Effects of Intranasal Oxytocin on Stress-Induced Cigarette Craving in Daily Smokers

Could intranasal oxytocin enhance the effects of psychotherapy in individuals with mental disorders? A systematic review and meta-analysis

Interest in the therapeutic potential of oxytocin for the treatment of mental health disorders, especially those involving social dysfunction, has increased considerably in recent years. To date, most studies have only evaluated oxytocin as monotherapy, with highly inconsistent results. A new line of research is exploring the effects of combining oxytocin with psychotherapy. The aim of the present review was to evaluate the therapeutic effects of intranasal oxytocin combined with psychotherapy in individuals with psychiatric disorders. Only randomized clinical trial design was eligible for inclusion. A search of relevant databases yielded 2480 articles published through April 30, 2024. Of these, 13 trials (518 participants) were included in this review and 4 of them in a meta-analysis. The trials evaluated a range of different psychotherapeutic interventions, oxytocin doses, and mental disorders. Overall, the trials suggested that combined treatment reduced negative mental representations, decreased stress, and increased therapeutic alliance. Meta-analysis showed that combined treatment significantly reduced depressive symptoms (d= -1.58, 95 % CI: -3.15 to -0.01). However, the treatment with oxytocin had no significant effects on psychiatric symptoms (d= 0.00, 95 % CI: -0.56-0.57) or social functioning (d = 0.21, 95 % CI: -0.07-0.49). Limitations included the heterogeneity and limited sample sizes of the trials. The findings suggest that the combination of intranasal oxytocin and psychotherapy may be an effective therapeutic approach to reduce depressive symptoms in individuals with mental disorders and may improve retention and therapeutic alliance.

Oxytocin decreases alcohol self-administration in male baboons

The neurohormone oxytocin (OT) has been proposed as a treatment for alcohol and nicotine use disorders. The aim of the present study was to examine whether intravenous (IV) OT decreases alcohol oral self-administration and consumption in nonhuman primates under a 6-h alcohol access procedure as well as alcohol and nicotine (IV) self-administration under 6-h concurrent access conditions. The subjects were five male baboons (Papio anubis) that self-administered oral alcohol (4% w/v) during 6-h sessions under a fixed ratio 3 (FR3) schedule per drink. Baseline levels of alcohol self-administration were established and then OT treatment was initiated. A single dose of OT (20, 40, 80, 120 IU, IV) or its vehicle (saline) was administered before and again in the middle of the 6-h drinking session for 5 consecutive days (total oxytocin dose of 40, 80, 160, 240 IU/day). After each 5-day treatment, baseline levels of alcohol self-administration were reestablished before the next 5-day OT treatment. In addition, the effect of OT on concurrent alcohol and IV nicotine self-administration was explored in 3 of the baboons where alcohol and nicotine were concurrently available during the 6-hr session each under an FR3 schedule for each drug. Establishment of baseline self-administration and 5-day OT treatments were completed as in the alcohol only study. There was a significant overall reduction in alcohol consumption with OT compared to placebo. On post-hoc analysis, after correcting for multiple comparisons, the 40 and 80 IU doses of OT significantly reduced alcohol consumption compared with vehicle, and consumption did not vary significantly within each 5-day treatment period. OT, qualitatively, also reduced the coadministration of both alcohol and nicotine in each baboon for at least one of the OT doses administered. These results underscore the therapeutic potential of oxytocin as a treatment of alcohol use disorder and possibly, co-use of nicotine.

Advancements in addressing drug dependence: A review of promising therapeutic strategies and interventions

Substance dependence represents a pervasive global concern within the realm of public health. Presently, it is delineated as a persistent and recurrent neurological disorder stemming from drug-triggered neuroadaptations in the brain's reward circuitry. Despite the availability of various therapeutic modalities, there has been a steady escalation in the mortality rate attributed to drug overdoses. Substantial endeavors have been directed towards the exploration of innovative interventions aimed at mitigating cravings and drug-induced repetitive behaviors. Within this review, we encapsulate the most auspicious contemporary treatment methodologies, accentuating meta-analyses of efficacious pharmacological and non-pharmacological approaches: including gabapentin, topiramate, prazosin, physical exercise regimens, and cerebral stimulation techniques.

