilitation programmes.

Potential disease burden of patients with substance abuse undergoing major abdominal surgery: A propensity score-matched analysis

BACKGROUND

Over 19 million Americans have a substance abuse disorder. The current study sought to characterize the relationship between substance abuse with in-hospital outcomes following major, elective abdominal surgery.

METHODS

The Nationwide Inpatient Sample was used to identify patients who underwent major abdominal surgery between 2007 to 2014. Patients with preoperative substance abuse, including alcohol, opioids, and non-opioid drugs, were identified. Propensity score matching was used to examine the association of substance abuse with perioperative outcomes.

RESULTS

Among 301,659 patients, 7,925 patients (2.6%) had a history of substance abuse. Pancreatectomy was the surgical procedure with the highest proportion of patients with substance abuse history (n = 844, 4.7%). Compared with patients without a substance abuse history, patients with a substance abuse history were more likely to be younger (median age, 60 years [interquartile range (IQR) 52-69] vs 63 years [IQR 52-72]), male (n = 5,438, 67.5% vs n = 132,961, 54.7%), and be in the lowest income category (n = 2,062, 26% vs n = 64,345, 21.9%) (all P < .001). On propensity score matching, substance abuse was associated with increased odds ratio of experiencing a complication (odds ratio [OR] 1.68, 95% confidence interval [CI] 1.55-1.82), non-home discharge (OR 1.95, 95% CI 1.76-2.16), extended length of stay (OR 1.88, 95% CI 1.76-2.02), and higher expenditure (OR 1.62, 95% CI 1.49-1.77). Stratified by the type of substance abuse, patients with history of alcohol (OR 1.57, 95% CI 1.44-1.71) and drug abuse (OR 1.26, 95% CI 1.14-1.39) were more likely to experience a complication, whereas only history of alcohol abuse was associated with higher odds ratio of in-hospital mortality (OR 1.38, 95% CI 1.07-1.79) (all P < .05).

CONCLUSION

Up to 1 in 50 patients undergoing complex abdominal surgery had a substance abuse history. History of substance abuse was associated with an increased risk of adverse perioperative outcomes and higher healthcare expenditures.

Oral Health Behavior and Treatment Needs among Drug Addicts and Controls in Amritsar District: A Case-controlled Study

Background:

Substance and drug abuse is associated with severe psychosocial problems, violence and health complications.

Aims:

The aim of the study was to evaluate and compare the oral hygiene status and sugar eating patterns among drug addicts with their age, gender and socio-economic status matched controls.

Settings and Design:

The present study comprised of two groups-Group A comprised of 100 drug addicts and Group B included 100 controls. The study sample were interviewed and subjected to a comprehensive intra-oral examination.

Methods and Material:

Standardized methods of evaluation were performed using mouth mirror, dental probe, explorer and WHO probe.

Statistical Analysis:

The data was subjected to statistical analysis using Chi Square test and student t-test.

Results and Conclusions:

CPITN index revealed bleeding in 56% addicts and calculus in 20% addicts. The mean DMFT of group A was 5.71 as compared to 2.45 in group B. The frequency of sugar consumption was found to be high in addicts as compared to the controls. Significant P values (< 0.001) of DMFT index, periodontal status and frequency of sugar consumption were obtained on statistical analysis. The caries status was found to be poor in addicts, but the periodontal treatment needs were similar for both group A and B. Oral health promotion should be undertaken in drug rehabilitation centers for overall success of withdrawl treatment.

Active Brazilian crack cocaine users: nutritional, anthropometric, and drug use profiles

Objective:

To evaluate the nutritional status of crack users and to analyze its correlation with drug use profiles.

Methods:

Cross-sectional study with 108 crack users. Anthropometric data were assessed through body mass index (BMI) and bioimpedance (BIA) measurements. A blood test to analyze hematocrit, hemoglobin, glucose, and lipid profiles was also performed. Crack use was determined through a standardized interview.

Results:

Based on BMI and BIA, most individuals were eutrophic (about 70%). Regarding hematological parameters, we found that hemoglobin and hematocrit levels were below normal for 32.4 and 30.6% of patients, respectively. Considering normal parameters, a large part of the sample (60.2%) had low levels of HDL cholesterol and high levels of triglycerides (38%). There were no significant correlations between drug profile and nutritional variables.

Conclusion:

This is a pioneering study that examines the nutritional status of crack users. Our results showed that most crack users present normal anthropometric findings and the prevalence of underweight is low. However, blood analysis showed changes and a specific type of malnutrition.

