Similar effects of intranasal oxytocin administration and acute alcohol consumption on socio-cognitions, emotions and behaviour: Implications for the mechanisms of action

Mitigating the impact of adolescence isolation on the development of social anxiety: A potential role for oxytocin

Exposure to isolation can lead to the development of social anxiety disorder (SAD), which affects 13% of Americans. There are sex differences in the prevalence of anxiety disorders, as women experience higher rates of SAD relative to men. Importantly, isolation experienced during adolescence increases the likelihood of developing SAD in adulthood. Unfortunately, the current treatments for SAD are only effective in 50–65% of patients. As such, it is critical to identify therapeutic targets for the treatment and prevention of SAD, particularly in women. Here, we discuss the links between childhood isolation and adulthood SAD. Next, we examine the preclinical models used to study the impact of isolation on social anxiety-like behaviors in rodents. Increasing evidence from both clinical and pre-clinical studies suggests oxytocin signaling is a potential target to modify social anxiety-like behaviors. We present the evidence that sex hormones influence the oxytocin system. Finally, we highlight future directions for both clinical and pre-clinical studies to further evaluate the efficacy of oxytocin as a treatment for isolation-induced SAD.

Oxytocin ameliorates impaired social behavior in a Chd8 haploinsufficiency mouse model of autism

Background

Autism spectrum disorder (ASD) is characterized by the core symptoms of impaired social interactions. Increasing evidence suggests that ASD has a strong genetic link with mutations in chromodomain helicase DNA binding protein 8 (CHD8), a gene encoding a chromatin remodeler. It has previously been shown that Chd8 haplodeficient male mice manifest ASD-like behavioral characteristics such as anxiety and altered social behavior. Along with that, oxytocin (OT) is one of the main neuropeptides involved in social behavior. Administration of OT has shown improvement of social behavior in genetic animal models of ASD. The present study was undertaken to further explore behavioral abnormalities of Chd8 haplodeficient mice of both sexes, their link with OT, and possible effects of OT administration. First, we performed a battery of behavioral tests on wild-type and Chd8^+/∆SL female and male mice. Next, we measured plasma OT levels and finally studied the effects of intraperitoneal OT injection on observed behavioral deficits.

Results

We showed general anxiety phenotype in Chd8^+/∆SL mice regardless of sex, the depressive phenotype in Chd8^+/∆SL female mice only and bidirectional social deficit in female and male mice. We observed decreased level of OT in Chd^+/∆SL mice, possibly driven by males. Mice injected by OT demonstrated recovery of social behavior, while reduced anxiety was observed only in male mice.

Conclusions

Here, we demonstrated that abnormal social behaviors were observed in both male and female Chd8^+/∆SL mice. The ability of peripheral OT administration to affect such behaviors along with altered plasma OT levels indicated a possible link between Chd8 + /∆SL and OT in the pathogenesis of ASD as well as the possible usefulness of OT as a therapeutic tool for ASD patients with CHD8 mutations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12868-021-00631-6.

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 moderating role of infidelity on the relation between oxytocin and conflict behaviors among substance misusing couples

The neuropeptide oxytocin (OT) may be beneficial to augmenting behavioral therapies for couples given its ability to alleviate stress reactivity and increase pro-social behavior. However, there is growing evidence demonstrating inconsistent effects of OT on social behavior. Infidelity may represent a relational vulnerability that modulates the OT response. The present study hypothesized that actor and partner emotional and physical infidelity would be associated with less adaptive conflict behaviors, and moderate the OT response, such that participants randomized to a OT condition, compared to placebo, who report more infidelity would show less adaptive conflict behaviors. Participants were 30 couples (N = 60) wherein one or both partners engaged in recent hazardous drinking or illicit drug use. Partners completed a 10-min dyadic conflict task in the laboratory, self-administered a single intranasal dose of OT (40 IU) or placebo, and then completed the same 10-min dyadic conflict task following a 45-min wait period. Couple conflict behaviors were observed during the conflict tasks and assessed using a validated coding system. Actor partner interdependence models detected significant interactions between drug condition and physical infidelity, such that among individuals in the OT group, verses individuals in the placebo group, (a) who reported greater physical infidelity had greater distress maintaining attributions and (b) whose partners reported greater physical infidelity had fewer relationship enhancing attributions. Results are consistent with the social salience hypothesis of OT and suggest that physical infidelity appears to serve as a contextual vulnerability that may decreases positive and increase negative behaviors during conflict. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

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.

Neuroethical issues in cognitive enhancement: Modafinil as the example of a workplace drug?

