Association between Blood Level of Plasma Oxytocin and Novelty Seeking among Methadone-Maintained Heroin Users

The Effectiveness of Oxytocin for Treating Substance Use Disorders:A Systematic Review of Randomized Placebo-controlled Trials

Oxytocin is gaining traction in the treatment of various substance use disorders (SUD). We performed a systematic review assessing the efficacy of oxytocin for treating different SUD. The electronic databases MEDLINE, EMBASE, CENTRAL, and the Cochrane Database of Systematic Reviews were searched for randomized controlled trials examining the effects of oxytocin vs. placebo in SUD samples. Quality assessment was conducted using a Cochrane validated checklist. A total of 17 trials with unique samples were identified. These were conducted on participants with SUD involving alcohol (n = 5), opioids (n = 3), opioids and/or cocaine/other stimulants (n = 3), cannabis (n = 2), or nicotine (n = 4). Across the SUD-groups, oxytocin reduced withdrawal symptoms (3/5 trials), negative emotional states (4/11 trials), cravings (4/11 trials), cue-induced cravings (4/7 trials), and consumption (4/8 trials). Sixteen trials had an overall considerable risk of bias. In conclusion, although oxytocin showed some promising therapeutic effects, the findings are too inconsistent and the trials too heterogeneous to derive any firm conclusions. Sounder methodological and well-powered trials are warranted.

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.

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).

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.

Non-overlapping and Inverse Associations Between the Sexes in Structural Brain-Trait Associations

Personality reflects the set of psychological traits and mechanisms characteristic for an individual. The brain-trait association between personality and gray matter volume (GMv) has been well studied. However, a recent study has shown that brain structure-personality relationships are highly dependent on sex. In addition, the present study investigates the role of sex on the association between temperaments and regional GMv. Sixty-six participants (33 male) completed the Temperament and Character Inventory (TCI) and underwent structural magnetic resonance brain imaging. Mann-Whitney U tests showed a significant higher score on Novelty Seeking (NS) and Reward Dependence (RD) for females, but no significant group effects were found for Harm Avoidance (HA) and Persistence (P) score. Full factor model analyses were performed to investigate sex-temperament interaction effects on GMv. This revealed increased GMv for females in the superior temporal gyrus when linked to NS, middle temporal gyrus for HA, and the insula for RD. Males displayed increased GMv compared to females relating to P in the posterior cingulate gyrus, the medial superior frontal gyrus, and the middle cingulate gyrus, compared to females. Multiple regression analysis showed clear differences between the brain regions that correlate with female subjects and the brain correlates that correlate with male subjects. No overlap was observed between sex-specific brain-trait associations. These results increase the knowledge of the role of sex on the structural neurobiology of personality and indicate that sex differences reflect structural differences observed in the normal brain. Furthermore, sex hormones seem an important underlying factor for the found sex differences in brain-trait associations. The present study indicates an important role for sex in these brain structure-personality relationships, and implies that sex should not just be added as a covariate of no interest.

Pathways Relating the Neurobiology of Attachment to Drug Addiction

Substance use disorders constitute a significant public health problem in North America and worldwide. Specifically, substance addictions in women during pregnancy or in the postpartum period have adverse effects not only on the mother, but also on mother-infant attachment and the child's subsequent development. Additionally, there is growing evidence suggesting that parental addiction may be transmitted intergenerationally, where the child of parents with addiction problems is more likely to experience addiction as an adult. The current review takes a developmental perspective and draws from animal and human studies to examine how compromised early experience, including insecure attachment, early abuse/neglect, and unresolved trauma, may influence the development of neurobiological pathways associated with addictions, ultimately increasing one's susceptibility to addictions later in life. We approach this from three different levels: molecular, neuroendocrine and behavioral; and examine the oxytocin affiliation system, dopamine reward system, and glucocorticoid stress response system in this regard. Increased understanding of these underlying mechanisms may help identify key targets for early prevention efforts and inform needed intervention strategies related to both insecure attachment and addiction.