Independent associations and effect modification between lifetime substance use and recent mood disorder diagnosis with household food insecurity

Poor mental health and substance use are associated with food insecurity, however, their potential combined effects have not been studied. This study explored independent associations and effect modification between lifetime substance use and mood disorder in relation to food insecurity. Poisson regression analysis of data from British Columbia respondents (n = 13,450; 12 years+) in the 2007/08 Canadian Community Health Survey was conducted. Measures included The Household Food Security Survey Module (7.3% food insecure), recent diagnosis of a mood disorder (self-reported; 9.5%), lifetime use of cannabis, cocaine/crack, ecstasy, hallucinogens, and speed, any lifetime substance use, sociodemographic covariates, and the interaction terms of mood disorder by substance. For those with recent diagnosis of a mood disorder the prevalence of lifetime substance use ranged between 1.2 to 5.7% and were significantly higher than those without recent mood disorder diagnosis or lifetime use of substances (p’s < 0.05). For respondents with a recent mood disorder diagnosis or who used cannabis, food insecurity prevalence was higher compared to the general sample (p < 0.001); prevalence was lower for cocaine/crack use (p < 0.05). Significant effect modification was found between mood disorder with cannabis, ecstasy, hallucinogen and any substance use over the lifetime (PRs 0.51 to 0.64, p’s 0.022 to 0.001). Independent associations were found for cocaine/crack and speed use (PRs 1.68, p’s < 0.001) and mood disorder (PRs 2.02, p’s < 0.001). Based on these findings and the existing literature, future study about coping and resilience in the context of substance use, mental health, and food insecurity may lead to the development of relevant interventions aimed at mental well-being and food security.

Food Insecurity in HIV-Hepatitis C Virus Co-infected Individuals in Canada: The Importance of Co-morbidities

While research has begun addressing food insecurity (FI) in HIV-positive populations, knowledge regarding FI among individuals living with HIV-hepatitis C virus (HCV) co-infection is limited. This exploratory study examines sociodemographic, socioeconomic, behavioral, and clinical factors associated with FI in a cohort of HIV-HCV co-infected individuals in Canada. We analyzed longitudinal data from the Food Security and HIV-HCV Co-infection Study of the Canadian Co-infection Cohort collected between November 2012-June 2014 at 15 health centres. FI was measured using the Household Food Security Survey Module and classified using Health Canada criteria. Generalized estimating equations were used to assess factors associated with FI. Among 525 participants, 59 % experienced FI at their first study visit (baseline). Protective factors associated with FI (p < 0.05) included: enrolment at a Quebec study site (aOR: 0.42, 95 % CI: 0.27, 0.67), employment (aOR: 0.55, 95 % CI: 0.35, 0.87), and average personal monthly income (aOR per $100 CAD increase: 0.98, 95 % CI: 0.97, 0.99). Risk factors for FI included: recent injection drug use (aOR: 1.98, 95 % CI: 1.33, 2.96), trading away food (aOR: 5.23, 95 % CI: 2.53, 10.81), and recent experiences of depressive symptoms (aOR: 2.11, 95 % CI: 1.48, 3.01). FI is common in this co-infected population. Engagement of co-infected individuals in substance use treatments, harm reduction programs, and mental health services may mitigate FI in this vulnerable subset of the HIV-positive population.

Oral health effects, brushing habits and management of methamphetamine users for the general dental practitioner

BACKGROUND

Methamphetamine is a synthetic drug commonly abused in South Africa and is highly addictive. Users have a higher prevalence of dental caries compared to non-users and the classical caries pattern found in methamphetamine users is termed 'meth mouth'. The increased consumption of soft drinks and the absence of saliva are the main risk factors for 'meth mouth'.

AIM

To determine the oral health status of individuals using methamphetamine.

METHOD

A cross-sectional study was conducted on a convenience sample of 308 self-reported methamphetamine users at 22 specialised substance addiction treatment centres in the Western Cape, South Africa.

RESULTS

There was a significant difference in tooth brushing frequency when using methamphetamine (p = 0.0000022; χ(2) = 23.84; OR = 3.25). The mean decayed, missing and filled teeth score was ten and there was an association between the mean number of decayed teeth and the duration of drug addiction (p = 0.0071; χ(2) = 12.07). Users who were using methamphetamine for less than four years had fewer missing teeth compared to those who were using methamphetamine for more than four years.