The use of cognitive-enhancing drugs by healthy individuals has been a feature for much of recorded history. Cocaine and amphetamine are modern cases of drugs initially enthusiastically acclaimed for enhancing cognition and mood. Today, an increasing number of healthy people are reported to use cognitive-enhancing drugs, as well as other interventions, such as non-invasive brain stimulation, to maintain or improve work performance. Cognitive-enhancing drugs, such as methylphenidate and modafinil, which were developed as treatments, are increasingly being used by healthy people. Modafinil not only affects ‘cold’ cognition, but also improves ‘hot’ cognition, such as emotion recognition and task-related motivation. The lifestyle use of ‘smart drugs’ raises both safety concerns as well as ethical issues, including coercion and increasing disparity in society. As a society, we need to consider which forms of cognitive enhancement (e.g. pharmacological, exercise, lifelong learning) are acceptable and for which groups under what conditions and by what methods we would wish to improve and flourish.

Design of a randomized controlled trial examining the efficacy of oxytocin to enhance alcohol behavioral couple therapy

Combining pharmacological interventions with evidence-based behavioral interventions may help optimize treatment outcomes for alcohol use disorder (AUD). While several effective behavioral interventions for AUD have been developed, the vast majority target individual patients, despite evidence that behavioral interventions for couples have the ability to outperform individual treatments for AUD. Alcohol Behavioral Couples Therapy (ABCT) is an evidence-based behavioral intervention for couples that has been shown to significantly reduce AUD severity as well as improve relationship functioning. Accumulating evidence suggests that the neuropeptide oxytocin has the ability to reduce alcohol craving and consumption, symptoms of tolerance and withdrawal, and ameliorate neurobiological deficits associated with AUD. Furthermore, oxytocin has demonstrated the ability to increase prosocial behavior and cognition, and restore sensitivity to natural rewards such as interpersonal relationships. No study to date has examined the ability of oxytocin to enhance ABCT. Thus, the primary objective of this Phase II study is to examine the effects of oxytocin versus placebo in combination with ABCT in reducing AUD severity and improving relationship functioning. We also will utilize neuroimaging techniques before and after treatment to investigate the underlying pathophysiology of AUD among couples and identify prognostic indicators of treatment outcome. The findings from this study might provide critical new information to help inform clinical practice and accelerate research on the pharmacological treatment of AUD.

Intranasal Oxytocin Does Not Modulate Responses to Alcohol in Social Drinkers

BACKGROUND

Preclinical and clinical evidence suggest that the neuropeptide oxytocin may be of value in treating alcohol use disorder, by either reducing the rewarding effects of alcohol or reducing negative affect induced by alcohol withdrawal. However, the effect of a single dose of oxytocin on subjective and psychomotor responses to alcohol in social drinkers is not known.

METHODS

This study examined the effect of intranasal oxytocin on subjective, behavioral, and physiological responses to a moderate dose of alcohol (0.8 g/kg) in young adult social drinkers. Participants (N = 35) completed 2 study sessions at which they consumed beverages containing alcohol (ALC; N = 20) or placebo (NoALC; N = 15) in combination with intranasal oxytocin (40 IU with a 20 IU booster) or placebo. They received oxytocin at one session and placebo at the other session (order counterbalanced) 20 minutes before consuming beverages. Subjective mood and drug effects ratings, heart rate and blood pressure, and 4 behavioral tasks (flanker task, digit span, go/no-go, and pursuit rotor) were the primary outcome measures.

RESULTS

ALC produced its expected subjective and behavioral effects; including feeling intoxicated and impaired performance on the digit span and go/no-go tasks. Oxytocin alone had no significant subjective or physiological effects, and it did not affect responses to alcohol on any measure.

CONCLUSIONS

We can conclude that, under these conditions, a single dose of intranasal oxytocin does not alter the effects of acute alcohol in healthy young adult social drinkers. Further research is needed to determine whether oxytocin alters responses to alcohol under different conditions, and to determine its potential as an aid in treatment for substance use disorders.

Effects of Intranasal Oxytocin on Emotion Recognition in Korean Male: A Dose-Response Study

OBJECTIVE

Research has shown that intranasal oxytocin affects social cognition and behavior; however, its effects vary based on social context, individual characteristics and dose. The present study aimed to determine effective dose of oxytocin spray on emotion recognition in healthy Korean males.

METHODS

The study followed a randomized, double-blind, placebo-controlled design. Thirty-seven Korean males underwent two experimental sessions, with one week in between. They received either 32 (n=19) or 40 (n=18) international units (IU) of oxytocin and placebo, and then completed a face emotion recognition task. The effect of oxytocin on emotion recognition was examined using repeated measures analysis of variance (ANOVA) for each dose condition.