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.

Gray Matter Volume of a Region in the Thalamic Pulvinar Is Specifically Associated with Novelty Seeking

Personality reflects the set of psychological traits and mechanisms characteristic for an individual. Geno-neuro-biologically inspired personality accounts have proposed a set of temperaments and characters that jointly compose personality profiles. The present study addresses the link between neurobiology and personality and investigates the association between temperament traits and regional gray matter volume. Furthermore, the specificity of these associations as well as the underlying components that drive the association are addressed. One hundred and four participants completed the Temperament and Character Inventory (TCI) and underwent structural magnetic resonance brain imaging. The participants included premanifest carriers of Huntington's disease, as this population is associated with temperament-related neuropsychiatric symptoms. Whole brain voxel-based multiple regression analyses on gray matter volume revealed a significant specific positive correlation between a region in the left thalamic pulvinar and novelty seeking score, controlled for the other traits (P_height < 0.05, FWE-corrected). No significant associations were observed for the other temperament traits. Region of interest analyses showed that this association is driven by the subscale NS2: impulsiveness. The results increase the knowledge of the structural neurobiology of personality and indicate that individual differences in novelty seeking reflect the structural differences observed in the brain in an area that is widely and densely connected, which is in line with the typically domain-general behavioral influence of personality traits on a wide range of affective, perceptual, mnemotic, executive, and other cognitive functions.

Decreased Blood Levels of Oxytocin in Ketamine-Dependent Patients During Early Abstinence

Background: Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, is a common drug of abuse worldwide. Existing evidence suggest a disruption of oxytocin system involves in the development of addiction. In this study, we aimed to investigate the role of oxytocin in ketamine addiction by measuring the blood oxytocin levels in ketamine-dependent (KD) patients. Methods: Sixty-five KD patients and 65 controls were enrolled. Fasting plasma levels of oxytocin were determined at baseline and 1 and 2 weeks after ketamine withdrawal. Ketamine use variables, Beck Depression Inventory, Beck Anxiety Inventory (BAI), Visual Analog Scale for craving, and Childhood Trauma Questionnaire-short form were assessed in KD patients. Results: KD patients had significantly lower levels of oxytocin at baseline compared to controls (5.89 ± 2.13 vs. 9.53 ± 4.17 ng/mL, P < 0.001). Oxytocin levels increased after one (6.74 ± 2.63, P < 0.002) and 2 weeks (6.89 ± 2.69, P = 0.01) of withdrawal in KD patient despite the levels were still lower than controls (P = 0.001 and 0.002, respectively). The clinical variables did not correlate with baseline oxytocin levels except BAI scores, which showed a negative correlation with the levels (r = -0.263; P = 0.039). Conclusion: We found a distinctively reduced oxytocin level in KD patients and the level did not normalize after early abstinence. Lower oxytocin might be associated with anxious phenotype of ketamine dependence. These results suggest that oxytocin system dysregulated following chronic ketamine abuse and might provide insight in evaluating the potential therapeutic use of oxytocin for treating ketamine dependence.

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.

Severity of Withdrawal Symptoms, Plasma Oxytocin Levels, and Treatment Outcome in Heroin Users Undergoing Acute Withdrawal

Pre-clinical studies show that, following chronic opioid exposure, oxytocin neurons exhibit over-excitation upon withdrawal, causing an increase in oxytocin brain and plasma levels. Relevant clinical data on humans are scarce. This study investigates the opioid withdrawal stress effect on oxytocin plasma levels in humans. We evaluated 57 male chronic heroin users in a residential detoxification program. We determined plasma oxytocin levels by ELISA and measured the stress effects of withdrawal using the COWS scale for opioid withdrawal, the VAS scale for craving, and the Hamilton scales for anxiety and depression on the second day of admission. Out of the 57 patients enrolled in the study, 27 completed the 21-day program, while the remaining 30 dropped out prior to completion. Plasma oxytocin levels were significantly higher in those individuals who dropped out than in those who completed the program. Participants who dropped out at some stage scored higher in the COWS, VAS-Craving, and Hamilton-anxiety scales, indicating a higher stress and explaining the higher oxytocin levels. In addition, plasma oxytocin levels correlated positively with the scores achieved in the COWS and Hamilton-anxiety scales. Higher withdrawal stress levels are associated with higher plasma oxytocin levels and early treatment discharge.

