Increased oxytocin levels among abstinent heroin addicts: Association with aggressiveness, psychiatric symptoms and perceived childhood neglect

Cocaine use disorder effects on blood oxytocin levels and OXTR DNA methylation

Substance use disorders have been associated with alterations in the oxytocinergic system, but few studies have investigated both the peptide and epigenetic mechanisms potentially implicated in the regulation of oxytocin receptor. In this study, we compared plasma oxytocin and blood DNA methylation in the OXTR gene between people with and without cocaine use disorder (CUD). We measured the oxytocin levels of 51 people with CUD during acute abstinence and of 30 healthy controls using an enzyme immunoassay. The levels of DNA methylation in four CpG sites at exon III of the OXTR gene were evaluated in a subsample using pyrosequencing. The Addiction Severity Index was used to assess clinical characteristics. We found higher oxytocin levels in men with CUD (56.5 pg/mL; 95% CI: 48.2-64.7) than in control men (33.6 pg/mL; 95% CI: 20.7-46.5), while no differences between women with and without CUD were detected. With a moderate effect size, the interaction effect between group and sex remained significant when controlling for height, weight and age data. A positive correlation in the CUD sample was found between oxytocin levels and days of psychological suffering prior to treatment enrollment. No group differences were observed regarding DNA methylation data. This suggests that CUD is associated with higher peripheral oxytocin levels in men during acute abstinence. This finding may be considered in future studies that aim at using exogenous oxytocin as a potential treatment for cocaine addiction.

Oxytocin level among patients with opioid use disorder and its correlation with personality traits and perceived childhood trauma

Background

Personality traits and perceived childhood maltreatment are of the predictors of substance use disorder development. Many studies have discussed oxytocin effect on personality traits and its relation with childhood trauma and how both affect the addictive process. The main aim was to compare oxytocin level between patients with opioid use disorder and controls and the potential association of oxytocin level with the basic dimensions of personality traits and perceived childhood adverse experiences in patients group. Forty male patients with opioid use disorder and 40 healthy controls matched in age and gender were assessed and compared regarding serum oxytocin level by ELISA, personality traits using Temperament and character inventory - revised (TCI- R) scale, and childhood adverse events using childhood trauma questionnaire.

Results

A significant difference between the patient group and the control group regarding the serum oxytocin level was found. Negative correlation with p-value <0.05 between oxytocin level and each of novelty seeking, and harm avoidance, in addition to a positive correlation between oxytocin level and each of reward dependence, self-directedness, and cooperativeness items of (TCR-R), among cases were found. Cases did not show statistically significant difference in oxytocin level between different Childhood Trauma Questionnaire (CTQ) items.

Conclusions

The interaction between serum oxytocin levels, personality traits, and childhood trauma has to be considered in management with heroin-dependent patients as it plays a crucial role.

Beta-Endorphin and Oxytocin in Patients with Alcohol Use Disorder and Comorbid Depression

Background: The neuropeptides β-endorphin and oxytocin are released into the bloodstream as hormones from the pituitary gland but also have an important function as neuroregulators in the forebrain. The blood levels of both polypeptides have been shown to reflect depressive symptoms. β-Endorphin, in particular, is also involved in abstinence from alcohol. Methods: The serum levels of β-endorphin and oxytocin were measured during the early withdrawal phase in patients with alcohol use disorder (AUD) with (N = 35) or without (N = 45) depressive comorbidity and compared with those in healthy volunteers (N = 23). In addition to comparing the groups, the study examined whether serum levels correlated with various psychometric measures of dependence, depression and aggression, as well as with clinical characteristics of dependence. Results: Both serum levels of beta-endorphin and oxytocin were significantly lower in patients than those in healthy controls (p = 0.011 for β-endorphin and p = 0.005 for oxytocin, Kruskal–Wallis test). In patients with depressive comorbidity, the significance was greatest (p = 0.005 for β-endorphin and p = 0.004 for oxytocin, U-test). There was no correlation with clinical or psychometric parameters (p > 0.05, Spearman test), but beta-endorphin levels did correlate significantly with physical aggression (p = 0.026, Spearman test). Conclusions: Serum levels of β-endorphin and oxytocin are lower in patients with AUD, particularly in those with depressive comorbidity. β-Endorphin levels correlated with physical aggression according to the Buss–Durkee (BDHI) estimates.