CONCLUSIONS

When methamphetamine abuse is detected, the dentist can play a key role in early management of drug addiction by referring the patient to specialised substance addiction treatment centres. In addition, by restoring the dental appearance, users may regain their self-esteem and improve their oral health quality of life.

Non-medical use of olanzapine by people on methadone treatment

Aims and method We examined non-medical use (NMU) of olanzapine among adults on methadone treatment. Information was collected on patient demographics and NMU of olanzapine. The Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) was administered to assess risk among current users of olanzapine. Results Ninety-two clients participated and 30% reported lifetime history of NMU of olanzapine. Nine people reported doses of 30 mg or higher on a typical day of use, with three typically using 100 mg. The most common reasons for use were to relieve anxiety and to aid sleep, but a quarter used it to 'get stoned'. Eleven participants (12%) reported NMU of olanzapine in the preceding month. Eight completed the ASSIST with four scoring in the high-risk zone. Clinical implications Self-medication is the dominant motivator for NMU of olanzapine, but hedonic motivations also occur. A small minority show features of dependency. All doctors should be aware of the potential NMU of olanzapine, especially among patients with history of addiction.

Differential Effects of Prenatal Protein Malnutrition and Prenatal Cocaine on Radial Arm Maze Performance in Adult Male Rats

The effects of prenatal cocaine and protein malnutrition were examined on acquisition of the radial arm maze in adult male Sprague-Dawley rats whose mothers were provided with a 6% casein, a 25% casein or a standard chow diet and cocaine (30mg/kg) or saline injections beginning 5 weeks prior to mating and continuing to parturition. Rats were tested using an 8-arm radial maze with 4 baited arms and were required to collect all 4 food pellets within 5 min to complete a trial. Subjects were tested for 1 trial/day until they met criterion for successful acquisition of the task. Criterion was attained when the rat collected 3 out of the 4 food pellets within their first 4 arm entries within a trial (while still completing the trial) with this level of performance being maintained for 3 consecutive trials. The results showed dissociation between the effects of prenatal protein malnutrition and prenatal cocaine. Prenatally protein malnourished adult male rats required a greater number of trials to criterion, made more reference memory (but not working memory) errors, and required a longer time to complete each trial when compared with control males. However, rats with prenatal cocaine exposure showed no significant impairments in the radial arm maze. These results contrast with our previous findings using the Morris maze task in which adult male subjects exhibited impaired acquisition following prenatal cocaine while there were no effects following prenatal protein malnutrition. Thus, the radial arm maze and water maze procedures appear to engage different processes that are differentially sensitive to the prenatal insults.

Associations Between Body Weight Status and Substance Use Among African American Women in Baltimore, Maryland: The CHAT Study

BACKGROUND

Studies on associations between body weight status and specific substance use have provided conflicting findings.

OBJECTIVES

This paper investigated the association between substance use and body weight status among African American women.

METHODS

We analyzed the data from 328 African American women who were enrolled in a HIV prevention intervention in Baltimore, MD, USA, in order to investigate the association between substance use and their body weight status. Participants' anthropometry was measured by trained research staff. Substance use information was collected via self-administered and interviewer-administered questionnaires.

RESULTS

About 33.4% were classified as normal/underweight, 24.2% overweight, and 42.4% obese. Compared to overweight (38.5%) and obese (29.2%) participants, the normal/underweight women had significantly higher prevalence of drug use (52.8%) (χ(2)= 14.11, p < 0.05). BMI was significantly negatively associated with current heroin use (t = -2.21, p < 0.05). The risk of being overweight and obesity was lower among active marijuana (z = -2.05, p < 0.05) and heroin users (z = -1.91, p < 0.10) than among non-marijuana/non-heroin users. Heroin smokers had lower body weight (t = -3.02, p < 0.05) and BMI (t = -2.47, p < 0.05) than non-heroin smokers. The decrease in BMI appeared to be greater among more frequent (≥once/day) heroin users (t = -2.39, p <0.05) as compared to the less frequent heroin users (

CONCLUSIONS

The results are comparable to existing findings. Active marijuana and heroin users were less likely to be overweight and obese compared to their counterparts. The impact of substance use on body weight status differed by the frequency and route of administration.

