Altered HPA axis responsivity to metyrapone testing in methadone maintained former heroin addicts with ongoing cocaine addiction

Case report: The lesson from opioid withdrawal symptoms mimicking paraganglioma recurrence during opioid deprescribing in cancer pain

Pain is one of the predominant and troublesome symptoms that burden cancer patients during their whole disease trajectory: adequate pain management is a fundamental component of cancer care. Opioid are the cornerstone of cancer pain relief therapy and their skillful management must be owned by physicians approaching cancer pain patients. In light of the increased survival of cancer patients due to advances in therapy, deprescription should be considered as a part of the opioid prescribing regime, from therapy initiation, dose titration, and changing or adding drugs, to switching or ceasing. In clinical practice, opioid tapering after pain remission could be challenging due to withdrawal symptoms' onset. Animal models and observations in patients with opioid addiction suggested that somatic and motivational symptoms accompanying opioid withdrawal are secondary to the activation of stress-related process (mainly cortisol and catecholamines mediated). In this narrative review, we highlight how the lack of validated guidelines and tools for cancer patients can lead to a lower diagnostic awareness of opioid-related disorders, increasing the risk of developing withdrawal symptoms. We also described an experience-based approach to opioid withdrawal, starting from a case-report of a symptomatic patient with a history of metastatic pheochromocytoma-paraganglioma.

Evaluation of Serum Cortisol Levels and Response to Cosyntropin Test in Methadone-treated Opium Addicts

Background

Opium has been used for thousands of years for medical and analgesic purposes, and its misuse has also increased in recent years. Methadone, a synthetic opioid, has been used as an analgesic and to help patients quit opium addiction. However, some evidence suggests that long-term use of opioids can affect the hypothalamic-pituitary-adrenal axis.

Objectives

We aimed to evaluate the serum cortisol level and response to the cosyntropin stimulation test in opium addicts on methadone treatment.

Methods

The study was conducted in November 2019 at Imam Reza Hospital Rehab Center, Birjand, Iran. Thirty-eight methadone-treated opium addicts participated in the study. A blood sample was initially obtained, then 250 µg intramuscular cosyntropin was injected. After 30 and 60 minutes, two other blood samples were obtained. The data were analyzed using SPSS.

Results

There was a significant difference between serum cortisol levels and the normal value in methadone users (9.46 ± 5.42 vs. 14 µg/dL) (P < 0.001). The mean response to the cosyntropin stimulation test in methadone users was 9.34 ± 8.11 µg/dL. Also, 55% of the participants had adrenal insufficiency.

Conclusions

Serum cortisol levels significantly differed from normal values in methadone-treated patients. Therefore, we recommend measuring serum cortisol levels in methadone-treated patients before major medical procedures to consider the stress doses of corticosteroids.

Risk factors for opioid use disorder after severe burns in adults

INTRODUCTION

Risk factors for opioid dependence amongst burn patients have not been well-explored compared to other surgical fields.

METHODS

The TrinetX database was queried for patients diagnosed with opioid use disorder (OUD) after thermal or chemical burn. Propensity score matching was performed. Opioid and non-opioid analgesia use, ICU care, surgery, and comparative risks among common opiates were examined using descriptive and univariate regression models, including odds ratios. Subgroup analysis evaluated the impact of multimodal analgesia.

RESULTS

Odds of receiving IV opioids for acute analgesia (p = <0.0001, OR = 1.80, CI = 1.45-2.25), undergoing surgery (p = <0.0001, OR = 1.58, CI = 1.26-1.98), and ICU care (p = <0.0001, OR = 3.60, CI = 2.00-3.83) after burn injury were higher in patients who developed OUD. Patients receiving multimodal therapy within 24 hours of admission had lower odds of developing OUD (OR = 0.74, CI = 2.76-4.68, p = 0.0001) and chronic pain (OR = 0.89, CI = 0.78-1.00, p = 0.05) regardless of TBSA.

CONCLUSION

Patients who developed opioid use disorder following burn injury had higher odds of receiving opioid exclusive pain management, more frequent surgery, ICU care.

Intranasal oxytocin may improve odds of abstinence in cocaine-dependent patients: results from a preliminary study

Background

Oxytocin (OT) treatment in drug addiction studies have suggested potential therapeutic benefits. There is a paucity of clinical trial studies of oxytocin in cocaine use disorders.

Method

This was a 6-week randomized, double-blind, outpatient clinical trial study investigating the effect of daily Intranasal Oxytocin (24 IU) on cocaine use by cocaine use disorder patients. After a 7-day inpatient abstinence induction stage, patients were randomized to intranasal oxytocin or intranasal placebo. During the outpatient phase, cocaine use disorder patients were required to present themselves to the research staff 3 times a week for witnessed randomized medication administration, to provide a urine sample for qualitative toxicology, and complete mandatory assessments, including the Time-Line-Follow Back. For the interim days, patients were given an "at-home" bottle that was weighed at each clinic visit to monitor compliance.

Results

Neither administration of Intranasal placebo (n = 11) or Oxytocin (n = 15) induced at least 3 weeks of continuous abstinence. However, from week 3, the odds of weekly abstinence increased from 4.61 (95% CI = 1.05, 20.3) to 15.0 (CI = 1.18, 190.2) by week 6 for the Intranasal Oxytocin group (t = 2.12, p = 0.037), though there was no significant group difference overall in the odds of abstinence over time (F_1,69 = 1.73, p = 0.19). More patients on Intranasal Oxytocin dropped out (p = 0.0005).

Conclusions

Intranasal Oxytocin increased the odds of weekly abstinence in Cocaine patients after 2 weeks compared to PBO, but was associated with a higher dropout rate. (ClinicalTrials.gov 02,255,357, 10/2014).

Electro-Acupuncture Combined Methadone for Withdrawal Symptoms of Opioid Addiction: A Protocol for Systematic Review and Meta-Analysis

Background<br/> Opioid addiction is a chronic brain disorder characterized by a series of withdrawal symptoms in behavioral, psychological, and neurobiological manifestations. Withdrawal symptoms are the main cause of relapse after periods of abstinence; thus, the treatment is focused on abstinence symptoms. Due to most of all types of opioid agonist drugs carry a potential for addiction and exacerbation of withdrawal symptoms, nondrug methods have great potentials in clinical applications. Electro-acupuncture (EA), as a novel nonpharmacological approach, combined with methadone has a long-term positive efficacy on treating addiction. Therefore, we designed a protocol to evaluate the adjuvant effect of EA for treating withdrawal symptoms of opioid addiction.<br/> Method<br/> To review reports of relevant clinical trials, we will search English language databases (EMBASE, PubMed, and the Cochrane Central Register of Controlled Trials) and Chinese databases (Chinese Biomedical Literatures, China National Knowledge Infrastructure, Wanfang, and VIP). We will collect documents from the earliest possible date up to May 2020. We will also search online trial registries such as ClinicalTrials. gov (ClinicalTrials.gov/), the European Medicine Agency (www.ema.europa.eu/ema/), and WHO International Clinical Trials Registry Platform (www.who.int/ictrp). We will select randomized controlled trials (RCT) for withdrawal from opioid addiction involving EA-methadone and methadone alone treatment. We will use psychological assessment scales to evaluate treatment major outcomes which include numerous components such as OWS, VAS, HAMD, HAMA; then urinalysis and methadone dosage also will be measure as the additional outcomes. Finally, RevMan5 software will be used for literature quality evaluation and data analysis.<br/> Result:<br/> To evaluate the efficacy of EA in combination therapy by observing the outcomes of corresponding scale, urinalysis and decreasing methadone.<br/> Conclusion:<br/> This protocol will be used to evaluate the efficacy and safety of EA in combination with methadone in treatment of opioid addiction withdrawal symptoms.<br/> Abbreviations: Opioid dependence, OWS=Opiate Withdrawal Scale, VAS=Craving Visual Analog Scale, PWSS=Post-withdrawal symptoms Scale, HAMD=Hamilton Depression Scale, HAMA=Hamilton Anxiety Scale, RCTs=Randomized Controlled Trials, EA=Electrical Acupuncture, PRISMA=Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Can the migration process influence the clinical expression of heroin use disorder in migrants to Italy?