The interaction of oxytocin and nicotine addiction on psychosocial stress: an fMRI study

The anxiolytic effect of oxytocin (OXT) on psychosocial stress has been well documented, but the effectiveness under the interference of other factors still requires in-depth research. Previous studies have shown that nicotine addiction interacts with OXT on psychosocial stress on the behavioral level. However, the underlying neural mechanism of interaction between OXT and nicotine addiction on psychosocial stress has not been examined, and we conducted two experiments to reveal it. Firstly, after intranasal administration of randomized OXT or placebo (saline), a group of healthy participants (n = 27) and a group of smokers (n = 26) completed the Montreal Imaging Stress Task (MIST) in an MRI scanner. Secondly, a group of smokers (n = 22) was recruited to complete a transcranial direct current stimulation (tDCS) experiment, in which anodal tDCS was applied on subjects' anterior right superior temporal gyrus (rSTG). In both experiment, subjective stress ratings, salivary cortisol samples and the amount of daily cigarette consumption were obtained from each participant. Analysis of variance were applied on both behavioral and neural data to examine the effects of OXT and nicotine addiction, and correlation analysis were used to examine relationships between neural and behavioral data. In first fMRI experiment, analysis of variance (ANOVA) revealed an interaction of OXT and nicotine addiction on subjective stress. In smokers, OXT failed to suppress the elevation of subjective stress and craving ratings after psychosocial stress. A voxel-wise ANOVA of fMRI data identified an interaction between OXT and nicotine addiction in anterior rSTG, and its functional connectivity with right middle frontal gyrus. Correlations between this functional connectivity and subjective psychosocial stress were also found abnormal in smokers. In second tDCS experiment, we found that under tDCS, OXT successfully suppressed the elevation of subjective stress and craving ratings after stress. In summary, we found that nicotine addiction blocked OXT's anxiolytic on psychosocial stress, which was related to abnormalities in anterior rSTG. By applying anodal tDCS on anterior rSTG, OXT's anxiolytic effect was restored in smokers. These findings will support further development on oxytocin's intervention of psychosocial stress in nicotine addiction, and provides essential information for indicating OXT's effectiveness.

Neurobiology of Stress-Induced Nicotine Relapse

Tobacco smoking is the leading cause of preventable death and disease. Although there are some FAD-approved medicines for controlling smoking, the relapse rate remains very high. Among the factors that could induce nicotine relapse, stress might be the most important one. In the last decades, preclinical studies have generated many new findings that lead to a better understanding of stress-induced relapse of nicotine-seeking. Several molecules such as α3β4 nicotinic acetylcholine receptor, α2-adrenergic receptors, cannabinoid receptor 1, trace amine-associated receptor 1, and neuropeptide systems (corticotropin-releasing factor and its receptors, dynorphine and kappa opioid receptor) have been linked to stress-induced nicotine relapse. In this review, we discuss recent advances in the neurobiology, treatment targets, and potential therapeutics of stress-induced nicotine relapse. We also discuss some factors that may influence stress-induced nicotine relapse and that should be considered in future studies. In the final section, a perspective on some research directions is provided. Further investigation on the neurobiology of stress-induced nicotine relapse will shed light on the development of new medicines for controlling smoking and will help us understand the interactions between the stress and reward systems in the brain.

Methylation of the Oxytocin, Oxytocin Receptor, and Vasopressin Gene Promoters in Tobacco Use Disorder during Cessation

INTRODUCTION

Vasopressin (AVP) and oxytocin (OT) exert sex-specific effects on social pair bonding and stress reactions while also influencing craving in substance use disorders. In this regard, intranasal oxytocin (OT) and AVP antagonists present potential treatments for tobacco use disorder (TUD). Since transcription of both hormones is also regulated by gene methylation, we hypothesized sex-specific changes in methylation levels of the AVP, OT, and OT receptor (OXTR) gene during nicotine withdrawal.

METHODS

The study population consisted of 49 smokers (29 males, 20 females) and 51 healthy non-smokers (25 males, 26 females). Blood was drawn at day 1, day 7, and day 14 of smoking cessation. Craving was assessed with the questionnaire on smoking urges (QSU).

RESULTS

Throughout cessation, mean methylation of the OT promoter gene increased in males and decreased in females. OXTR receptor methylation decreased in females, while in males it was significantly lower at day 7. Regarding the AVP promoter, mean methylation increased in males while there were no changes in females. Using mixed linear modeling, CpG position, time point, sex, and the interaction of time point and sex as well as time point, sex, and QSU had a significant fixed effect on OT and AVP gene methylation. The interaction effect suggests that sex, time point, and QSU are interrelated, meaning that, depending on the sex, methylation could be different at different time points and vice versa. There was no significant effect of QSU on mean OXTR methylation.