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Key Words

• African American
• Obesity
• overweight
• substance use
• women

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MESH Headings

• Baltimore
• Body Mass Index
• Body Weight
• Female
• Humans
• Overweight
• United States

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Grants

• R01 MH066810 NIMH NIH HHS
• P30 AI094189 NIAID NIH HHS
• K99 AA020782 NIAAA NIH HHS
• K01 MH096611 NIMH NIH HHS
• R00 AA020782 NIAAA NIH HHS

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Affiliation(s)

Ji Li Department of Health, Behavior and Society, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
Cui Yang Department of Health, Behavior and Society, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
Melissa Davey-Rothwell Department of Health, Behavior and Society, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
Carl Latkin Department of Health, Behavior and Society, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA

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Zinc involvement in opioid addiction and analgesia--should zinc supplementation be recommended for opioid-treated persons?

INTRODUCTION

Zinc chelators were shown to facilitate some opioid-withdrawal signs in animals. Zinc deficiency, which affects more than 15% the world's population, is also common among opioid consumers and opioid-treated animals exhibit misbalances of zinc distribution.

AIM

The present study focuses on how zinc ions interfere with opioid dependence/addiction and analgesia, trying to preliminary discuss if zinc supplementation in opioid-users should be recommended in order to reduce the risk of addiction.

METHODS

All relevant literature was searched up to April 2015. The search was performed using the term "zinc" plus combinations of following terms: "opioid receptors", "opioid" or representatives of this class, "addiction", "dependence", "analgesia", and "pain". Human, animal, in vitro studies and reviews were including.

RESULTS

Both human and animal studies revealed decreased serum zinc under opioid-administration conditions, attributed mainly to increased urinary elimination (humans) or redistribution (animals). Moreover, animal studies revealed decreased brain zinc levels in morphine-treated animals, with increased zinc hepatic levels, but also an enhancement of endogenous opioid system activity and a possible reduction of morphine withdrawal by zinc. In vitro studies revealed reduction of opioid ligands binding to receptors by zinc. However, the very few in vivo animal studies on opioid analgesia revealed controversial results, as zinc demonstrated clear analgesic effect, but zinc associated to opioids doesn't result in a potentiation of the analgesic effect.

CONCLUSION

Zinc dietary supplementation in patients treated with opioids for cancer-related chronic pain should be considered, due to the high incidence of zinc deficiency, also well-documented in opioid consumers. The low toxicity of orally-administered zinc also pleads for this idea. The main contra-argument to zinc administration in opioid-treated persons is related to the way zinc influences opioid-induced analgesia.

Once is too much: conditioned aversion develops immediately and predicts future cocaine self-administration behavior in rats

Rats emit aversive taste reactivity (TR) behavior (i.e., gapes) following intraoral delivery of a cocaine-paired taste cue and greater conditioned aversive TR at the end of training predicts greater drug-seeking and taking. Here, we examined the development of this conditioned aversive TR behavior on a trial-by-trial basis in an effort to determine when the change in behavior occurs and whether early changes in this behavior can be used to predict later drug taking. The results show that conditioned aversive TR to a cocaine-paired cue occurs very early in training (i.e., following as few as 1-2 taste-drug pairings) and, importantly, that it can be used to predict later drug seeking and drug taking in rats.

Effectiveness of Educational Programs on Nutritional Behavior in Addicts Referring to Baharan Hospital, Zahedan (Eastern of IR Iran)

Background:

There are many factors which affect nutritional status of addicted such as lack o f knowledge, incorrect attitude toward modification of food pattern, and careless to food intake.

Objectives:

The aim of this study was to determine the effectiveness of educational program on nutritional behavior in addicts referring to Baharan hospital in Zahedan.

Patients and Methods:

Thirty-six addict patients were selected randomly. After recording general demographic data of patients, nutritional behaviors were determined. To determine the effectiveness of nutritional educational program, pre and post-tests were performed. Evaluation of nutritional behavior was determined as poor, fair and satisfactory levels. Statically analysis was performed by SPSS software.

Results:

Most addict patients had a medium level of education. Improvement in knowledge, attitude and practice (KAP) of patients after intervention was observed as follows; decreasing KAP in poor level (2.8% vs. 30.6%), (3% vs. 50%), (25% vs. 80.6%), respectively; also, increasing KAP in fair level (7% vs. 55.6 %), (15% vs. 15%), (19% vs. 7%), respectively and increasing KAP in satisfactory levels (77.8% vs. 13.8%), (50% vs. 8.3%), and (22.2% vs. 0%), respectively (P < 0.0001). There was a significant difference regarding the grade of KAP in patients based on gender, marital status, and education level after education (P < 0.0001).

Conclusions:

This study showed that nutritional KAP was improved in addicts. After intervention, there was a significant difference in the score of knowledge, attitude, and practice scores in patients in the current study. KAP was improved in patients after intervention including; decreased KAP in poor level and increased KAP in fair and satisfactory levels. This finding indicates that addict patients would like to modify their life style.