BACKGROUND

For some time now, there has been a strong consensus that the migration process can influence the onset, course, development, outcome, and clinical aspects of psychiatric pathologies.

METHODS

In this study, we have analyzed the influence of the migration process on the clinical expression of heroin use disorder (HUD). In a naturalistic case-control study, we compared, both at univariate and multivariate level, 30 migrant HUD (M-HUD) patients with 30 age/gender-matched Italian HUD (IT-HUD) patients. We also analyzed demographic data, drug addiction history, psychopathological symptoms, addictive behavior, and emotional reactivity to life events.

RESULTS

Compared with IT-HUD pairs, at HUD Agonist Opioid Treatment, M-HUD patients were characterized by inadequate income and the presence of legal problems. They were more frequently at stage 3 of heroin addiction, with a concomitantly less frequent use of stimulants. Their age at the onset of heroin use was greater than that of subjects in the IT-HUD group. HUD post-traumatic stress disorder spectrum was present and was more severe in all M-HUD patients, but grief reactions and maladaptive behavior were the most discriminant traits. No differences were found in terms of addictive behaviors related to heroin craving or with respect to the severity/typology of psychopathology specific to HUD.

CONCLUSIONS

The migratory process does not seem to be correlated with addictive behaviors or with psychopathology specific to HUD. It partly affects HUD history, and specifically correlates with emotional reactivity to loss and traumatic life events, so suggesting that in M-HUD individuals, the link between the migratory syndrome and HUD is very close.

Stress indices in methadone maintenance treatment - Cross sectional and follow up study

To study the prevalence of perceived high stress among methadone maintenance treatment (MMT) patients, and whether stress can predict outcome, and whether stress may improve during treatment, we studied a sample of 107 MMT patients using Perceived Stress Scale (PSS) questionnaires. We studied if PSS scores on admission predict long-term retention, and we monitored stress indices (PSS, heart rate variability, saliva cortisol) on admission, 6 and 12 months later, to measure changes. Variables included demographic data, history of adverse events, and urine test. A sample of 79 (73.8%) males and 28 (26.2%) females whose age at opioid use onset was 22.1±7.2 years and age at study onset 50.5±10.8 years was studied for PSS. Both high and very-high PSS patients characterized (logistic regression) as abusing benzodiazepine, and with history of depressive symptoms. The very-high PSS group on admission (n=29) had shorter cumulative retention (1.8 years, 95%%CI 1.2-2.4) compared with 50 others (2.8 years, 95%%CI 2.3-3.3, p=0.03). Monitoring stress indices among 25 patients found that no-benzodiazepine and cocaine use on admission, opioid discontinuation after 6 months, and any substance discontinuation after a year were associated with stress reduction. Conclusion: stress level appears to normalize among MMT patients if no other substance is abused.

Current status of opioid addiction treatment and related preclinical research

Opioid use disorders (OUDs) are diseases of the brain with behavioral, psychological, neurobiological, and medical manifestations. Vulnerability to OUDs can be affected by factors such as genetic background, environment, stress, and prolonged exposure to μ-opioid agonists for analgesia. Two standard-of-care maintenance medications, methadone and buprenorphine-naloxone, have a long-term positive influence on health of persons with opioid addiction. Buprenorphine and another medication, naltrexone, have also been approved for administration as monthly depot injections. However, neither medication is used as widely as needed, due largely to stigma, insufficient medical education or training, inadequate resources, and inadequate access to treatment. Ongoing directions in the field include (i) personalized approaches leveraging genetic factors for prediction of OUD vulnerability and prognosis, or for targeted pharmacotherapy, and (ii) development of novel analgesic medicines with new neurobiological targets with reduced abuse potential, reduced toxicity, and improved effectiveness, especially for chronic pain states other than cancer pain.

Interaction Between Stress and Addiction: Contributions From Latin-American Neuroscience

Drug addiction is a chronic neuropsychiatric disorder that escalates from an initial exposure to drugs of abuse, such as cocaine, cannabis, or heroin, to compulsive drug-seeking and intake, reduced ability to inhibit craving-induced behaviors, and repeated cycles of abstinence and relapse. It is well-known that chronic changes in the brain’s reward system play an important role in the neurobiology of addiction. Notably, environmental factors such as acute or chronic stress affect this system, and increase the risk for drug consumption and relapse. Indeed, the HPA axis, the autonomic nervous system, and the extended amygdala, among other brain stress systems, interact with the brain’s reward circuit involved in addictive behaviors. There has been a growing interest in studying the molecular, cellular, and behavioral mechanisms of stress and addiction in Latin-America over the last decade. Nonetheless, these contributions may not be as strongly acknowledged by the broad scientific audience as studies coming from developed countries. In this review, we compile for the first time a series of studies conducted by Latin American-based neuroscientists, who have devoted their careers to studying the interaction between stress and addiction, from a neurobiological and clinical perspective. Specific contributions about this interaction include the study of CRF receptors in the lateral septum, investigations on the neural mechanisms of cross-sensitization for psychostimulants and ethanol, the identification of the Wnt/β-catenin pathway as a critical neural substrate for stress and addiction, and the emergence of the cannabinoid system as a promising therapeutic target. We highlight animal and human studies, including for instance, reports coming from Latin American laboratories on single nucleotide polymorphisms in stress-related genes and potential biomarkers of vulnerability to addiction, that aim to bridge the knowledge from basic science to clinical research.

Anti-stress neuropharmacological mechanisms and targets for addiction treatment: A translational framework

Stress-related substance use is a major challenge for treating substance use disorders. This selective review focuses on emerging pharmacotherapies with potential for reducing stress-potentiated seeking and consumption of nicotine, alcohol, marijuana, cocaine, and opioids (i.e., key phenotypes for the most commonly abused substances). I evaluate neuropharmacological mechanisms in experimental models of drug-maintenance and relapse, which translate more readily to individuals presenting for treatment (who have initiated and progressed). An affective/motivational systems model (three dimensions: valence, arousal, control) is mapped onto a systems biology of addiction approach for addressing this problem. Based on quality of evidence to date, promising first-tier neurochemical receptor targets include: noradrenergic (α1 and β antagonist, α2 agonist), kappa-opioid antagonist, nociceptin antagonist, orexin-1 antagonist, and endocannabinoid modulation (e.g., cannabidiol, FAAH inhibition); second-tier candidates may include corticotropin releasing factor-1 antagonists, serotonergic agents (e.g., 5-HT reuptake inhibitors, 5-HT3 antagonists), glutamatergic agents (e.g., mGluR2/3 agonist/positive allosteric modulator, mGluR5 antagonist/negative allosteric modulator), GABA-promoters (e.g., pregabalin, tiagabine), vasopressin 1b antagonist, NK-1 antagonist, and PPAR-γ agonist (e.g., pioglitazone). To address affective/motivational mechanisms of stress-related substance use, it may be advisable to combine agents with actions at complementary targets for greater efficacy but systematic studies are lacking except for interactions with the noradrenergic system. I note clinically-relevant factors that could mediate/moderate the efficacy of anti-stress therapeutics and identify research gaps that should be pursued. Finally, progress in developing anti-stress medications will depend on use of reliable CNS biomarkers to validate exposure-response relationships.

Elevated Hair Cortisol Levels among Heroin Addicts on Current Methadone Maintenance Compared to Controls

Whether methadone maintenance treatment (MMT) can improve the basal function of the hypothalamic–pituitary–adrenal (HPA) axis, which is suppressed by long-term heroin consumption, is a matter of debate. The stress state and depression and anxiety symptoms may affect the basal activity of the HPA axis in MMT patients. However, the effect of psychological factors on HPA activity was not simultaneously controlled in previous studies. This study investigated differences in HPA basal activity between MMT patients and controls using psychological variables as covariates. The participants included 52 MMT patients and 41 age-matched, non-heroin-dependent controls. Psychological states were self-reported with the Perceived Stress Scale, Self-Rating Depression Scale and Self-Rating Anxiety Scale. The hair cortisol level was adopted as a biomarker of HPA basal activity and was determined with liquid chromatography tandem mass spectrometry. The results revealed that MMT patients had significantly higher hair cortisol levels than the controls (p<0.05), but the difference was not significant (p>0.05) when the perceived stress, depression and anxiety scores were used as covariates. We concluded that patients with long-term MMT showed higher basal activity of the HPA axis. The high chronic stress state and increase in depression and anxiety symptoms may mask the suppression effect of methadone on the HPA activity.