DISCUSSION

We identified differences at specific CpGs between controls and smokers in OT and AVP and in overall methylation of the AVP gene. Furthermore, we found sex-specific changes in mean methylation levels of the mentioned genes throughout smoking cessation, underlining the relevance of sex in the OT and vasopressin system. This is the first study on epigenetic regulation of the OT promoter in TUD. Our results have implications for research on the utility of the AVP and OT system for treating substance craving. Future studies on both targets need to analyze their effect in the context of sex, social factors, and gene regulation.

No time to lose: the current state of research in rapid-acting psychotherapeutics

The vast majority of treatments for psychiatric and substance use disorders take weeks to work. Notable exceptions to this rule exist, with some treatments such as intravenous ketamine resolving symptoms in minutes to hours. Current research is focused on identifying novel approaches to rapid-acting psychotherapeutics. Promising results from studies of novel classes of drugs and innovative brain stimulation therapies are currently being studied through both clinical and pre-clinical research, as described here. Research focused on understanding neurobiological mechanisms, effective therapeutic context, and implementation approaches are needed to maximize the potential reach of these therapies.

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.

Neural Functions of Hypothalamic Oxytocin and its Regulation

Oxytocin (OT), a nonapeptide, has a variety of functions. Despite extensive studies on OT over past decades, our understanding of its neural functions and their regulation remains incomplete. OT is mainly produced in OT neurons in the supraoptic nucleus (SON), paraventricular nucleus (PVN) and accessory nuclei between the SON and PVN. OT exerts neuromodulatory effects in the brain and spinal cord. While magnocellular OT neurons in the SON and PVN mainly innervate the pituitary and forebrain regions, and parvocellular OT neurons in the PVN innervate brainstem and spinal cord, the two sets of OT neurons have close interactions histologically and functionally. OT expression occurs at early life to promote mental and physical development, while its subsequent decrease in expression in later life stage accompanies aging and diseases. Adaptive changes in this OT system, however, take place under different conditions and upon the maturation of OT release machinery. OT can modulate social recognition and behaviors, learning and memory, emotion, reward, and other higher brain functions. OT also regulates eating and drinking, sleep and wakefulness, nociception and analgesia, sexual behavior, parturition, lactation and other instinctive behaviors. OT regulates the autonomic nervous system, and somatic and specialized senses. Notably, OT can have different modulatory effects on the same function under different conditions. Such divergence may derive from different neural connections, OT receptor gene dimorphism and methylation, and complex interactions with other hormones. In this review, brain functions of OT and their underlying neural mechanisms as well as the perspectives of their clinical usage are presented.

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.

Oxytocin Signaling as a Target to Block Social Defeat-Induced Increases in Drug Abuse Reward

There is huge scientific interest in the neuropeptide oxytocin (OXT) due to its putative capacity to modulate a wide spectrum of physiological and cognitive processes including motivation, learning, emotion, and the stress response. The present review seeks to increase the understanding of the role of OXT in an individual’s vulnerability or resilience with regard to developing a substance use disorder. It places specific attention on the role of social stress as a risk factor of addiction, and explores the hypothesis that OXT constitutes a homeostatic response to stress that buffers against its negative impact. For this purpose, the review summarizes preclinical and clinical literature regarding the effects of OXT in different stages of the addiction cycle. The current literature affirms that a well-functioning oxytocinergic system has protective effects such as the modulation of the initial response to drugs of abuse, the attenuation of the development of dependence, the blunting of drug reinstatement and a general anti-stress effect. However, this system is dysregulated if there is continuous drug use or chronic exposure to stress. In this context, OXT is emerging as a promising pharmacotherapy to restore its natural beneficial effects in the organism and to help rebalance the functions of the addicted brain.

Neural bases of risky decisions involving nicotine vapor versus monetary reward

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• Most studies of addiction with fMRI use only money reward.

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• Little is known about the neural basis of real-time drug use decisions.

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• Subjects gambled for either money or immediate nicotine vape reward in scanner.

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• The neural response to immediate drug reward is different from monetary reward.

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• Money reward has limitations as a proxy for studying addiction.