Involuntary weight loss

Involuntary weight loss remains an important and challenging clinical problem, with a high degree of morbidity and mortality. Because of the frequency of finding a serious underlying diagnosis, clinicians must be thorough in assessment, keeping in mind a broad range of possible causes. Although prediction scores exist, they have not been broadly validated; therefore, clinical judgment remains ever essential.

Is low BMI associated with specific drug use among injecting drug users?

Body mass index (BMI) of a sample of people who regularly inject drugs (N = 781) was examined to gauge the impact of specific types of drug use. Cross-sectional interviews were undertaken in 2010 as part of a national monitoring program funded by the Australian Government. Latent class analysis identified three groups of drug users, with heroin users at 3.4 times the risk of being underweight compared with amphetamine users, and amphetamine users were at almost twice the odds of being obese compared with lower level morphine users. Nutrition should play a part in harm minimization.

Illicit drug use and cardiometabolic disease risk: an analysis of 2005-2008 National Health and Nutrition Examination Survey data

PURPOSE

To explore the association between illicit drug use (IDU) and cardiometabolic disease risk factors (CDRF) in a nationally representative sample of adults.

METHODS

The 2005-2008 National Health and Nutrition Examination Surveys data from 20- to 45-year-old adults (n = 8738) were utilised to analyze the relationship between IDU (ever used, repeated use and current use) and CDRF (hyperlipidemia, hyperinsulinemia, hypertension, elevated C-reactive protein, body mass index, waist circumference and cigarette use) via chi square and logistic regression analyses. Age, gender, race/ethnicity, education level, poverty to income ratio (PIR), and alcohol use were included as confounders in the models.

RESULTS

Individuals who reported drug use (DU) at least once in lifetime were more likely to have CDRF than non-DU (NDU) (OR = 1.3, p = 0.004). Females with DU, IDU at least once in lifetime, and with repeated IDU were about 1.5 times more likely than their NDU counterparts to have CDRF (p < 0.0001, p = 0.02, p = 0.02, respectively).

CONCLUSION

Results from this study suggest that healthcare professionals should be aware that patients with a history of DU may be at heightened risk for cardiometabolic disease. Females in particular have a heightened cluster of CDRF across drug-use categories.

Relationship between food insecurity and mortality among HIV-positive injection drug users receiving antiretroviral therapy in British Columbia, Canada

Objectives

Little is known about the potential impact of food insecurity on mortality among people living with HIV/AIDS. We examined the potential relationship between food insecurity and all-cause mortality among HIV-positive injection drug users (IDU) initiating antiretroviral therapy (ART) across British Columbia (BC).

Methods

Cross-sectional measurement of food security status was taken at participant ART initiation. Participants were prospectively followed from June 1998 to September 2011 within the fully subsidized ART program. Cox proportional hazard models were used to ascertain the association between food insecurity and mortality, controlling for potential confounders.

Results

Among 254 IDU, 181 (71.3%) were food insecure and 108 (42.5%) were hungry. After 13.3 years of median follow-up, 105 (41.3%) participants died. In multivariate analyses, food insecurity remained significantly associated with mortality (adjusted hazard ratio [AHR] = 1.95, 95% CI: 1.07–3.53), after adjusting for potential confounders.

Conclusions

HIV-positive IDU reporting food insecurity were almost twice as likely to die, compared to food secure IDU. Further research is required to understand how and why food insecurity is associated with excess mortality in this population. Public health organizations should evaluate the possible role of food supplementation and socio-structural supports for IDU within harm reduction and HIV treatment programs.

When a good taste turns bad: Neural mechanisms underlying the emergence of negative affect and associated natural reward devaluation by cocaine