Psychological and physiological stress negatively impacts early engagement and retention of opioid-dependent individuals on methadone maintenance

The present study investigated whether psychological and/or physiological measures of stress would impede induction onto methadone maintenance and predict early (<6 months) discontinuation. Compared with controls, opioid-dependent subjects displayed increased distress on the perceived stress scale (PSS) and post-traumatic stress disorder checklist (PCLC); 60% exhibited abnormal cortisol. Addiction severity index (ASI), drug-use, and stress indices explained between 17 and 37% of the variance in engagement including attendance, opioid abstinence, and methadone stabilization. Participants who discontinued treatment displayed poor engagement, abnormal cortisol, elevated withdrawal symptoms, higher distress, and increased ongoing opioid use versus compliant individuals. Discontinuation was initially related to drug-use severity; however, by 6 months, retention depended primarily upon cortisol abnormalities, which increased an individual's discontinuation risk by 7.7-fold. These findings support admission screening with the ASI/cortisol for drop out, and stress/drug-use indices for engagement that together may enable clinically-relevant early recognition and interventions for prevention of stress-induced relapse in opioid-dependent populations.

Alcohol: a stimulant activating brain stress responsive systems with persistent neuroadaptation

Addictive diseases, including addiction to alcohol, opiates or cocaine, pose massive public health costs. Addictions are chronic relapsing brain diseases, caused by drug-induced direct effects and persistent neuroadaptations at the molecular, cellular and behavioral levels. These drug-type specific neuroadapations are mainly contributed by three factors: environment, including stress, the direct reinforcing effects of the drug on the CNS, and genetics. Results from animal models and basic clinical research (including human genetic study) have shown important interactions between the stress responsive systems and alcohol abuse. In this review we will discuss the involvement of the dysregulation of the stress responsive hypothalamic-pituitary-adrenal (HPA) axis in alcohol addiction (Section I). Addictions to specific drugs such as alcohol, psychostimulants and opiates (e.g., heroin) have some common direct or downstream effects on several brain stress-responsive systems, including vasopressin and its receptor system (Section II), POMC and mu opioid receptor system (Section III) and dynorphin and kappa opioid receptor systems (Section IV). Further understanding of these systems, through laboratory-based and translational studies, have the potential to optimize early interventions and to discover new treatment targets for the therapy of alcoholism. This article is part of the Special Issue entitled 'CNS Stimulants'.

Adolescents' use of alcohol, tobacco and illicit drugs in relation to prenatal alcohol exposure: modifications by gender and ethnicity

AIMS

The study aimed to investigate (a) the association between low to moderate prenatal alcohol exposure (PAE) and the use of alcohol, tobacco and illicit drugs in adolescence and (b) whether the associations are modified by gender and ethnicity.

METHODS

The subjects of the study were 5922 children and adolescents, aged from 11 to 17 years, enrolled in the cross-sectional German Health Interview and Examination Survey for Children and Adolescents (the KiGGS study). Information on PAE is based on parental self-report questionnaires. Use of alcohol, tobacco and illicit drugs was assessed through self-report questionnaires for adolescents.

RESULTS

Low to moderate PAE was associated with an increased risk of drinking alcohol (adjusted odds ratio (OR) 1.73, 95% confidence interval (CI) 1.34, 2.18) and also of illicit drug use (adjusted OR 1.62, 95% CI 1.23, 2.14). The associations between PAE and the use of alcohol, tobacco and illicit drugs differed according to gender and ethnicity. Gender-stratified analyses resulted in adverse effects of PAE on drinking alcohol, smoking and illicit drug use in females; however, in German males, the associations disappeared. Stronger associations between PAE and the outcome measures were found in non-Germans.

CONCLUSIONS

Our findings indicate that low to moderate levels of maternal alcohol intake during pregnancy are a risk factor for use of alcohol, tobacco and illicit drugs by the offspring, with stronger associations in females and non-Germans.

Suppression of hypothalamic-pituitary-adrenal axis by acute heroin challenge in rats during acute and chronic withdrawal from chronic heroin administration

It is known that heroin dependence and withdrawal are associated with changes in the hypothalamic-pituitary-adrenal (HPA) axis. The objective of these studies in rats was to systematically investigate the level of HPA activity and response to a heroin challenge at two time points during heroin withdrawal, and to characterize the expression of associated stress-related genes 30 min after each heroin challenge. Rats received chronic (10-day) intermittent escalating-dose heroin administration (3 × 2.5 mg/kg/day on day 1; 3 × 20 mg/kg/day by day 10). Hormonal and neurochemical assessments were performed in acute (12 h after last heroin injection) and chronic (10 days after the last injection) withdrawal. Both plasma ACTH and corticosterone levels were elevated during acute withdrawal, and heroin challenge at 20 mg/kg (the last dose of chronic escalation) at this time point attenuated this HPA hyperactivity. During chronic withdrawal, HPA hormonal levels returned to baseline, but heroin challenge at 5 mg/kg decreased ACTH levels. In contrast, this dose of heroin challenge stimulated the HPA axis in heroin naïve rats. In the anterior pituitary, pro-opiomelanocortin (POMC) mRNA levels were increased during acute withdrawal and retuned to control levels after chronic withdrawal. In the medial hypothalamus, however, the POMC mRNA levels were decreased during acute withdrawal, and increased after chronic withdrawal. Our results suggest a long-lasting change in HPA abnormal responsivity during chronic heroin withdrawal.

Animal studies trigger new insights on the use of methadone maintenance

BACKGROUND

Although steady-state methadone (SSM) treatment is mainly used for opioid addiction, some clinical studies indicate that it also reduces cocaine abuse in opioid-dependent individuals.

OBJECTIVE/METHODS

To present evidence suggesting that SSM may be useful in the treatment of cocaine addiction without pre-existing opioid dependence. We review studies in animals investigating the effects of SSM on behaviors motivated by cocaine and on cocaine-induced alterations of genes expression in the rat brain.

CONCLUSION

SSM reduces cocaine intake, blocks cocaine seeking and normalizes expression of genes known to regulate cocaine seeking. These findings suggest that SSM could be an effective pharmacological agent to assist cocaine detoxification and prevention of relapse to cocaine abuse in individuals not co-dependent on opioid.

Mu-opioid receptor A118G polymorphism in healthy volunteers affects hypothalamic-pituitary-adrenal axis adrenocorticotropic hormone stress response to metyrapone

The mu-opioid receptor encoded by the gene OPRM1 plays a primary role in opiate, alcohol, cocaine and nicotine addiction. Studies using opioid antagonists demonstrate that the mu-opioid receptor (MOP-r) also mediates the hypothalamic-pituitary-adrenal (HPA) axis stress response. A common polymorphism in exon one of the MOP-r gene, A118G, has been shown to significantly alter receptor function and MOP-r gene expression; therefore, this variant likely affects HPA-axis responsivity. In the current study, we have investigated whether the presence of the 118AG variant genotype affects HPA axis responsivity to the stressor metyrapone, which transiently blocks glucocorticoid production in the adrenal cortex. Forty-eight normal and healthy volunteers (32 men, 16 women) were studied, among whom nine men and seven women had the 118AG genotype. The 118G allele blunted the adrenocorticotropic hormone (ACTH) response to metyrapone. Although there was no difference in basal levels of ACTH, subjects with the 118AG genotype had a more modest rise and resultant significantly lower ACTH levels than those with the prototype 118AA at the 8-hour time point (P < 0.02). We found no significant difference between genders. These findings suggest a relatively greater tonic inhibition at hypothalamic-pituitary sites through the mu-opioid receptor and relatively less cyclical glucocorticoid inhibition in subjects with the 118G allele.

The endogenous opioid system in cocaine addiction: what lessons have opioid peptide and receptor knockout mice taught us?

