Pharmacologic management of comorbid post-traumatic stress disorder and addictions

Xenon gas as a potential treatment for opioid use disorder, alcohol use disorder, and related disorders

Xenon gas is considered to be a safe anesthetic and imaging agent. Research on its other potentially beneficial effects suggests that xenon may have broad efficacy for treating health disorders. A number of reviews on xenon applications have been published, but none have focused on substance use disorders. Accordingly, we review xenon effects and targets relevant to the treatment of substance use disorders, with a focus on opioid use disorder and alcohol use disorder. We report that xenon inhaled at subsedative concentrations inhibits conditioned memory reconsolidation and opioid withdrawal symptoms. We review work by others reporting on the antidepressant, anxiolytic, and analgesic properties of xenon, which could diminish negative affective states and pain. We discuss research supporting the possibility that xenon could prevent analgesic- or stress-induced opioid tolerance and, by so doing could reduce the risk of developing opioid use disorder. The rapid kinetics, favorable safety and side effect profiles, and multitargeting capability of xenon suggest that it could be used as an ambulatory on-demand treatment to rapidly attenuate maladaptive memory, physical and affective withdrawal symptoms, and pain drivers of substance use disorders when they occur. Xenon may also have human immunodeficiency virus and oncology applications because its effects relevant to substance use disorders could be exploited to target human immunodeficiency virus reservoirs, human immunodeficiency virus protein-induced abnormalities, and cancers. Although xenon is expensive, low concentrations exert beneficial effects, and gas separation, recovery, and recycling advancements will lower xenon costs, increasing the economic feasibility of its therapeutic use. More research is needed to better understand the remarkable repertoire of effects of xenon and its potential therapeutic applications.

Posttraumatic stress disorder and its cross-generational familial relationship with drug use disorder and alcohol use disorder: an extended Swedish adoption study

Objective: Information on how parental risk for posttraumatic stress disorder (PTSD) relates to their children's risk for drug use disorder (DUD) and alcohol use disorder (AUD) is limited. This study is the first to utilize an extended adoption design which can address questions about the degree of, and sources of, cross-generational and cross-disorder transmission of PTSD and substance use disorders.Method: We examined diagnoses using Swedish National registries for parents and their adult offspring (n = 2,194,171, born 1960-1992) from six types of families (intact (1), not lived with biological father (2) or mother (3), step father (4), step mother (5), and adoptive (6)). Parent-child resemblance was assessed by tetrachoric correlation.Results: PTSD and DUD showed an approximately symmetrical cross-generational cross-disorder relationship. Conversely, AUD in parents was more related to the risk for PTSD in offspring compared to the reverse direction. The cross-disorder cross-generation transmission correlations for PTSD to DUD were higher than those for PTSD to AUD. Genetic and rearing correlations for PTSD-DUD were estimated at + .79 (CI: .66, .91) and + .49 (CI: .33, .65), significantly higher than those for PTSD-AUD + .59 (CI: .48, .71) and + .28 (CI: .12, .44).Conclusions: PTSD and the substance use disorders demonstrated cross-transmission, but more so for DUD. PTSD and DUD demonstrated highly correlated genetic effects, and moderately correlated rearing effects. Correlations of genetic and rearing effects between PTSD and AUD were lower than those for PTSD and DUD.

5-HT2C receptors in the nucleus accumbens constrain the rewarding effects of MDMA