Substantial effort has gone into neuroimaging studies of neural mechanisms underlying addiction. Human studies of smoking typically either give monetary reward during an fMRI task or else allow subjects to smoke outside the scanner, after the session. This raises a fundamental issue of construct validity, as it is unclear whether the same neural mechanisms process decisions about nicotine that process decisions about money. To address this, we developed a novel MR-compatible nicotine vaping device, such that access to nicotine vapor could be controlled and monitored. We recruited heavy smokers (Money: 45 subjects, 13 females and 32 males; Nicotine: 21 subjects, 4 females and 17 males) to perform a gambling task with nicotine and monetary reward on separate days. We collected BOLD fMRI data while they performed the task inside the scanner and analyzed it using general linear modeling, with inference based on cluster-size correction. This allowed a direct comparison between the neural mechanisms of choosing and receiving immediate drug vs. monetary reward. We found substantial differences in the neural mechanisms that underlie risky choices about money vs. drug reward, including a reversal of the well-known error effects in the medial prefrontal cortex.

Efficacy of Self-Administered Intranasal Oxytocin on Alcohol Use and Craving After Detoxification in Patients With Alcohol Dependence. A Double-Blind Placebo-Controlled Trial

Aims

The aim of this study was to assess the efficacy of self-administered intranasal oxytocin on alcohol dependence after detoxification.

Methods

In a double-blind, randomized, placebo-controlled trial, 38 patients fulfilling the criteria for ICD-10 diagnosis of alcohol dependence received either 8 IU oxytocin or placebo at their own discretion up to thrice daily for 4 weeks, after completing detoxification. Primary outcome was alcohol intake specified as the amount of alcohol consumed, the number of days to relapse into alcohol use and the proportion of subjects relapsing. Secondary outcomes were self-reported symptoms of craving, sleep and mental distress.

Results

There were no significant differences between the oxytocin group and the placebo group in daily alcohol intake in total (mean 1.3 ± 2.9 vs. 2.0 ± 5.0 units; P = 0.63) or on drinking days (mean 8.4 ± 2.7 vs. 7.7 ± 6.0 units; P = 0.76), in the number of days until relapse (P = 0.91) or in the proportion of subjects relapsing (37.5 vs. 41.2%; P = 0.84). Neither were there any statistically significant differences in any other outcomes, except a larger decrease in self-reported nervousness in the oxytocin group (P = 0.022).

Conclusion

The results were inconclusive as to whether intranasal oxytocin reduced the time to relapse, degree of craving or total amount of alcohol consumed after detoxification. However, the oxytocin group had a larger decrease in self-reported nervousness.

The effect of oxytocin, gender, and ovarian hormones on stress reactivity in individuals with cocaine use disorder

RATIONALE

Cocaine use disorder (CUD) is associated with dysregulation of the hypothalamic-pituitary-adrenal axis, which plays a critical role in the human stress response. Men and women with CUD differ in reactivity to social stressors. The hypothalamic neuropeptide oxytocin is involved in anxiolytic and natural reward processes, and has shown therapeutic potential for addictive disorders and stress reduction.

OBJECTIVES

To examine the impact of oxytocin (oxytocin (OXY) vs. placebo (PBO)) and gender (female (F) vs. male (M)) on response to a social stress task in individuals with CUD. To explore whether ovarian hormones moderate this stress response.

METHODS

One hundred twelve adults with CUD were randomized to receive 40 IU intranasal oxytocin (n = 56) or matching placebo (n = 56). Forty minutes after drug administration, participants were exposed to a social stressor. Generalized linear mixed models were used to examine neuroendocrine (cortisol) and subjective (craving, stress) response at pre-stressor, stressor + 0, + 10, + 30, + 60 min.

RESULTS

Gender moderated the effect of oxytocin on neuroendocrine response (p = 0.048); women receiving oxytocin (F + OXY) showed blunted cortisol response compared to the other three groups (F + PBO; M + OXY; M + PBO). There was a main effect of gender on subjective stress response; women reported greater stress following the stressor compared to men (p = 0.016). Oxytocin had no significant effect on craving or stress, and gender did not moderate the effect of oxytocin on either measure. Higher endogenous progesterone was associated with lower craving response in women (p = 0.033).

CONCLUSIONS

Oxytocin may have differential effects in men and women with CUD. Women may be at greater risk for relapse in response to social stressors, but ovarian hormones may attenuate this effect.