Cocaine addiction has become a major concern in the UK as Britain tops the European 'league table' for cocaine abuse. Despite its devastating health and socio-economic consequences, no effective pharmacotherapy for treating cocaine addiction is available. Identifying neurochemical changes induced by repeated drug exposure is critical not only for understanding the transition from recreational drug use towards compulsive drug abuse but also for the development of novel targets for the treatment of the disease and especially for relapse prevention. This article focuses on the effects of chronic cocaine exposure and withdrawal on each of the endogenous opioid peptides and receptors in rodent models. In addition, we review the studies that utilized opioid peptide or receptor knockout mice in order to identify and/or clarify the role of different components of the opioid system in cocaine-addictive behaviours and in cocaine-induced alterations of brain neurochemistry. The review of these studies indicates a region-specific activation of the µ-opioid receptor system following chronic cocaine exposure, which may contribute towards the rewarding effect of the drug and possibly towards cocaine craving during withdrawal followed by relapse. Cocaine also causes a region-specific activation of the κ-opioid receptor/dynorphin system, which may antagonize the rewarding effect of the drug, and at the same time, contribute to the stress-inducing properties of the drug and the triggering of relapse. These conclusions have important implications for the development of effective pharmacotherapy for the treatment of cocaine addiction and the prevention of relapse.

Opiate addiction and cocaine addiction: underlying molecular neurobiology and genetics

Addictive diseases, including addiction to heroin, prescription opioids, or cocaine, pose massive personal and public health costs. Addictions are chronic relapsing diseases of the brain caused by drug-induced direct effects and persisting neuroadaptations at the epigenetic, mRNA, neuropeptide, neurotransmitter, or protein levels. These neuroadaptations, which can be specific to drug type, and their resultant behaviors are modified by various internal and external environmental factors, including stress responsivity, addict mindset, and social setting. Specific gene variants, including variants encoding pharmacological target proteins or genes mediating neuroadaptations, also modify vulnerability at particular stages of addiction. Greater understanding of these interacting factors through laboratory-based and translational studies have the potential to optimize early interventions for the therapy of chronic addictive diseases and to reduce the burden of relapse. Here, we review the molecular neurobiology and genetics of opiate addiction, including heroin and prescription opioids, and cocaine addiction.

Maintenance medication for opiate addiction: the foundation of recovery

Illicit use of opiates is the fastest growing substance use problem in the United States, and the main reason for seeking addiction treatment services for illicit drug use throughout the world. It is associated with significant morbidity and mortality related to human immunodeficiency virus, hepatitis C, and overdose. Treatment for opiate addiction requires long-term management. Behavioral interventions alone have extremely poor outcomes, with more than 80% of patients returning to drug use. Similarly poor results are seen with medication-assisted detoxification. This article provides a topical review of the three medications approved by the Food and Drug Administration for long-term treatment of opiate dependence: the opioid-agonist methadone, the partial opioid-agonist buprenorphine, and the opioid-antagonist naltrexone. Basic mechanisms of action and treatment outcomes are described for each medication. Results indicate that maintenance medication provides the best opportunity for patients to achieve recovery from opiate addiction. Extensive literature and systematic reviews show that maintenance treatment with either methadone or buprenorphine is associated with retention in treatment, reduction in illicit opiate use, decreased craving, and improved social function. Oral naltrexone is ineffective in treating opiate addiction, but recent studies using extended-release naltrexone injections have shown promise. Although no direct comparisons between extended-release naltrexone injections and either methadone or buprenorphine exist, indirect comparison of retention shows inferior outcome compared with methadone and buprenorphine. Further work is needed to directly compare each medication and determine individual factors that can assist in medication selection. Until such time, selection of medication should be based on informed choice following a discussion of outcomes, risks, and benefits of each medication.

Cue-induced reactivity, cortisol response and substance use outcome in treated heroin dependent individuals

BACKGROUND

Environmental stimuli associated with drug taking have been known to elicit drug craving and physiologic arousal, as well as hypothalamic-pituitary-adrenal axis activation. However, the relationship between these responses and substance use outcomes in heroin-dependent subjects has not been previously studied. We investigated the relationship among subjective and physiologic reactivity, biological stress response evoked in the laboratory, and relapse to substance use in treated opiate-dependent individuals.

METHODS

Eighteen opiate-abstinent methadone- or buprenorphine-treated patients and 13 control subjects were exposed to neutral- and drug-cue exposure laboratory sessions with a 3-month follow-up period. Exposure to cues involved both videotapes and handling during a 100-min session. Subjective craving, agonistic effects, withdrawal feelings, galvanic skin resistance, and salivary cortisol were assessed. Substance use outcome among patients was examined during the follow-up phase. Differences between relapsers, nonrelapsers, and controls were analyzed with respect to the data on drug-cue responsivity and on cortisol responses using repeated-measures analysis of variance. The association with substance use outcome was assessed using a nominal logistic model.

RESULTS

Relapsers experienced greater drug-cue induced subjective responses and an increased cortisol response compared with both nonrelapsers and control subjects. After adjusting on covariates, cue-induced cortisol response was associated with the relapser group and was highly correlated with self-reports of "high."

CONCLUSIONS

Subjects defined as relapsers presented a higher cue-induced reactivity during the drug-cue exposure as well as an increased cortisol response to drug cues. Higher cortisol response to drug cues may increase relapse vulnerability in stable-dose buprenorphine or methadone-maintained subjects.

Persistent increase in hypothalamic arginine vasopressin gene expression during protracted withdrawal from chronic escalating-dose cocaine in rodents

Arginine vasopressin (AVP) from the paraventricular nucleus (PVN) of hypothalamus has important roles in regulation of the hypothalamic-pituitary-adrenal (HPA) axis and stress-related behaviors during chronic stress. It is unknown, however, whether AVP in the PVN is involved in the modulation of HPA activity after chronic cocaine exposure. Here, we examined the gene expression alterations of AVP in the hypothalamus, and V1b receptor and pro-opiomelanocortin (POMC) in the anterior pituitary, as well as HPA hormonal changes, in Fischer rats after chronic cocaine and withdrawal, using two different chronic (14-day) 'binge' pattern administration regimens: steady-dose cocaine (SDC, 45 mg/kg/day) and escalating-dose cocaine (EDC, 45 up to 90 mg/kg/day). There was a significant (7-fold) plasma adrenocorticotropic hormone (ACTH) elevation after chronic EDC (but not SDC), coupled with increased V1b and POMC mRNA levels in the anterior pituitary. From acute (1-day) to protracted (14-day) withdrawal from chronic EDC (but not from SDC), we found persistent elevations of both plasma ACTH and corticosterone levels and AVP mRNA levels in the PVN. Selective V1b antagonist SSR149415 (5 mg/kg) attenuated acute withdrawal-induced HPA activation after EDC. To study potential roles of endogenous opioids in modulating the AVP gene, we administered naloxone (1 mg/kg); we found that opioid receptor antagonism increased AVP mRNA levels in cocaine-naive rats, but not in cocaine-withdrawn rats, suggesting less tonic opioid inhibition of PVN AVP neurons after chronic EDC. To assess the effects of cocaine withdrawal on sub-populations of PVN AVP neurons, we utilized AVP-enhanced green fluorescent protein (EGFP) promoter transgenic mice and found that acute withdrawal following chronic EDC increased the number of AVP-EGFP neurons in the parvocellular PVN (pPVN). These results suggest that during protracted withdrawal, enhanced pPVN AVP gene expression is associated with persistent elevations of basal HPA activity; a hyposensitivity of PVN AVP gene expression to naloxone is indicative of reduced opioidergic tone. Our studies indicate that the AVP and its V1b receptor system may be a potential therapeutic target for treating anxiety and depressive symptoms associated with cocaine addiction.