Alcohol use disorders among adult children of alcoholics (ACOAs): Gene-environment resilience factors

Both genetic and early environmental factors contribute to the pathogenesis of Alcohol Use Disorder (AUD). Gender and psychopathology symptoms might further moderate this association, resulting in an impairment of both the dopaminergic and serotoninergic pathways that sustain the binge, withdrawal and craving cycle. In a sample of of adult children of alcoholic parents (ACOAs) (n = 107) we compared those with and without an AUD, on socio-demographic variables, adverse childhood experiences, psychopathology symptoms and two polymorphisms associated with an impaired serotoninergic and dopaminergic neurotransmission (5HTTLPR and Taq1A/DRD2). A logistic regression revealed that an early caring environment might lower the risk of developing an AUD. When controlling for the actual psychopathology symptoms, being male and having the genotype associated with an impaired dopaminergic neurotransmission were still associated with AUD. Results were confirmed by an unsupervised approach that showed how the clusters characterised by being male and having the high risk genotypes were still associated with AUD compared to being female without the unfavourable dopamine genotype.Our results point to the need for implementing prevention strategies aimed at creating a caring environment especially in those families with an alcoholic parent. We further suggest that psycho-education as a symptom recognition and avoiding self-medication could improve the outcome in those subjects at higher risk, especially males.

The potential role of oxytocin in addiction: What is the target process?

Oxytocin regulates a variety of centrally-mediated functions, ranging from socio-sexual behavior, maternal care, and affiliation to fear, stress, anxiety. In the past years, both clinical and preclinical studies characterized oxytocin for its modulatory role on reward-related neural substrates mainly involving the interplay with the mesolimbic and mesocortical dopaminergic pathways. This suggests a role of this nonapeptide on the neurobiology of addiction raising the possibility of its therapeutic use. Although far from a precise knowledge of the underlying mechanisms, the putative role of the bed nucleus of the stria terminalis as a key structure where oxytocin may rebalance altered neurochemical processes and neuroplasticity involved in dependence and relapse has been highlighted. This view opens new opportunities to address the health problems related to drug misuse.

Opioids and the hormone oxytocin

The neuropeptide Oxytocin (ΟΤ) is involved as a neurohormone, a neurotransmitter, or a neuromodulator in an extensive range of central and peripheral effects, complex emotional and social human behaviors, memory and learning processes. It is implicated in homeostatic, neuroadaptive processes associated with stress responses and substance use via interactions with the hypothalamic-pituitary-adrenal (HPA) axis and the dopamine mesolimbic reward stress system. This chapter reviews the preclinical and clinical literature on the complicated relationships between endogenous and exogenous opioids and ΟΤ systems and attempts to highlight key findings to date on the effectiveness of intranasal OT administration to treat opioid use disorders. OΤ seems to attenuate, even inhibit, the development of opioid use disorders in preclinical models but is still under clinical research as a promising pharmacological agent in the treatment of opioid use related behaviors. Evidence suggests a role for OT as an adjunctive or stand-alone treatment of behavioral, cognitive and emotional deficits associated with substance use, which may be responsible for seeking behavior and relapse. The mechanisms by which oxytocin acts to reverse the neural substrates of these deficits, partially due to substance induced alterations of the endogenous OT system, and thus modify the behavioral response to substance use are discussed. Other clinically relevant issues are also discussed.

The impact of early life stress on the central oxytocin system and susceptibility for drug addiction: Applicability of oxytocin as a pharmacotherapy

Early life trauma is strongly associated with an increased vulnerability to abuse illicit drugs and the impairment of neural development. This includes alterations to the development of the oxytocin system, which plays a pivotal role in the regulation of social behaviours and emotion. Dysregulation of this important system also contributes to increased susceptibility to develop drug addiction. In this review, we provide an overview of the animal models of early life stress that are widely used, and discuss the impact that early life stress has on drug-taking behaviour in adolescence and adulthood in both sexes. We link this to the changes that early life stress has on the endogenous oxytocin system, and how exogenously administered oxytocin may help to re-establish functioning of the system, and in turn, reduce drug-taking behaviour.

Emotional neglect in childhood shapes social dysfunctioning in adults by influencing the oxytocin and the attachment system: Results from a population-based study

Early life maltreatment (ELM) is the major single risk factor for impairments in social functioning and mental health in adulthood. One of the most prevalent and most rapidly increasing forms of ELM is emotional neglect. According to bio-behavioral synchrony assumptions, the oxytocin and attachment systems play an important mediating role in the interplay between emotional neglect and social dysfunctioning. Therefore, the aim of the present study was to investigate whether fear and avoidance of social functioning, two important and highly prevalent facets of social dysfunctioning in adulthood, are shaped by emotional neglect, plasma oxytocin levels and attachment representations. We assessed emotional neglect as well as other forms of ELM with the Childhood Trauma Questionnaire, current attachment representations with the Adult Attachment Projective Picture System, and fear and avoidance of social situations with the Liebowitz Social Anxiety Scale in a population-based sample of N = 121 men and women. Furthermore, 4.9 ml blood samples were drawn from each participant to assess peripheral plasma oxytocin levels. Applying a sequential mediation model, results revealed that emotional neglect was associated with lower plasma oxytocin levels which in turn were associated with insecure attachment representations which were related to elevated fear and avoidance of social situations (a₁d₂₁b₂: F_3,117 = 20.84, P < .001). Plasma oxytocin and current attachment representations hence fully and sequentially mediate the effects of emotional neglect on social fear and avoidance, two important facets of adult social dysfunctioning, confirming bio-behavioral synchrony assumptions.

