A Preliminary Examination of Endogenous Peripheral Oxytocin in a Pilot Randomized Clinical Trial of Oxytocin-Enhanced Psychotherapy for Posttraumatic Stress Disorder

Oxytocin Reduces Sensitized Stress-Induced Alcohol Relapse in a Model of Posttraumatic Stress Disorder and Alcohol Use Disorder Comorbidity

BACKGROUND

There is high comorbidity of posttraumatic stress disorder (PTSD) and alcohol use disorder with few effective treatment options. Animal models of PTSD have shown increases in alcohol drinking, but effects of stress history on subsequent vulnerability to alcohol relapse have not been examined. Here we present a mouse model of PTSD involving chronic multimodal stress exposure that resulted in long-lasting sensitization to stress-induced alcohol relapse, and this sensitized stress response was blocked by oxytocin (OT) administration.

METHODS

Male and female mice trained to self-administer alcohol were exposed to predator odor (TMT) + yohimbine over 5 consecutive days or left undisturbed. After reestablishing stable alcohol responding/intake, mice were tested under extinction conditions, and then all mice were exposed to TMT or context cues previously associated with TMT before a reinstatement test session. Separate studies examined messenger RNA expression of Oxt and Oxtr in hypothalamus following chronic stress exposure. A final study examined the effects of systemic administration of OT on stress-induced alcohol relapse in mice with and without a history of chronic stress experience.

RESULTS

Chronic stress exposure produced long-lasting sensitization to subsequent stress-induced alcohol relapse that also generalized to stress-related context cues and transcriptional changes in hypothalamic OT system. OT injected before the reinstatement test session completely blocked the sensitized stress-induced alcohol relapse effect.

CONCLUSIONS

Collectively, these results provide support for the therapeutic potential of OT, along with highlighting the value of utilizing this model in evaluating other pharmacological interventions for treatment of PTSD/alcohol use disorder comorbidity.

A transdiagnostic meta-analysis of acute augmentations to psychological therapy

At least half of all patients with mental health disorders do not respond adequately to psychological therapy. Acutely enhancing particular biological or psychological processes during psychological therapy may improve treatment outcomes. However, previous studies are confined to specific augmentation approaches, typically assessed within single diagnostic categories. Our objective was to assess to what degree acute augmentations of psychological therapy reduce psychiatric symptoms and estimate effect sizes of augmentation types (for example, brain stimulation or psychedelics). We searched Medline, PsycINFO and Embase for controlled studies published between database inception and 25 May 2022. We conducted a preregistered random-effects meta-analysis (PROSPERO CRD42021236403). We identified 108 studies (N = 5,889). Acute augmentation significantly reduced the severity of mental health problems (Hedges' g = -0.27, 95% CI: [-0.36, -0.18]; P < 0.0001), particularly for the transdiagnostic dimensions 'Fear' and 'Distress'. This result survived a trim-and-fill analysis to account for publication bias. Subgroup analyses revealed that pharmacological, psychological and somatic augmentations were effective, but to varying degrees. Acute augmentation approaches are a promising route to improve outcomes from psychological therapy.

Oxytocin: An Old Hormone, A Novel Psychotropic Drug And Possible Use In Treating Psychiatric Disorders

BACKGROUND

Oxytocin is a nonapeptide synthesized in the paraventricular and supraoptic nuclei of the hypothalamus. Historically, this molecule has been involved as a key factor in the formation of infant attachment, maternal behavior and pair bonding and, more generally, in linking social signals with cognition, behaviors and reward. In the last decades, the whole oxytocin system has gained a growing interest as it was proposed to be implicated in etiopathogenesis of several neurodevelopmental and neuropsychiatric disorders.

METHODS

With the main goal of an in-depth understanding of the oxytocin role in the regulation of different functions and complex behaviors as well as its intriguing implications in different neuropsychiatric disorders, we performed a critical review of the current state of art. We carried out this work through PubMed database up to June 2021 with the search terms: 1) "oxytocin and neuropsychiatric disorders"; 2) "oxytocin and neurodevelopmental disorders"; 3) "oxytocin and anorexia"; 4) "oxytocin and eating disorders"; 5) "oxytocin and obsessive-compulsive disorder"; 6) "oxytocin and schizophrenia"; 7) "oxytocin and depression"; 8) "oxytocin and bipolar disorder"; 9) "oxytocin and psychosis"; 10) "oxytocin and anxiety"; 11) "oxytocin and personality disorder"; 12) "oxytocin and PTSD".

RESULTS

Biological, genetic, and epigenetic studies highlighted quality and quantity modifications in the expression of oxytocin peptide or in oxytocin receptor isoforms. These alterations would seem to be correlated with a higher risk of presenting several neuropsychiatric disorders belonging to different psychopathological spectra. Collaterally, the exogenous oxytocin administration has shown to ameliorate many neuropsychiatric clinical conditions.