Heroin reduces startle and cortisol response in opioid-maintained heroin-dependent patients

Heroin dependence (HD) is a chronic relapsing brain disorder characterized by a compulsion to seek and use heroin. Stress is seen as a key factor for heroin use. Methadone maintenance and the prescription of pharmaceutical heroin [diacetylmorphine (DAM)] are established treatments for HD in several countries. The present study examined whether DAM-maintained patients and methadone-maintained patients differ from healthy controls in startle reflex and cortisol levels. Fifty-seven participants, 19 of each group matched for age, sex and smoking status, completed a startle session which included the presentation of 24 bursts of white noise while eye-blink responses to startling noises were recorded. Salivary cortisol was collected three times after awakening, before, during and after the startle session. DAM was administered before the experiment, while methadone was administered afterwards. Both heroin-dependent patient groups exhibited significantly smaller startle responses than healthy controls (P < 0.05). Whereas the cortisol levels after awakening did not differ across the three groups, the experimental cortisol levels were significantly lower in DAM-maintained patients, who received their opioid before the experiment, than in methadone-maintained patients and healthy controls (P < 0.0001). Opioid maintenance treatment for HD is associated with reduced startle responses. Acute DAM administration may suppress cortisol levels, and DAM maintenance treatment may represent an effective alternative to methadone in stress-sensitive, heroin-dependent patients.

Identification of substance use and dependence among patients with viral hepatitis

BACKGROUND

As drug abuse and addiction have been shown to decrease adherence to treatment of hepatitis C virus (HCV) or HIV, screening for substance use should be standard clinical practice in those undergoing an evaluation for these diseases.

AIMS

To assess the effectiveness of the Kreek-McHugh-Schluger-Kellogg (KMSK) scale to quantify substance use and dependence among patients with viral hepatitis.

METHODS

The KMSK scale, a validated instrument that quantifies lifetime use of alcohol, cocaine, heroin, and tobacco, was distributed to 161 consecutive patients referred to a hepatology clinic at an academic, tertiary-care center over a 1-year period.

RESULTS

Of the 159 patients who returned the KMSK scale, 62% reported illicit drug use and 30% met defined criteria for lifetime dependence on cocaine or heroin. We found that 15% of our population at some time had been co-dependent on cocaine and heroin. The KMSK scale identified significantly more cocaine, heroin, and alcohol use than that detected through the medical record (chi(2)=7.61, p<0.01, chi(2)=9.66, p<0.002, respectively). Cocaine dependence was significantly higher among HCV/HIV co-infected than among mono-infected patients (chi(2)=5.46, p<0.02).

CONCLUSIONS

The KMSK scale may be useful to diagnose drug and alcohol use and dependence among patients undergoing evaluation for treatment of viral hepatitis.

Search for genetic markers and functional variants involved in the development of opiate and cocaine addiction and treatment

Addiction to opiates and illicit use of psychostimulants is a chronic, relapsing brain disease that, if left untreated, can cause major medical, social, and economic problems. This article reviews recent progress in studies of association of gene variants with vulnerability to develop opiate and cocaine addictions, focusing primarily on genes of the opioid and monoaminergic systems. In addition, we provide the first evidence of a cis-acting polymorphism and a functional haplotype in the PDYN gene, of significantly higher DNA methylation rate of the OPRM1 gene in the lymphocytes of heroin addicts, and significant differences in genotype frequencies of three single-nucleotide polymorphisms of the P-glycoprotein gene (ABCB1) between "higher" and "lower" methadone doses in methadone-maintained patients. In genomewide and multigene association studies, we found association of several new genes and new variants of known genes with heroin addiction. Finally, we describe the development and application of a novel technique: molecular haplotyping for studies in genetics of drug addiction.

Drug-induced and genetic alterations in stress-responsive systems: Implications for specific addictive diseases

From the earliest work in our laboratory, we hypothesized, and with studies conducted in both clinical research and animal models, we have shown that drugs of abuse, administered or self-administered, on a chronic basis, profoundly alter stress-responsive systems. Alterations of expression of specific genes involved in stress responsivity, with increases or decreases in mRNA levels, receptor, and neuropeptide levels, and resultant changes in hormone levels, have been documented to occur after chronic intermittent exposure to heroin, morphine, other opiates, cocaine, other stimulants, and alcohol in animal models and in human molecular genetics. The best studied of the stress-responsive systems in humans and mammalian species in general is undoubtedly the HPA axis. In addition, there are stress-responsive systems in other parts in the brain itself, and some of these include components of the HPA axis, such as CRF and CRF receptors, along with POMC gene and gene products. Several other stress-responsive systems are known to influence the HPA axis, such as the vasopressin-vasopressin receptor system. Orexin-hypocretin, acting at its receptors, may effect changes which suggest that it should be properly categorized as a stress-responsive system. However, less is known about the interactions and connectivity of some of these different neuropeptide and receptor systems, and in particular, about the possible connectivity of fast-acting (e.g., glutamate and GABA) and slow-acting (including dopamine, serotonin, and norepinephrine) neurotransmitters with each of these stress-responsive components and the resultant impact, especially in the setting of chronic exposure to drugs of abuse. Several of these stress-responsive systems and components, primarily based on our laboratory-based and human molecular genetics research of addictive diseases, will be briefly discussed in this review.

Steady-state methadone effect on generalized arousal in male and female mice

Methadone is widely used in treatment of short-acting opiate addiction. The on-off effects of opioids have been documented to have profound differences from steady-state opioids. The authors hypothesize that opioids play important roles in either generalized arousal (GA) or aversive state of arousal during opioid withdrawal. Both male and female C57BL6 mice received steady-state methadone (SSM) through osmotic pumps at 10 or 20 mg/kg/day, and GA was measured in voluntary motor activity, sensory responsivity, and contextual fear conditioning. SSM did not have any effect on those GA behaviors in either sex. Females had higher activity and less fear conditioning than males. The effects of SSM on stress-responsive orexin gene expression in the lateral hypothalamus (LH) and medial hypothalamus (MH, including perifornical and dorsomedial areas) were measured after the behavioral tests. Females showed significantly lower basal LH (but not MH) orexin mRNA levels than males. A panel of GA stressors increased LH orexin mRNA levels in females only; these increases were blunted by SSM at 20 mg/kg. In summary, SSM had no effect on GA behaviors. In females, SSM blunted the GA stress-induced LH orexin gene expression.

Chronic stress, drug use, and vulnerability to addiction

Stress is a well-known risk factor in the development of addiction and in addiction relapse vulnerability. A series of population-based and epidemiological studies have identified specific stressors and individual-level variables that are predictive of substance use and abuse. Preclinical research also shows that stress exposure enhances drug self-administration and reinstates drug seeking in drug-experienced animals. The deleterious effects of early life stress, child maltreatment, and accumulated adversity on alterations in the corticotropin releasing factor and hypothalamic-pituitary-adrenal axis (CRF/HPA), the extrahypothalamic CRF, the autonomic arousal, and the central noradrenergic systems are also presented. The effects of these alterations on the corticostriatal-limbic motivational, learning, and adaptation systems that include mesolimbic dopamine, glutamate, and gamma-amino-butyric acid (GABA) pathways are discussed as the underlying pathophysiology associated with stress-related risk of addiction. The effects of regular and chronic drug use on alterations in these stress and motivational systems are also reviewed, with specific attention to the impact of these adaptations on stress regulation, impulse control, and perpetuation of compulsive drug seeking and relapse susceptibility. Finally, research gaps in furthering our understanding of the association between stress and addiction are presented, with the hope that addressing these unanswered questions will significantly influence new prevention and treatment strategies to address vulnerability to addiction.

Endocrine and gene expression changes following forced swim stress exposure during cocaine abstinence in mice

RATIONALE

Stress can reinstate previous cocaine-seeking long after drug is no longer present. However, little is known regarding the effect of chronic drug exposure and subsequent drug abstinence on responsivity to stress.

OBJECTIVE

To determine the effect of acute (24-h) and prolonged (14-day) drug-free periods in cocaine-experienced mice on behavioral, endocrine, and molecular outputs following stress exposure.

MATERIALS AND METHODS

Mice were administered a cocaine binge (15 mg/kg, every hour for 3h) for 2 weeks. Following a 24-h or 14-day drug-free period, stress responsivity, along with levels of anxiety, were measured using the forced swim test and elevated zero maze, respectively. In addition, alterations in the levels of plasma corticosterone, corticotrophin-releasing factor (CRF) mRNA, brain-derived neurotrophic factor (BDNF) mRNA, and histone acetylation at their respective promoters were examined following stress exposure.