Medications for alcohol use disorders: An overview

Patients who suffer from alcohol use disorders (AUDs) usually go through various socio-behavioral and pathophysiological changes that take place in the brain and other organs. Recently, consumption of unhealthy food and excess alcohol along with a sedentary lifestyle has become a norm in both developed and developing countries. Despite the beneficial effects of moderate alcohol consumption, chronic and/or excessive alcohol intake is reported to negatively affect the brain, liver and other organs, resulting in cell death, organ damage/failure and death. The most effective therapy for alcoholism and alcohol related comorbidities is alcohol abstinence, however, chronic alcoholic patients cannot stop drinking alcohol. Therefore, targeted therapies are urgently needed to treat such populations. Patients who suffer from alcoholism and/or alcohol abuse experience harmful effects and changes that occur in the brain and other organs. Upon stopping alcohol consumption, alcoholic patients experience acute withdrawal symptoms followed by a protracted abstinence syndrome resulting in the risk of relapse to heavy drinking. For the past few decades, several drugs have been available for the treatment of AUDs. These drugs include medications to reduce or stop severe alcohol withdrawal symptoms during alcohol detoxification as well as recovery medications to reduce alcohol craving and support abstinence. However, there is no drug that completely antagonizes the adverse effects of excessive amounts of alcohol. This review summarizes the drugs which are available and approved by the FDA and their mechanisms of action as well as the medications that are under various phases of preclinical and clinical trials. In addition, the repurposing of the FDA approved drugs, such as anticonvulsants, antipsychotics, antidepressants and other medications, to prevent alcoholism and treat AUDs and their potential target mechanisms are summarized.

The Association between the Level of Plasma Oxytocin and Craving among Former Heroin Users

BACKGROUND

Animal studies have demonstrated that oxytocin can influence addiction behaviors and might interact with the dopaminergic system, which is a key component of addiction behaviors. However, related evidence from clinical studies is scarce. The aim of our study was to explore the relationship between plasma oxytocin level and heroin craving among patients receiving methadone maintenance treatment, and to ascertain whether this relationship is moderated by novelty-seeking.

METHODS

The study was conducted in a methadone maintenance therapy clinic of a medical center in Taiwan. Seventy-seven patients with heroin addiction were enrolled. Plasma oxytocin was measured using an ELISA kit. Craving was assessed using an established instrument, the Chinese Craving Scale.

RESULTS

A significant negative association was found between the plasma oxytocin level and craving score, which remained robust after controlling the effects of social support and low-density lipoprotein cholesterol. An interaction between oxytocin and novelty-seeking indicated that this relationship was stronger among patients with a lower level of novelty-seeking.

CONCLUSION

This finding may be taken into account in future studies and may provide a basis for the development of potential treatment for addiction. The effect of oxytocin for the treatment of opioid dependence might be modulated by some psychological factors.

Oxytocin, Tolerance, and the Dark Side of Addiction

Substance use disorders blight the lives of millions of people and inflict a heavy financial burden on society. There is a compelling need for new pharmacological treatments as current drugs have limited efficacy and other major drawbacks. A substantial number of animal and recent clinical studies indicate that the neuropeptide, oxytocin, is a particularly promising therapeutic agent for human addictions, especially alcohol use disorders. In preliminary trials, we found that oxytocin administered by the intranasal route, which produces some neuropeptide penetration into the CNS, potently blocked withdrawal and reduced alcohol consumption in heavy drinkers. A considerable body of earlier animal studies demonstrated that oxytocin inhibits tolerance to alcohol, opioids, and stimulants as well as withdrawal from alcohol and opioids. Based on these preclinical findings and our clinical results, we hypothesize that oxytocin may exert therapeutic effects in substance dependence by the novel mechanism of diminishing established tolerance. A newer wave of studies has almost unanimously found that oxytocin decreases self-administration of a number of addictive substances in several animal models of addiction. Reduction of established tolerance should be included among the potential explanations of oxytocin effects in these studies and changes in tolerance should be examined in future studies in relationship to oxytocin influences on acquisition and reinstatement of self-administration as well as extinction of drug seeking. Oxytocin efficacy in reducing anxiety and stress responses as well as established tolerance suggests it may be uniquely effective in reducing negative reinforcement (Koob's "dark side" of addiction) that maintains chronic substance use.