MDMA is a promising adjunct to psychotherapy and has well-known abuse liability, although less than other amphetamine analogs. While the reinforcing dopamine (DA)-releasing properties of MDMA are on par with methamphetamine (METH), MDMA is a far more potent serotonin (5-HT) releaser, via the 5-HT transporter (SERT). MDMA-mediated 5-HT release in a major reward center, the nucleus accumbens (NAc), drives prosocial behaviors via 5-HT1BR activation. We hypothesized that this prosocial mechanism contributes to the reduced reinforcing properties of MDMA compared to METH and used a platform of assays to predict the balance of prosocial and abuse-linked effects of (R)-MDMA, a novel entactogen in clinical development. NAc DA release, measured by GRAB-DA photometry in vivo, increased in proportion to MDMA (7.5 and 15 mg/kg, i.p.) and METH (2 mg/kg i.p.)-conditioned place preference (CPP). Using conditional knockouts (cKOs) for DAT and SERT, microdialysis, and photometry, we found that MDMA-released 5-HT limited MDMA-released DA through actions in the NAc, rather than at ventral tegmental area DAergic cell bodies. SERT cKO reduced the MDMA dose required for CPP three-fold. This enhanced MDMA-CPP and increased DA release were replicated by intra-NAc infusion of either a 5-HT reuptake inhibitor (escitalopram) to prevent MDMA interaction with SERT, or a 5-HT2CR antagonist (SB242084), but not by the 5-HT1BR antagonist NAS-181. These data support separate mechanisms for the low abuse potential versus prosocial effect of MDMA. Using this platform of assays, (R)-MDMA is predicted to have prosocial effects and low abuse potential.

Sex differences in acute early life stress-enhanced fear learning in adult rats

Patients diagnosed with posttraumatic stress disorder (PTSD) present with a spectrum of debilitating anxiety symptoms resulting from exposure to trauma. Women are twice as likely to be diagnosed with anxiety and PTSD compared to men; however, the reason for this vulnerability remains unknown. We conducted four experiments where we first demonstrated a female vulnerability to stress-enhanced fear learning (SEFL) with a moderate, acute early life stress (aELS) exposure (4 footshocks in a single session), compared to a more intense aELS exposure (15 footshocks in a single session) where males and females demonstrated comparable SEFL. Next, we demonstrated that this female vulnerability does not result from differences in footshock reactivity or contextual fear conditioning during the aELS exposure. Finally, using gonadectomy or sham surgeries in adult male and female rats, we showed that circulating levels of gonadal steroid hormones at the time of adult fear conditioning do not explain the female vulnerability to SEFL. Additional research is needed to determine whether this vulnerability can be explained by organizational effects of gonadal steroid hormones or differences in sex chromosome gene expression. Doing so is critical for a better understanding of increased female vulnerability to certain psychiatric diseases.

Post-traumatic stress disorder and risky opioid use among persons living with HIV and chronic pain

Persons with HIV (PWH) experience chronic pain and Post-Traumatic Stress Disorder (PTSD) at higher rates than the general population, and more often receive opioid medications to treat chronic pain. A known association exists between PTSD and substance use disorders, but less is known about the relationship between PTSD and risky opioid use among PWH taking prescribed opioid medications. In this observational study of PWH on long-term opioid medications for pain we examined associations between PTSD symptom severity based on the Post Traumatic Stress Disorder Checklist for DSM-5 (PCL-5, response range 0-80) and the following outcomes: 1) risk for opioid misuse (COMM score ≥13); 2) risky alcohol use (AUDIT score ≥8); 3) concurrent benzodiazepine prescription; and 4) morphine equivalent dose. Among 166 patients, 38 (23%) had a PCL-5 score over 38, indicating high PTSD symptom burden. Higher PCL-5 score (per 10 point difference) was associated with increased odds of opioid misuse (aOR 1.55; 95%CI: 1.31-1.83) and risky drinking (aOR: 1.28;1.07-1.52). No significant association was observed between PCL-5 score and benzodiazepine prescriptions or morphine equivalent dose. These findings suggest that when addressing alcohol and opioid use in PWH on long term opioid therapy, attention to PTSD symptoms is especially important given the higher risk for risky alcohol and opioid use among patients with this common comorbid condition.

FKBP5 inhibitors modulate alcohol drinking and trauma-related behaviors in a model of comorbid post-traumatic stress and alcohol use disorder