RESULTS

At both acute and prolonged abstinence time points, behavioral measures were essentially unaltered; however, cocaine-experienced mice exhibited an augmented corticosterone response to the forced swim stress compared to saline-treated mice. Stress exposure increased BDNF mRNA levels in the ventral tegmental area (VTA) and nucleus accumbens (NAc) only in cocaine-experienced mice following a prolonged, but not acute, drug-free period. Increased BDNF mRNA in the NAc was associated with an increase in acetylated histone 3 (AcH3) at the BDNF I promoter. CRF mRNA levels were increased in the amygdala (AMYG); however, this was not associated with alterations in histone acetylation at the promoter.

CONCLUSION

These results demonstrate that drug history and prolonged abstinence can alter the endocrine and molecular responses to stress, which may facilitate the reinstatement of drug-seeking behaviors.

Bidirectional translational research: Progress in understanding addictive diseases

The focus of this review is primarily on recent developments in bidirectional translational research on the addictions, within the Laboratory of the Biology of Addictive Diseases at The Rockefeller University. This review is subdivided into major interacting aspects, including (a) Investigation of neurobiological and molecular adaptations (e.g., in genes for the opioid receptors or endogenous neuropeptides) in response to cocaine or opiates, administered under laboratory conditions modeling chronic patterns of human self-exposure (e.g., chronic escalating "binge"). (b) The impact of such drug exposure on the hypothalamic-pituitary-adrenal (HPA) axis and interacting neuropeptidergic systems (e.g., opioid, orexin and vasopressin). (c) Molecular genetic association studies using candidate gene and whole genome approaches, to define particular systems involved in vulnerability to develop specific addictions, and response to pharmacotherapy. (d) Neuroendocrine challenge studies in normal volunteers and current addictive disease patients along with former addicts in treatment, to investigate differential pharmacodynamics and responsiveness of molecular targets, in particular those also investigated in the experimental and molecular genetic approaches as described above.

Psychobiological responses to drug cues before and after methadone intake in heroin-dependent patients: a pilot study

Craving and stress frequently drive compulsive heroin use. Although methadone attenuates craving, drug-conditioned stimuli can trigger craving and possibly stress arousal in heroin-dependent patients receiving methadone maintenance. This study investigated drug cue-related craving, affectivity, and cortisol reactivity in 16 methadone-maintained patients before and after daily methadone. Unexpectedly, drug cues significantly increased craving after (t[15]=-4.27, p=0.001), but not before methadone intake. Patients displayed blunted cortisol response after post-methadone drug cues (t[15]=3.05, p=0.008) suggesting dissociated craving and cortisol reactivity after methadone intake of possible clinical relevance.

Opioids, dopamine, stress, and the addictions

The articulated goals of Dialogues in Clinical Neuroscience are to serve as "an interface between clinical neuropsychiatry and the neurosciences by providing state-of-the-art information and original insights into relevant clinical, biological, and therapeutic aspects." My laboratory the Laboratory of the Biology of Addictive Diseases at The Rockefeller University, has for years been focused on "bidirectional translational research," that is, learning by careful observations and study in patient populations with the disorders under study, in this case primarily specific addictive diseases, and then using that knowledge to create improved animal models or other laboratory-based research paradigms, while, at the same time, taking research findings made at the bench into the clinic as promptly as that is appropriate and feasible. In this invited review, therefore, the focus will be on perspectives of our Laboratory of the Biology of Addictive Diseases and related National Institutes of Health/National Institute on Drug Abuse research Center, including laboratory-based molecular neurobiological research, research using several animal models designed to mimic human patterns of drug abuse and addiction, as well as basic clinical research, intertwined with treatment-related research.

Making a bad thing worse: adverse effects of stress on drug addiction

Sustained exposure to various psychological stressors can exacerbate neuropsychiatric disorders, including drug addiction. Addiction is a chronic brain disease in which individuals cannot control their need for drugs, despite negative health and social consequences. The brains of addicted individuals are altered and respond very differently to stress than those of individuals who are not addicted. In this Review, we highlight some of the common effects of stress and drugs of abuse throughout the addiction cycle. We also discuss both animal and human studies that suggest treating the stress-related aspects of drug addiction is likely to be an important contributing factor to a long-lasting recovery from this disorder.

Role of a functional human gene polymorphism in stress responsivity and addictions

Over the past decade, enormous progress has been made in both the technical approaches and the scientific information available for studying the human genome. Therefore, increasingly, scientists have begun to address not just single-gene disorders but complex disorders. The limiting factor in most of such studies remains appropriate, well-focused detailed phenotyping of the complex disorders under study, with careful ascertainment of subjects with the specific disorder, as well as healthy control subjects.

Association of polymorphisms in the melanocortin receptor type 2 (MC2R, ACTH receptor) gene with heroin addiction

The melanocortin receptor type 2 (MC2R or adrenocorticotropic hormone, ACTH receptor) gene (MC2R) encodes a protein involved in regulation of adrenal cortisol secretion, important in the physiological response to stressors. A variant of MC2R, -179A>G, results in reduction of promoter activity and less adrenal action. We hypothesize that altered stress responsivity plays a key role in the initiation of substance abuse. By direct resequencing of the promoter region and exons 1 and 2 of the MC2R gene in 272 subjects including Caucasians, Hispanics and African Americans with approximately equal numbers of former heroin addicts and normal volunteers, we identified five novel variants each with allele frequency <2%. Previously reported polymorphisms -184G>A (rs2186944), -179A>G, 833A>C (rs28926182), 952T>C (rs4797825), 1005C>T (rs4797824) and 1579T>C (rs4308014) were each in allelic frequency >/=2% in one or more ethnic groups. These polymorphisms were genotyped in 632 subjects (260 Caucasians, 168 Hispanics, 183 African Americans and 21 Asians) using TaqMan assays. Significant differences in genotype frequency among ethnic groups studied were found for each of the six variants analyzed. We found a significant association (p=0.0004, experiment-wise p=0.0072) of the allele -184A with a protective effect from heroin addiction in Hispanics. Also, in Hispanics only we found the haplotype GACT consisting of four variants (-184G>A, -179A>G, 833A>C and 1005C>T) to be significantly associated with heroin addiction (p=0.0014, experiment-wise p=0.0168), whereas another haplotype, AACT, consisting of the same variants, was associated with a protective effect from heroin addiction (p=0.0039, experiment-wise p=0.0468).

Mood and neuroendocrine response to a chemical stressor, metyrapone, in buprenorphine-maintained heroin dependence

BACKGROUND

Heroin dependence is associated with a hyperactive hypothalamic-pituitary-adrenal (HPA) axis, proposed as a biological correlate of craving. Maintenance treatment with methadone normalizes HPA axis activity. Here, we examined HPA axis activity under maintenance treatment with the increasingly utilized partial opiate agonist buprenorphine.

METHODS

Responses to a metyrapone challenge were compared in 20 buprenorphine-maintained heroin addicts and 20 healthy volunteers (10 received a single 50 mg naltrexone dose [NTX+] and 10 received no naltrexone [NTX-]). Patients were 16 male subjects and 4 female subjects, aged 30 to 38 years, heroin-dependent and relapse-free under buprenorphine maintenance (BUP) for a minimum of 6 months. Healthy volunteers were 9 male subjects and 11 female subjects, aged 36 to 49 years, with no history of dependence. Serial measures were obtained of plasma adrenocorticotropic hormone (ACTH) and cortisol and Profile of Mood States (POMS) ratings over time. Subjects were genotyped for the OPRM1 118A/G polymorphism.

RESULTS

Buprenorphine maintenance showed a dampened HPA axis response to metyrapone, with OPRM1 118G carriers showing a significantly attenuated response compared with 118A carriers. The response of the NTX+ group was markedly increased. In contrast, negative affect was elevated in the BUP group but did not differ between NTX- and NTX+. Buprenorphine maintenance and NTX- groups did not differ in positive affect, whereas the NTX+ group was lower.