An important feature of cocaine addiction in humans is the emergence of negative affect (e.g., dysphoria, irritability, anhedonia), postulated to play a key role in craving and relapse. Indeed, the DSM-IV recognizes that social, occupational and/or recreational activities become reduced as a consequence of repeated drug use where previously rewarding experiences (e.g., food, job, family) become devalued as the addict continues to seek and use drug despite serious negative consequences. Here, research in the Carelli laboratory is reviewed that examined neurobiological mechanisms that may underlie these processes using a novel animal model. Oromotor responses (taste reactivity) were examined as rats learned that intraoral infusion of a sweet (e.g., saccharin) predicts impending but delayed access to cocaine self-administration. We showed that rats exhibit aversive taste reactivity (i.e., gapes/rejection responses) during infusion of the sweet paired with impending cocaine, similar to aversive responses observed during infusion of quinine, a bitter tastant. Critically, the expression of this pronounced aversion to the sweet predicted the subsequent motivation to self-administer cocaine. Electrophysiology studies show that this shift in palatability corresponds to an alteration in nucleus accumbens (NAc) cell firing; neurons that previously responded with inhibition during infusion of the palatable sweet shifted to excitatory activity during infusion of the cocaine-devalued tastant. This excitatory response profile is typically observed during infusion of quinine, indicating that the once palatable sweet becomes aversive following its association with impending but delayed cocaine, and NAc neurons encode this aversive state. We also review electrochemical studies showing a shift (from increase to decrease) in rapid NAc dopamine release during infusion of the cocaine-paired tastant as the aversive state developed, again, resulting in responses similar to quinine infusion. Collectively, our findings suggest that cocaine-conditioned cues elicit a cocaine-need state that is aversive, is encoded by a distinct subset of NAc neurons and rapid dopamine signaling, and promotes cocaine-seeking behavior. Finally, we present data showing that experimentally induced abstinence (30 days) exacerbates this natural reward devaluation by cocaine, and this effect is correlated with a greater motivation to lever press during extinction. Dissecting the neural mechanisms underlying these detrimental consequences of addiction is critical since it may lead to novel treatments that ameliorate negative affective states associated with drug use and decrease the drive (craving) for the drug. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.

A drug-paired taste cue elicits withdrawal and predicts cocaine self-administration

Addiction is a chronic disease where periods of abstinence are riddled with instances of craving, withdrawal, and eventual relapse to escalated drug use. Cues previously associated with drug use can have a deleterious effect on this cycle by precipitating withdrawal symptoms. Here we focus specifically on the relationship between avoidance of a drug-paired taste cue and the ability of the drug-paired cue to elicit withdrawal and, ultimately, drug seeking and taking. We used a rat model of drug addiction and naloxone-induced loss of body weight to test whether a taste cue elicits withdrawal in anticipation of drug availability. Experiment 1 investigated the ability of a taste cue to elicit signs of withdrawal when it predicted experimenter-administered morphine (15 mg/kg, i.p.). In Experiment 2, a saccharin taste cue was paired with the opportunity to actively self-administer cocaine (0.167 mg/infusion, i.v.). The results show that presentation of a morphine- or cocaine-paired taste cue is sufficient to elicit naloxone-induced withdrawal symptoms, and greater withdrawal predicts greater cocaine self-administration in rats.

The effect of nucleus accumbens lesions on appetite, sexual function, and nicotine dependence in recovering heroin addicts

The nucleus accumbens (NAc) is a key part of the neural circuitry that creates reward, pleasure and motivation that facilitates human feeding, sexual and smoking behaviors. In the brain reward system, the NAc is a crucial component responsible for natural and drug-induced reinforcement behaviors. Yet it is unclear whether NAc is indispensible for all reward behaviors in human beings. The present study aimed to investigate the long-term effects of NAc ablation on sexual function, appetite, and nicotine dependence level in chronic heroin users. Eighteen former heroin-dependent patients (male) with bilateral NAc ablation via stereotactic radiofrequency surgery for alleviating drug psychological dependence were recruited. Their postoperative time ranged from 12 to 103 months. All subjects received MRI scans for assessing the accuracy of the lesion site. Evaluation of appetite, sexual function, and nicotine dependence were measured using the Simplified Nutrition Appetite Questionnaire, the Brief Sexual Function Inventory, and the Fagerström Test for Nicotine Dependence, respectively. After precluding the potential confounding variables, such as drug use (dosage and duration), post-operation duration, age, body-weight, marital status and education level, ANOVA with repeated measures revealed that the NAc ablation improved the patients’ appetite, sexual drive and sexual satisfaction. Yet there was no change in male erectile function, ejaculatory function, or nicotine dependence levels compared to the preoperative. These may suggest that although NAc is a key part of the neural circuitry, the NAc surgical lesions left the fundamental aspects of natural and drug-induced reinforcement and motivation almost intact.