CONCLUSION

Finally, we briefly analyzed the potential pharmacological use of oxytocin in patient with severe symptomatic SARS-CoV-2 infection due to its anti-inflammatory, anti-oxidative and immunoregulatory properties.

Associations between oxytocin and vasopressin concentrations, traumatic event exposure and posttraumatic stress disorder symptoms: group comparisons, correlations, and courses during an internet-based cognitive-behavioural treatment

Background: Posttraumatic stress disorder (PTSD) is characterized by impairments in extinction learning and social behaviour, which are targeted by trauma-focused cognitive behavioural treatment (TF-CBT). The biological underpinnings of TF-CBT can be better understood by adding biomarkers to the clinical evaluation of interventions. Due to their involvement in social functioning and fear processing, oxytocin and arginine vasopressin might be informative biomarkers for TF-CBT, but to date, this has never been tested. Objective: To differentiate the impact of traumatic event exposure and PTSD symptoms on blood oxytocin and vasopressin concentrations. Further, to describe courses of PTSD symptoms, oxytocin and vasopressin during an internet-based TF-CBT and explore interactions between these parameters. Method: We compared oxytocin and vasopressin between three groups of active and former male service members of the German Armed Forces (n = 100): PTSD patients (n = 39), deployed healthy controls who experienced a deployment-related traumatic event (n = 33) and non-deployed healthy controls who never experienced a traumatic event (n = 28). PTSD patients underwent a 5-week internet-based TF-CBT. We correlated PTSD symptoms with oxytocin and vasopressin before treatment onset. Further, we analysed courses of PTSD symptoms, oxytocin and vasopressin from pre- to post-treatment and 3 months follow-up, as well as interactions between the three parameters. Results: Oxytocin and vasopressin did not differ between the groups and were unrelated to PTSD symptoms. PTSD symptoms were highly stable over time, whereas the endocrine parameters were not, and they also did not change in mean. Oxytocin and vasopressin were not associated with PTSD symptoms longitudinally. Conclusions: Mainly due to their insufficient intraindividual stability, single measurements of endogenous oxytocin and vasopressin concentrations are not informative biomarkers for TF-CBT. We discuss how the stability of these biomarkers might be increased and how they could be better related to the specific impairments targeted by TF-CBT.

Social withdrawal and gender differences: Clinical phenotypes and biological bases

Evidence from everyday life suggests that differences in social behaviors between males and females exist, both in animal and in humans. These differences can be related to socio-cultural determinants, but also to specialized portions of the brain (the social brain), from the neurotransmitter to the neural network level. The high vulnerability of this system is expressed by the wide range of neuropsychiatric disorders associated with social dysfunctions, particularly social withdrawal. The principal psychiatric disorders with prominent social withdrawal are described, including hikikomori-like syndromes, and anxiety, depressive, autistic, schizophrenic, and personality disorders. It is hypothesized that social withdrawal can be partially independent from other symptoms and likely reflect alterations in the social brain itself, leading to a similar, transdiagnostic social dysfunction, reflecting defects in the social brain across a variety of psychopathological conditions. An overview is provided of gender effects in the biological determinants of social behavior, including: the anatomical structures of the social brain; the dimorphic brain structures, and the modulation of their development by sex steroids; gender differences in "social" neurotransmitters (vasopressin and oxytocin), and in their response to social stress. A better comprehension of gender differences in the phenotypes of social disorders and in the neural bases of social behaviors may provide new insights for timely, focused, innovative, and gender-specific treatments.

Impact of Oxytocin on the neural correlates of fearful face processing in PTSD related to childhood Trauma

Background: Posttraumatic stress disorder (PTSD) related to exposure to abuse and neglect during childhood is associated with particularly severe and persistent deleterious outcomes. Amygdala hyperreactivity has been observed in childhood trauma survivors and implicated in symptoms of PTSD. Objective: The neuropeptide oxytocin holds promise as a potential treatment for PTSD due to its ability to attenuate amygdala response to threat cues. However, the effect of oxytocin on amygdala reactivity in individuals with childhood trauma-related PTSD has not been investigated. Method: We employed a double-blind, randomized, placebo-controlled crossover design to examine the effects of intranasal oxytocin (24 IU) versus placebo on amygdala reactivity to fearful faces among childhood-trauma exposed individuals with PTSD (n = 17) and without PTSD (control group; n = 16). Results: Region-of-interest based amygdala fMRI signal magnitude did not differ by group, drug, or group x drug interaction. Self-report of childhood trauma exposure severity was negatively associated with the oxytocin-related change in left amygdala response in the PTSD group, but not in the control group. Supplementary and exploratory whole-brain analyses conducted separately in each group revealed that left amygdala reactivity to fearful faces was absent on placebo but increased on oxytocin in the control group. The PTSD group showed right amygdala activation to fearful faces in both the oxytocin and placebo conditions, but the left amygdala response observed in the placebo condition was diminished on oxytocin. Conclusions: Findings extend the literature pertaining to the potential for oxytocin to attenuate neural correlates of PTSD to a childhood trauma-related PTSD sample.