CONCLUSIONS

In contrast to exaggerated HPA axis responsiveness reported in untreated heroin dependence, response to metyrapone was subnormal in heroin addicts maintained on buprenorphine. Despite this, increased measures of negative affect were seen in this group. This implies a dissociation of HPA axis responsiveness and affect in heroin dependence.

Pain management in sickle cell disease: palliative care begins at birth?

People with sickle cell disease (SCD) are living longer, but their lives are impacted even more by the unpredictable intermittent or constant pain that is often poorly managed over a lifetime. To address this problem, an interdisciplinary team approach is needed that brings the medical professionals together for optimal compassionate care that is coordinated from the beginning of life and throughout the patient's lifespan.The hematologist, whenever possible, should take the lead. Effective models that have been developed to address SCD pain, such as the Day Hospital, The Recidivism Project and various Home Care models, need to be integrated into an overarching plan on a continuum with an underpinning philosophy that will sustain such a program. While the focus of palliative care has been end of life, its philosophies fit the chronic disease model and support an integrated team approach to the SCD pain management dilemma. The patient-focused and family-oriented interventions can be modeled to fit "any place, any time," outpatient, inpatient or the home, with homecare and other support systems. Such are the needs in SCD: appropriate, timely and compassionate care to prevent or relieve suffering and to preserve dignity, meaning, value and quality of life with improvement that is translational from birth until the end of life.

Childhood neglect and parental care perception in cocaine addicts: relation with psychiatric symptoms and biological correlates

Childhood neglect and poor child-parent relationships have been reported to increase substance use disorders susceptibility. Stressful environmental factors, including emotional neglect, could affect individual personality traits and mental health, possibly inducing stable changes in hypothalamic-pituitary-adrenal (HPA) axis and brain mono-amine function, in turn involved in addictive behavior vulnerability. Therefore, we decided to investigate homovanillic (HVA) and prolactin (PRL) plasma levels, as expression of possible changes in dopamine function, ACTH and cortisol plasma levels, as measures of HPA axis function, and concomitant psychiatric symptoms profile in abstinent cocaine addicts, in relationship to their childhood history of neglect and poor parental care perception.

METHODS

Fifty abstinent cocaine dependent patients, and 44 normal controls, matched for age and sex, were submitted to a detailed psychiatric assessment (DSM IV criteria). All patients and controls completed the Symptoms Check List-90 (SCL-90) and the Buss Durkee Hostility Inventory (BDHI), to evaluate psychiatric symptoms frequency and aggressiveness levels. The Childhood Experience of Care and Abuse-Questionnaire (CECA-Q) and Parental Bonding Instrument (PBI) have been used to retrospectively investigate parent-child relationships. Blood samples were collected to determine HVA, PRL, ACTH and cortisol basal plasma levels.

RESULTS

Cocaine addicted individuals in general showed significantly lower HVA, and higher PRL, ACTH and cortisol basal levels respect to controls. In particular, neuroendocrine changes characterized cocaine addicts with childhood history of neglect and low perception of parental care. Obsessive-compulsive, depression and aggressiveness symptoms have been found related to poor parenting, inversely associated to HVA levels and directly associated to PRL, ACTH and cortisol levels.

CONCLUSIONS

These findings suggest the possibility that childhood experience of neglect and poor parent-child attachment may partially contribute to a complex neurobiological derangement including HPA axis and dopamine system dysfunctions, playing a crucial role in addictive and affective disorders susceptibility.

Chronic cannabis use does not affect the normalization of hypothalamic-pituitary-adrenal (HPA) axis induced by methadone in heroin addicts

The hypothalamic-pituitary-adrenal (HPA) axis activity is usually altered by heroin use. In the present study we evaluated in one hundred twenty-one heroin addicts the effects of marijuana smoking on the normalization of HPA axis upon methadone treatment. The study showed that in heroin addicts who are chronic cannabis smokers a treatment with methadone lasting 12 months was able to normalize both plasma corticotropin (ACTH) and cortisol levels, as well as to control both heroin withdrawal symptoms and opioid craving. As expected in the same group of patients marijuana smoking and its craving were not reduced by methadone treatment. Our data confirm that methadone treatment outcomes are not modified by cannabis use and they add in the literature the evidence that chronic cannabis use is not able to affect the normalization of HPA axis upon methadone treatment in heroin addicts.

Opioid dependence and addiction during opioid treatment of chronic pain

Throughout the long history of opioid drug use by humans, it has been known that opioids are powerful analgesics, but they can cause addiction. It has also been observed, and is now substantiated by multiple reports and studies, that during opioid treatment of severe and short-term pain, addiction arises only rarely. However, when opioids are extended to patients with chronic pain, and therapeutic opioid use is not confined to patients with severe and short-lived pain, compulsive opioid seeking and addiction arising directly from opioid treatment of pain become more visible. Although the epidemiological evidence base currently available is rudimentary, it appears that problematic opioid use arises in some fraction of opioid-treated chronic pain patients, and that problematic behaviors and addiction are problems that need to be addressed. Since the potentially devastating effects of addiction can substantially offset the benefits of opioid pain relief, it seems timely to reexamine addiction mechanisms and their relevance to the practice of long-term opioid treatment for pain. This article reviews the neurobiological and genetic basis of addiction, its terminology and diagnosis, the evidence on addiction rates during opioid treatment of chronic pain and the implications of biological mechanisms in formulating rational opioid treatment regimes.

Downregulation of κ-opioid receptors in basolateral amygdala and septum of rats withdrawn for 14 days from an escalating dose “binge” cocaine administration paradigm

There is evidence showing that the opioid systems play an important role in cocaine addiction; fewer studies have examined their roles in cocaine withdrawal. This study was conducted to determine whether cocaine or chronic withdrawal from cocaine alters the receptor component of the kappa-opioid system. Male Fischer rats were injected with saline or cocaine (3x15 mg/kg/day for 4 days, 3x20 mg/kg/day for 4 days, 3x25 mg/kg/day for 4 days, and 3x30 mg/kg/day for 2 days), three times daily at 1-h intervals in an escalating dose paradigm for 14 days. Identically treated rats were withdrawn from cocaine or saline for 14 days. We performed quantitative autoradiographic mapping of kappa-opioid receptors (KOP-r) in the brains of rats treated with this escalating dose "binge" cocaine administration paradigm and of rats withdrawn from cocaine for 14 days. A significant condition (chronic/withdrawal) effect was shown across all regions analyzed. A significant increase in [3H]CI-977 binding to KOP-r was detected in the septum of rats treated with an escalating dose binge cocaine administration paradigm and killed 30 min after the last cocaine injection. In contrast, there was a decrease in KOP-r binding in the septum and the basolateral amygdala of rats withdrawn for 14 days from chronic escalating dose binge cocaine administration, compared to rats at the end of 14 days chronic escalating dose cocaine administration. These results reconfirm and extend that KOP-r undergoes upregulation in response to chronic binge cocaine administration here, with an escalating dose. The observed lowering in KOP-r binding, which was shown in two brain regions of cocaine withdrawn animals, might contribute to the persistent dysphoria reported a long time after the discontinuation of the drug.

Relationship Between Plasma Cortisol Levels, Withdrawal Symptoms and Craving in Abstinent and Treated Heroin Addicts

Twelve-month treatment of heroin addicts with methadone or buprenorphine normalized plasma cortisol levels, and controlled withdrawal symptoms as well as craving. During treatment, the time course of plasma cortisol levels and craving was not strictly correlated: heroin craving was more elevated at 12 than at 3 months. The results suggest a correlation between hypercortisolism, withdrawal symptoms and heroin use and suppose a more complex role for craving and its components in drug-taking behaviour. The main goal of the pharmacological treatment of opioid-dependence should be addressed at the normalization of hypothalamic-pituitary-adrenocortical (HPA) axis more than at the control of craving.