RESULTS

The higher dose (40 IU) was found to improve recognition of happy faces, while the lower dose (32 IU) had no effect. There were no statistical differences in age, education, attachment style or empathic ability between the two dose groups.

CONCLUSION

The results suggest that oxytocin increases the ability of Korean males to recognize positive emotion, and this effect is dose-dependent. Additional studies evaluating the effect of higher doses of oxytocin on social cognition will help to determine the optimal dose for Korean populations.

Empathy for Distress in Humans and Rodents

Empathy is traditionally thought to be a unique ability of humans to feel, understand, and share the emotional state of others. However, the notion has been greatly challenged by the emerging discoveries of empathy for pain or distress in rodents. Because empathy is believed to be fundamental to the formation of prosocial, altruistic, and even moral behaviors in social animals and humans, studies associated with decoding the neural circuits and unraveling the underlying molecular and neural mechanisms of empathy for pain or distress in rodents would be very important and encouraging. In this review, the author set out to outline and update the concept of empathy from the evolutionary point of view, and introduce up-to-date advances in the study of empathy and its neural correlates in both humans and rodents. Finally, the author highlights the perspectives and challenges for the further use of rodent models in the study of empathy for pain or distress.

The effects of alcohol on emotion in social drinkers

Understanding why people drink alcohol and in some cases develop drinking problems has long puzzled researchers, clinicians, and patients alike. In the mid-1940s and early 1950s, experimental research began to systematically investigate alcohol's hedonic properties. Presumably, alcohol consumption would prove reinforcing as a consequence of its capacity either to relieve stress or to brighten positive emotional experiences. This article reviews experimental research through the years examining the impact of alcohol on both the relief of negative affect and the enhancement of positive affect. It covers initial accounts that emphasized direct pharmacological effects of ethanol on the central nervous system. These early studies offered surprisingly tepid support for the premise that alcohol improved emotional states. Next, studies conducted in the 1970s are considered. Informed by social learning theory and employing advances derived from experimental psychology, this research sought to better understand the complex effects of alcohol on emotion. Coverage of this work is followed by discussion of current formulations, which integrate biological and behavioral approaches with the study of cognitive, affective, and social processes. These current perspectives provide insight into the particular conditions under which alcohol can boost emotional experiences. Finally, future research directions and clinical implications are considered.

Alcohol acutely enhances decoding of positive emotions and emotional concern for positive stimuli and facilitates the viewing of sexual images

RATIONALE

Social cognition influences social interactions. Alcohol reportedly facilitates social interactions. However, the acute effects of alcohol on social cognition are relatively poorly studied.

METHODS

We investigated the effects of alcoholic or non-alcoholic beer on emotion recognition, empathy, and sexual arousal using the dynamic face emotion recognition task (FERT), Multifaceted Empathy Test (MET), and Sexual Arousal Task (SAT) in a double-blind, random-order, cross-over study in 60 healthy social drinkers. We also assessed subjective effects using visual analog scales (VASs), blood alcohol concentrations, and plasma oxytocin levels.

RESULTS

Alcohol increased VAS ratings of stimulated, happy, talkative, open, and want to be with others. The subjective effects of alcohol were greater in participants with higher trait inhibitedness. Alcohol facilitated the recognition of happy faces on the FERT and enhanced emotional empathy for positive stimuli on the MET, particularly in participants with low trait empathy. Pictures of explicit sexual content were rated as less pleasant than neutral pictures after non-alcoholic beer but not after alcoholic beer. Explicit sexual pictures were rated as more pleasant after alcoholic beer compared with non-alcoholic beer, particularly in women. Alcohol did not alter the levels of circulating oxytocin.

CONCLUSIONS

Alcohol biased emotion recognition toward better decoding of positive emotions and increased emotional concern for positive stimuli. No support was found for a modulatory role of oxytocin. Alcohol also facilitated the viewing of sexual images, consistent with disinhibition, but it did not actually enhance sexual arousal. These effects of alcohol on social cognition likely enhance sociability.

TRIAL REGISTRATION

www.clinicaltrials.gov/ct2/show/NCT02318823.

Oxytocin receptor gene variation rs53576 and alcohol abuse in a longitudinal population representative study

BACKGROUND

Oxytocin is an important regulator of social relationships and has been implicated in development of substance use and addiction. We examined the association of a variance in the oxytocin receptor gene (OXTR rs53576 polymorphism) with alcohol use in a population-representative sample, and potential moderation by social functioning.