Sex differences in selecting between food and cocaine reinforcement are mediated by estrogen

Cocaine-dependent women, relative to their male counterparts, report shorter cocaine-free periods and report transiting faster from first use to entering treatment for addiction. Similarly, preclinical studies indicate that female rats, particularly those in the estrus phase of their reproductive cycle, show increased operant responding for cocaine under a wide variety of schedules. Making maladaptive choices is a component of drug dependence, and concurrent reinforcement schedules that examine cocaine choice offers an animal model of the conditions of human drug use; therefore, the examination of sex differences in decision-making may be critical to understanding why women display a more severe profile of cocaine addiction than men. Accordingly, we assessed sex and estrous cycle differences in choice between food (45 mg grain pellets) and intravenous cocaine (0.4 or 1.0 mg/kg per infusion) reinforcement in male, female (freely cycling), and ovariectomized (OVX) females treated with either estrogen benzoate (EB; 5 μg per day) or vehicle. At both cocaine doses, intact female rats choose cocaine over food significantly more than male rats. However, the estrous cycle did not impact the level of cocaine choice in intact females. Nevertheless, OVX females treated with vehicle exhibited a substantially lower cocaine choice compared with those receiving daily EB or to intact females. These results demonstrate that intact females have a greater preference for cocaine over food compared with males. Furthermore, this higher preference is estrogen-dependent, but does not vary across the female reproductive cycle, suggesting that ovarian hormones regulate cocaine choice. The present findings indicate that there is a biological predisposition for females to forgo food reinforcement to obtain cocaine reinforcement, which may substantially contribute to women experiencing a more severe profile of cocaine addiction than men.

Plausible impact of dietary habits on reduced blood sugar in diabetic opium addicts with coronary artery disease

BACKGROUND

The effect of opium on glycemic control in diabetics is a controversial issue, as some studies have shown glucose lowering effect of opium in diabetes while the results of other studies do not support this idea. The possible role of opioid peptides in the regulation of food intake has been previously investigated. However, there is no data available about relationship between opium using and dietary pattern.

OBJECTIVES

The aim of the present study was to determine the daily intake of different nutrients in opium addict with diabetes diagnosed with coronary artery disease (CAD).

METHODS

This study comprised 232 consecutive diabetic patients with CAD, and candidates for isolated coronary artery bypass surgery in Tehran Heart Center. Of these, 26 patients were opium addicts. Nutritional assessment was obtained by a validated semi-quantitative food frequency questionnaire (FFQ).

RESULTS

In opium addicts compared to non-addicts, consumption of carbohydrates (360.0±120.9 versus 447.8±249.8 Gr/day, P=0.016) and vitamin A (1170.4±570.2 versus 1496.3±889.6 μg/d as Retinol Activity Equivalent (RAE), P=0.040) was lower than non-addicts and intake of other nutrients were similar across two group of patients.

CONCLUSIONS

Opium addiction in diabetic patients may lead to decrease of vitamin A and carbohydrate intake. This study showed that carbohydrate intake in addicted diabetic patients is lower than their non-addict counterpart. Thus, the so called lowering effect of opium on blood sugar may be due to nutritional habit of addicted patients.

Does co-morbid depression alter the inverse relationship between obesity and substance use disorders?

BACKGROUND

Substance use disorders and obesity are often inversely related to one another, hypothetically due to competition over shared neurobiological reward circuitry. However, obesity and substance use disorders share common risk factors, such as other psychiatric disorders. It is unknown whether the inverse relationship between obesity and substance use disorders continues to exist in the presence of shared risk factors.

METHODS

For the current study, we examined the associations between major depression, alcohol and drug use disorders, and overweight/obesity status in a nationally representative sample of U.S. adults (n=40,715).

RESULTS

Our findings demonstrated that adults with major depression were more likely to be obese, whereas adults with alcohol or drug use disorders were less likely to be obese. However, the inverse relationship between substance use and obesity continued to exist in adults with co-morbid depression. Adults with depression disorders co-morbid with alcohol (Relative Risk [RR]=0.63, 95% CI=0.47-0.84) or drug (RR=0.54, 95% CI=0.36-0.81) use disorders were less likely to be obese vs normal weight.

CONCLUSIONS

Our findings provide support for the proposal that excess food consumption and excess drug use appear to compete over shared neurobiology even when the motivation to self-medicate with either food or substances might be elevated.