Cocaine and amphetamine regulated transcript (CART) and the stress response

CART is expressed abundantly in the hypothalamic paraventricular nucleus and locus coeruleus, major corticotropin releasing factor (CRF) and noradrenaline sources, respectively. There is a bidirectional relation between CART and hypothalamo-pituitary-adrenal axis activity. CART stimulates CRF, adrenocorticotropic hormone and glucocorticoid secretion, whereas CRF and glucocorticoids increase the transcriptional activity of the CART gene; adrenalectomy declines CART expression in the hypothalamus. Stress exposure modulates CART expression in hypothalamus and amygdala in rat brain in a region and sex specific manner. CART may be a mediator peptide in the interaction between stress, drug abuse, and feeding. The review discusses the established role of CART as it relates to the stress response.

Effects of high-dose methadone maintenance on cocaine place conditioning, cocaine self-administration, and mu-opioid receptor mRNA expression in the rat brain

Methadone maintenance at appropriate doses can effectively reduce cocaine abuse in heroin-dependent individuals. In the present studies, we investigated the effect of high-dose methadone maintenance cocaine conditioned place preference (CPP) and cocaine intravenous self-administration. Rats implanted with methadone-filled osmotic mini-pumps (20 and 55 mg/kg/day, SC) and conditioned with cocaine (1, 5, and 20 mg/kg, i.p.) did not express cocaine CPP. Similarly, rats implanted with methadone pumps (55 mg/kg/day) after cocaine conditioning (20 mg/kg) displayed neither spontaneous nor cocaine-precipitated (20 mg/kg, i.p.) CPP. In contrast, methadone maintenance (30 and 55 mg/kg/day, SC) did not alter the intravenous self-administration (continuous schedule of reinforcement) of various doses of cocaine (0.1, 0.5, and 2.0 mg/kg/inf). To explore neuropharmacological interactions between methadone maintenance and cocaine conditioning, we quantitatively measured mRNA levels of mu-opioid receptor (MOR) and proopiomelanocortin genes 10 days after methadone maintenance. MOR mRNA levels in both the nucleus accumbens core and frontal cortex were significantly elevated in rats exposed to cocaine during CPP conditioning. However, upregulation of MOR mRNA levels in the nucleus accumbens core were reduced by methadone maintenance in a dose-dependent manner. In conclusion, our results suggest that high-dose methadone maintenance does not alter the direct reinforcing effect of cocaine, but blocks spontaneous and cocaine-precipitated cocaine-seeking, possibly by preventing MOR alterations in the nucleus accumbens core induced by cocaine conditioning.

Glucocorticoid negative feedback in methadone-maintained former heroin addicts with ongoing cocaine dependence: dose-response to dexamethasone suppression

Combined cocaine and illicit opiate use is common. This study aimed to test the hypothesis that cocaine dependence in former heroin-addicted patients maintained on methadone treatment is associated with enhanced glucocorticoid negative feedback. Multiple dose dexamethasone suppression tests, using a conventional 2.0 mg dose, and two lower doses, 0.5 mg and 0.125 mg, were performed in 10 methadone-maintained former heroin addicts with ongoing cocaine dependence (C-MM), 10 stabilized methadone-maintained former heroin addicts with no ongoing drug or alcohol use (MM), and 22 normal volunteers (NV). At 9 hours, there was no difference in plasma adrenocorticotropin hormone (ACTH) and/or cortisol levels among groups on the baseline day, as well as after the two lower doses of dexamethasone. At 17 hours, C-MM and MM had significantly lower plasma ACTH and/or cortisol levels than NV. However, C-MM did not significantly differ from MM in their hormonal levels. When the hormonal responses to dexamethasone are expressed as magnitude of lowering from baseline, there was no significant difference at any dose among groups. Therefore, C-MM exhibited a normal glucocorticoid negative feedback in the morning. Using the standard interpretation of dexamethasone suppression testing based on the examination of the actual hormonal levels rather than the difference from baseline condition, C-MM appear to have glucocorticoid effects similar to MM, yet were both greater than NV in the late afternoon. Thus, further studies are needed to know whether altered glucocorticoid negative feedback is related to chronic cocaine exposure, or is the result of former heroin addiction and/or its long-term treatment with methadone.

Genetic influences on impulsivity, risk taking, stress responsivity and vulnerability to drug abuse and addiction

Genetic variation may partially underlie complex personality and physiological traits--such as impulsivity, risk taking and stress responsivity--as well as a substantial proportion of vulnerability to addictive diseases. Furthermore, personality and physiological traits themselves may differentially affect the various stages of addiction, defined chronologically as initiation of drug use, regular drug use, addiction/dependence and potentially relapse. Here we focus on recent approaches to the study of genetic variation in these personality and physiological traits, and their influence on and interaction with addictive diseases.

Amygdalar vasopressin mRNA increases in acute cocaine withdrawal: evidence for opioid receptor modulation

In humans, stress is recognized as a major factor contributing to relapse to drug abuse in abstinent individuals; drugs of abuse themselves or withdrawal from such drugs act as stressors. In the animals, evidence suggests that centrally released arginine vasopressin in both amygdala and hypothalamus plays an important role in stress-related anxiogenic behaviors. The stress responsive hypothalamic-pituitary-adrenal axis is under tonic inhibition via endogenous opioids, and cocaine withdrawal stimulates hypothalamic-pituitary-adrenal activity. The present studies were undertaken to determine whether: (1) 14-day (chronic) "binge" pattern cocaine administration (45 mg/kg/day) or its withdrawal for 3 h (acute), 1 day (subacute) or 10 days (chronic) alters arginine vasopressin mRNA levels in amygdala or hypothalamus; (2) the opioid receptor antagonist naloxone (1mg/kg) alters arginine vasopressin mRNA or hypothalamic-pituitary-adrenal hormonal responses in acute cocaine withdrawal; and (3) there are associated changes of mu opioid receptor or proopiomelanocortin mRNA levels. In amygdala, arginine vasopressin mRNA levels were unchanged after chronic "binge" cocaine, but were increased during acute cocaine withdrawal. Naloxone completely blocked this increase. Neither chronic cocaine nor its acute withdrawal altered amygdalar mu opioid receptor mRNA levels. The increase in amygdalar arginine vasopressin mRNA levels was still observed after subacute withdrawal, but not after chronic withdrawal. Although hypothalamic-pituitary-adrenal tolerance developed with chronic "binge" cocaine, there were modestly elevated plasma adrenocorticotropin hormone levels during acute withdrawal. While naloxone produced modest adrenocorticotropin hormone elevations in cocaine-naïve rats, naloxone failed to elicit an adrenocorticotropin hormone response in cocaine-withdrawn rats. In hypothalamus, neither chronic cocaine nor acute withdrawal altered arginine vasopressin, proopiomelanocortin or mu opioid receptor mRNA levels. These results show that: (1) opioid receptors mediate increased amygdalar arginine vasopressin gene expression during acute cocaine withdrawal, and (2) cocaine withdrawal renders the hypothalamic-pituitary-adrenal axis insensitive to naloxone. Our findings suggest a potential role for amygdalar arginine vasopressin in the aversive consequences of early cocaine withdrawal.

Repeated psychological stress testing in stimulant-dependent patients

Decreasing response to stress has been one goal of interventions aimed at reducing relapse to substances of abuse. A laboratory stress test that can be repeated would be helpful in testing the efficacy of interventions in decreasing the response to stress before more extensive trials are begun. The effects of two types of psychological stress tests, the Trier Social Stress Test (TSST) and a stress imagery test, on psychological, physiological, and hormonal responses (salivary cortisol and DHEA) were examined when each test was given twice to cocaine- or methamphetamine-dependent human subjects, 24 of whom completed at least one session. The stress imagery test produced significant changes in several of the subjective response measures in both first and second sessions, including several measures of negative affect and a craving measure. The TSST produced significant changes only in the second session. The stress imagery protocol showed better replicability across two sessions. Cocaine users and methamphetamine users did not respond similarly in their craving responses. Reported craving for methamphetamine after stress testing showed decreases or much smaller increases compared to that for cocaine. Neither stress test significantly increased salivary cortisol or DHEA, and changes in hormone concentrations were not related to subjective responses. These results suggest that stress imagery testing procedures may be useful as provocative tests of stress-induced affect and stimulant drug craving. Although less convincing because of the heterogeneity of the subjects, they also suggest that HPA axis responsivity is not clearly linked to acute stress-induced stimulant craving or affective response.