Oxytocin treatment for alcoholism: Potential neurocircuitry targets

Oxytocin (OT) has gained considerable interest in recent years as a potential treatment for alcoholism and other substance use disorders. Evidence continues to mount that OT administered either centrally, peripherally or intranasally can decrease ethanol intake in both humans and animal models. The potential mechanisms for the ability of OT to decrease ethanol reward, and importantly, cue- and stress-induced ethanol relapse, are explored by reviewing the specific neuronal circuits involved in mediating these actions and their sensitivity to OT. In addition to dopamine neurons that project from ventral tegmental area (VTA) to nucleus accumbens (NAc) to signal positively reinforcing events, OT receptors (OxTR) are also expressed by dopamine neurons that project from VTA to brain regions that can convey aversive properties of a stimulus. Moreover, OxTR are expressed by non-dopaminergic neurons in the VTA, such as GABA and glutamate neurons, which can both modulate the activity of dopamine VTA neurons locally (in opposite directions) or can project to other brain regions, including the NAc, where it can alter either positive reinforcement or aversion caused by ethanol. The ability of OT to regulate limbic circuitry and the hypothalamic-pituitary-adrenal axis is discussed as a potential mechanism for the ability of OT to inhibit ethanol-induced negative reinforcement. Together, understanding the diversity and complexity of OT regulation of ethanol reward may contribute to more effective use of OT as pharmacotherapy for alcohol use disorder. This article is part of the special issue on Neuropeptides.

Potential for limited reinforcing and abuse-related subjective effects of intranasal oxytocin

BACKGROUND

There has been growing interest in using oxytocin as a pharmacotherapy for psychiatric disorders, including substance use disorder. Limited data exist regarding oxytocin's reinforcing efficacy, which is a necessary consideration for novel pharmacotherapies, especially in substance-using populations.

AIMS

This study aimed to determine the potential reinforcing effects of intranasally administered oxytocin by assessing behavioral economic demand and subjective effects.

METHODS

Healthy adults (n = 23) participated in a double-blind, repeated-measures, laboratory study wherein they received intranasal oxytocin (40 IU) or placebo in a randomized order across two sessions. Participants completed drug purchasing tasks at the conclusion of both sessions. Throughout both sessions, subjective and physiological effects were assessed.

RESULTS

Demand-curve analysis of purchasing tasks revealed greater median purchasing for oxytocin relative to placebo. Physiological and subjective effects did not significantly differ between oxytocin and placebo. However, a nonsignificant trend was observed for moderately greater drug liking for oxytocin relative to placebo. There was a significant, positive correlation between the difference in drug liking (between oxytocin and placebo) and the difference in lowest-price purchasing (between oxytocin and placebo).

CONCLUSIONS

These data suggest the potential for limited reinforcing and abuse-related subjective effects of intranasal oxytocin. Given the small sample, the greater drug liking of oxytocin compared to placebo, and the positive relation between demand and drug liking, it is possible that oxytocin may produce reinforcing effects in some participants. Therefore, additional studies of oxytocin reinforcement are warranted.

The influence of gender and oxytocin on stress reactivity, cigarette craving, and smoking in a randomized, placebo-controlled laboratory relapse paradigm

RATIONALE

Female cigarette smokers tend to show greater cessation failure compared with males. Variables that contribute to the maintenance of smoking, including stress and craving, may differentially impact male and female smokers. Novel pharmacotherapies, such as oxytocin, may attenuate stress reactivity and craving in smokers, but work in this area is limited.

OBJECTIVES

This study assessed the influence of gender and oxytocin on stress reactivity, craving, and smoking in a randomized, placebo-controlled laboratory relapse paradigm.

METHODS

Male and female adult cigarette smokers (ages 18-45) were enrolled (women oversampled 2:1) and completed a laboratory session, in which intranasal oxytocin or placebo was administered followed by a laboratory social stress task. The role of gender and oxytocin were assessed on measures of stress reactivity, cigarette craving, latency to smoke in a resistance task, subjective responses to smoking, and ad-libitum smoking.

RESULTS

Participants (N = 144) had a mean age of 31 were 63% female and 56% White. Following stress induction, female smokers evidenced greater subjective stress than males, though males demonstrated greater neuroendocrine reactivity and smoking intensity than females. No gender differences were demonstrated for craving. Oxytocin did not attenuate any aspect of stress reactivity, craving, smoking, or subjective responses to smoking compared with placebo.

CONCLUSIONS

Gender differences in stress reactivity were shown in the hypothesized direction, but oxytocin appeared to exert little impact on subjective or behavioral metrics. Results highlight the complex relationship between gender, stress, and smoking, as well as the implications for oxytocin as a potential pharmacotherapy for smoking cessation.

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.