Bilateral lesions of the thalamic trigeminal orosensory area dissociate natural from drug reward in contrast paradigms

Substance abuse and addiction are associated with an apparent devaluation of, and inattention to, natural rewards. This consequence of addiction can be modeled using a reward comparison paradigm where rats avoid intake of a palatable taste cue that comes to predict access to a drug of abuse. Evidence suggests rats avoid intake following such pairings, at least in part, because the taste cue pales in comparison to the highly rewarding drug expected in the near future. In accordance, lesions of the gustatory thalamus or cortex eliminate avoidance of a taste cue when paired with either a drug of abuse or a rewarding sucrose solution, but not when paired with the aversive agent, LiCl. The present study used bilateral ibotenic acid lesions to evaluate the role of a neighboring thalamic structure, the trigeminal orosensory area (TOA), in avoidance of a gustatory cue when paired with sucrose (experiment 1), morphine (experiment 2), cocaine (experiment 3), or LiCl (experiment 4). The results show that the TOA lesion disrupts, but does not eliminate avoidance of a taste cue that predicts access to a preferred sucrose solution and leaves intact the development of a LiCl-induced conditioned taste aversion. The lesion does, however, eliminate the suppression of intake of a taste cue when paired with experimenter-administered morphine or cocaine using our standard parameters. As such, this is the first manipulation found to dissociate avoidance of a taste cue when mediated by a sweet or by a drug of abuse.

Increased motivation to eat in opiate-withdrawn mice

RATIONALE

In drug-dependent individuals, the primary excessive motivation is for drugs. Studies also indicate altered interest for "natural" rewarding activities associated with motivational disorders that may be relevant to drug dependence. However, to date, the impact of drug dependence and withdrawal upon motivation for "natural" rewards remains unclear.

METHODS AND OBJECTIVES

In the present study, we use a food-driven operant behavior paradigm to assess the impact of opiate intake and withdrawal upon the motivational properties of highly palatable food (HPF) in mice.

RESULTS

Our findings indicate that early (8-h) opiate withdrawal does not affect either the motivational or the discriminative properties of HPF intake. However, starting 32 h after the last morphine injection, opiate withdrawal increases operant behavior aimed at obtaining HPF. The increased HPF-driven behavior lasts at least 12 days following opiate withdrawal, indicating long-lasting effects upon motivation. Using a paradigm of reward contingency reversal, we also address the impact of opiate withdrawal upon cognitive functions. Our results indicate that opiate withdrawal does not affect the ability to learn a new operant rule to obtain HPF. Indeed, opiate withdrawal ameliorates the acquisition of the new HPF-driven operant task, most probably due to the persistent and long-lasting increased motivation. Finally, analysis of ambulatory activity and body weight (BW) changes reveal that motivational and cognitive effects are totally independent of caloric and/or motor effects of opiate dosing and withdrawal.

CONCLUSIONS

These results clearly demonstrate that excessive opiate intake and withdrawal produces dramatic and long-lasting motivational disorders relevant to drug dependence.

Environmental enrichment protects against the acquisition of cocaine self-administration in adult male rats, but does not eliminate avoidance of a drug-associated saccharin cue

One of the most menacing consequences of drug addiction is the devaluation of natural rewards (e.g. food, sex, work, money, caring for one's offspring). However, evidence also suggests that natural rewards, such as an enriched environment, can devalue drugs of abuse. Thus, this study used a rodent model to test whether exposure to an enriched environment could protect adult rats from acquiring cocaine self-administration and from the resultant drug-induced devaluation of a natural saccharin reward cue. Adult male Sprague-Dawley rats were implanted with intravenous jugular catheters. Rats were then separated into two housing conditions: an enriched condition, including social companions(four/cage) and novel objects (e.g. balls, polyethylene tubes, paper, etc.), and a nonenriched condition where the rats were singly housed with no novel objects. During testing, the rats were given 5-min access to 0.15% saccharin, followed by 1 h to self-administer saline or cocaine (0.167 mg/infusion) on fixed ratio and progressive ratio schedules of reinforcement. The results showed that rats that were singly housed in the nonenriched environment fell into two groups: low drug-takers (n=34) and high drug-takers (n=12). In comparison, only one out of the 22 rats housed in the enriched environment was a high drug-taker. Thus, all rats in the enriched environment, except one, behaved like low drug-takers under the nonenriched condition. As such, these rats self-administered almost no drug on either the fixed ratio or the progressive ratio schedule of reinforcement and were extremely slow to self-administer their first cocaine infusion. Interestingly, despite their very low levels of drug self-administration, low-drug-taking rats housed in the enriched environment continued to avoid intake of the drug-associated saccharin cue. Taken together, these data suggest that the enriched environment itself served as a salient natural reward that reduced cocaine seeking and cocaine taking, but had little impact on avoidance of the cocaine-paired taste cue. The protective effects of the enriched environment were robust and, as such, have important implications for the methods used in the study of drug addiction in animal models and for the prevention, and possibly the treatment, of the disease in adult humans.