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

A disruption of the oxytocin system seems to affect a variety of brain functions including emotions, mood and social behavior possibly underlying severe social deficits and susceptibility for substance use and mental health disorders. Early life adversity, such as insecure attachment in childhood, has been suggested to influence oxytocin tone contributing to a condition of neurobiological vulnerability. Aim of the present study was to investigate oxytocin serum levels in abstinent heroin addicted patients, in comparison with healthy controls, and the possible correlation with co-occurring psychiatric symptoms, aggressiveness and perception of parental neglect. Eighteen (18) abstinent patients, affected by heroin use disorders, and 18 control subjects, who never used drugs or abused alcohol, were included in the study and submitted to 1) collection of a blood sample for oxytocin assay, 2) Symptoms Check List 90 for psychiatric symptoms evaluation 3) Buss Durkee Hostility Inventory to measure aggressiveness 4) Child Experience of Care and Abuse-Questionnaire to retrospectively test the perception of parental neglect. Heroin exposure extent and heroin dosages were also recorded. Oxytocin serum levels were unexpectedly significantly higher among abstinent patients affected by heroin use disorders and positively correlated with psychiatric symptoms, aggressiveness and mother neglect scores. No correlation was evidenced between oxytocin and heroin exposure extent or dosages. Our findings appear to contradict the simplistic view of oxytocin as a pro-social hormone and confirm previous evidence concerning the peptide levels direct association with aggressive behavior and mood disorders. Considering a more complex mechanism, oxytocin would increase the sensitivity to social salience cues related to contextual or inter-individual factors, promoting pro-sociality in "safe" conditions and, in contrast, inducing more defensive and "anti-social" emotions and behaviors when the social cues are interpreted as "unsafe". This latter condition is often characterizing the clinical history of addicted patients.

A two-week pilot study of intranasal oxytocin for cocaine-dependent individuals receiving methadone maintenance treatment for opioid use disorder

30-60% of patients receiving methadone for opioid use disorder (OUD) actively use cocaine. Cocaine use disorder (CUD) has no FDA-approved pharmacological treatment; existing psychosocial treatments are inadequate. Oxytocin, a social neuropeptide, has preclinical promise as an adjunctive treatment for both OUD and CUD. Twenty-two individuals receiving methadone for OUD with co-occurring CUD were randomized to receive oxytocin or placebo intranasally 40 IU twice daily for two weeks. A priori aims were feasibility and safety. Exploratory effectiveness aims included laboratory-based measures of drug craving, drug-related implicit cognition, and drug use. High retention rates (93.5%), the absence of study-related adverse events, and the fact that oxytocin was well tolerated in this population support the feasibility of larger trials. Two weeks of oxytocin (but not placebo) significantly reduced cocaine craving at day 15 compared to baseline (mean change±SD: OT=-0.23±0.19, p=0.004; PL=-0.16±0.29, p=0.114). For heroin craving, the placebo group reported a trend-level increase over time while the oxytocin group remained unchanged - with medium to large effect sizes between the groups (Cohen's d=0.71-0.90). Oxytocin led to a significant switch from implicit self-association with drugs to implicitly associating drugs with others (mean change±SD: 0.25±0.35, p=0.037) and a trend-level reduction in self-reported cocaine use over time (Z=-1.78, p=0.075). Furthermore, oxytocin significantly increased the accuracy of self-reported cocaine use when correlated with quantitative urine levels of cocaine metabolite. This proof-of-concept study provides promising early evidence that oxytocin may be an effective adjunct to the treatment of co-occurring CUD and OUD. Further investigation with larger trials is warranted.