METHODS

The analysis was carried out on the older birth cohort of the longitudinal Estonian Children Personality Behaviour and Health Study (ECPBHS), a cohort of initially 15 years old children (original n=593) recalled at ages 18 and 25. In all data collection waves the participants reported the frequency of consuming alcoholic beverages. Psychiatric interview was carried out at age 25 to assess the lifetime prevalence of substance use disorders. Adverse social interactions with teachers, classmates and family members were self-reported at ages 15 and 18. The minor (A) allele frequency was 0.37.

RESULTS

Males homozygous for the A allele (suggested to be associated with less efficient oxytocinergic functioning) were more frequent alcohol consumers at ages 15 and 18 and also more likely to have had alcohol abuse or addiction by age 25 compared to male G allele carriers. Alcohol use was not associated with the OXTR genotype in females. Both male and female AA homozygotes who had reported less favourable relations with their teachers at age 15 more likely had alcohol use disorder.

CONCLUSIONS

OXTR rs53576 polymorphism is associated with alcohol use and prevalence of alcohol use disorders in males, and this may be moderated by inferior interpersonal relationships.

Free love? On the relation between belief in free will, determinism, and passionate love

Is love possible if we are not free? Some philosophers consider that true love is necessarily free, while others think that the nature of love makes it incompatible with a certain type of freedom. Here, we explored the relationship between feelings of passionate love, belief in free will and determinism across three online studies. In Study 1 (N=257), participants who believed strongly in free will (or determinism) expressed stronger passionate love. In Study 2 (N=305), we again found a positive association between belief in free will (or determinism) and passionate love, although the passionate love-determinism relationship seems more conditional. Finally, Study 3 (N=309) confirmed the relationship between belief in free will and passionate love but not between belief in determinism and passionate love. These findings, along with a meta-analysis, suggest that both beliefs in free will and determinism are compatible with passionate love.

Ethanol Increases Mechanical Pain Sensitivity in Rats via Activation of GABAA Receptors in Medial Prefrontal Cortex

Ethanol is widely known for its ability to cause dramatic changes in emotion, social cognition, and behavior following systemic administration in humans. Human neuroimaging studies suggest that alcohol dependence and chronic pain may share common mechanisms through amygdala-medial prefrontal cortex (mPFC) interactions. However, whether acute administration of ethanol in the mPFC can modulate pain perception is unknown. Here we showed that bilateral microinjections of ethanol into the prelimbic and infralimbic areas of the mPFC lowered the bilateral mechanical pain threshold for 48 h without influencing thermal pain sensitivity in adult rats. However, bilateral microinjections of artificial cerebrospinal fluid into the mPFC or bilateral microinjections of ethanol into the dorsolateral PFC (also termed as motor cortex area 1 in Paxinos and Watson's atlas of The Rat Brain. Elsevier Academic Press, Amsterdam, 2005) failed to do so, suggesting regional selectivity of the effects of ethanol. Moreover, bilateral microinjections of ethanol did not change the expression of either pro-apoptotic (caspase-3 and Bax) or anti-apoptotic (Bcl-2) proteins, suggesting that the dose was safe and validating the method used in the current study. To determine whether γ-aminobutyric acid A (GABAA) receptors are involved in mediating the ethanol effects, muscimol, a selective GABAA receptor agonist, or bicuculline, a selective GABAA receptor antagonist, was administered alone or co-administered with ethanol through the same route into the bilateral mPFC. The results showed that muscimol mimicked the effects of ethanol while bicuculline completely reversed the effects of ethanol and muscimol. In conclusion, ethanol increases mechanical pain sensitivity through activation of GABAA receptors in the mPFC of rats.

Sniff and mimic - Intranasal oxytocin increases facial mimicry in a sample of men

The neuropeptide oxytocin (OT) has many potential social benefits. For example, intranasal administration of OT appears to trigger caregiving behavior and to improve the recognition of emotional facial expressions. But the mechanism for these effects is not yet clear. Recent findings relating OT to action imitation and to the visual processing of the eye region of faces point to mimicry as a mechanism through which OT improves processing of emotional expression. To test the hypothesis that increased levels of OT in the brain enhance facial mimicry, 60 healthy male participants were administered, in a double-blind between-subjects design, 24 international units (IUs) of OT or placebo (PLA) through nasal spray. Facial mimicry and emotion judgments were recorded in response to movie clips depicting changing facial expressions. As expected, facial mimicry was increased in the OT group, but effects were strongest for angry infant faces. These findings provide further evidence for the importance of OT in social cognitive skills, and suggest that facial mimicry mediates the effects of OT on improved emotion recognition.