Post-traumatic stress disorder (PTSD) leads to enhanced alcohol drinking and development of alcohol use disorder (AUD). Identifying shared neural mechanisms might help discover new therapies for PTSD/AUD. Here, we employed a rat model of comorbid PTSD/AUD to evaluate compounds that inhibit FK506-binding protein 51 (FKBP5), a co-chaperone modulator of glucocorticoid receptors implicated in stress-related disorders. Male and female rats received a familiar avoidance-based shock stress followed by voluntary alcohol drinking. We then assessed trauma-related behaviors through sleep bout cycles, hyperarousal, fear overgeneralization, and irritability. To evaluate the role of stress and alcohol history on the sensitivity to FKBP5 inhibitors, in two separate studies, we administered two FKBP5 inhibitors, benztropine (Study 1) or SAFit2 (Study 2). FKBP5 inhibitors were administered on the last alcohol drinking session and prior to each trauma-related behavioral assessment. We also measured plasma corticosterone to assess the actions of FKBP5 inhibitors after familiar shock stress and alcohol drinking. Benztropine reduced alcohol preference in stressed males and females, while aggressive bouts were reduced in benztropine-treated stressed females. During hyperarousal, benztropine reduced several startle response outcomes across stressed males and females. Corticosterone was reduced in benztropine-treated stressed males. The selective FKBP5 inhibitor, SAFit2, reduced alcohol drinking in stressed males but not females, with no differences in irritability. Importantly, SAFit2 decreased fear overgeneralization in stressed males and females. SAFit2 also reduced corticosterone across stressed males and females. Neither FKBP5 inhibitor changed sleep bout structure. These findings indicate that FKBP5 inhibitors modulate stress-related alcohol drinking and partially modulate trauma-related behaviors. This work supports the hypothesis that targeting FKBP5 may alleviate PTSD/AUD comorbidity.

Development and feasibility testing of an integrated PTSD and adherence intervention cognitive processing therapy-life steps (CPT-L) to improve HIV outcomes: Trial protocol

Despite high rates of Post-Traumatic Stress Disorder (PTSD) in persons living with HIV (PLWH) and poor HIV-related health outcomes associated with PTSD, an effective evidence-based treatment for PTSD symptoms in PLWH does not exist. Negative reinforcement conceptual models posit that avoidant behavior (hallmark symptom of PTSD) demonstrated by PLWH with co-occurring PTSD can contribute to poor antiretroviral therapy (ART) adherence. However, research evaluating the impact of evidence-based treatment for PTSD among HIV infected populations on HIV outcomes is scarce. The Cognitive Processing Therapy (CPT) protocol is an evidence-based PTSD treatment that may address internalized stigma with targeted modifications and improve ART adherence and subsequent viral suppression through reduction of avoidant coping. This study will be the first pilot open-label randomized control trial (RCT) to test feasibility of an integrated evidence-based PTSD treatment (CPT) with an adherence intervention (Lifesteps) delivered in a Ryan White clinic to improve PTSD symptoms, adherence to ART, and retention in HIV care. Primary aims are to (1) conduct theater testing of the CPT and Lifesteps research protocol and evaluate acceptability (n = 12) and (2) deliver a modified CPT protocol (CPT-Lifesteps, or CPT-L) in 60 PLWH/PTSD exploring impact of CPT-L on PTSD symptoms and HIV outcomes compared to a Lifesteps + Standard of Care condition. This innovative research extends PTSD treatment approaches as a paradigm to reduce barriers to ART adherence. Findings of this innovative study are significant because they support the Undetectable = Untransmittable (U[bond, double bond]U) campaign and can help prevent the transmission of HIV infection through increased viral suppression.

The integrated treatment of eating disorders, posttraumatic stress disorder, and psychiatric comorbidity: a commentary on the evolution of principles and guidelines

Psychiatric comorbidity is the norm in the assessment and treatment of eating disorders (EDs), and traumatic events and lifetime PTSD are often major drivers of these challenging complexities. Given that trauma, PTSD, and psychiatric comorbidity significantly influence ED outcomes, it is imperative that these problems be appropriately addressed in ED practice guidelines. The presence of associated psychiatric comorbidity is noted in some but not all sets of existing guidelines, but they mostly do little to address the problem other than referring to independent guidelines for other disorders. This disconnect perpetuates a "silo effect," in which each set of guidelines do not address the complexity of the other comorbidities. Although there are several published practice guidelines for the treatment of EDs, and likewise, there are several published practice guidelines for the treatment of PTSD, none of them specifically address ED + PTSD. The result is a lack of integration between ED and PTSD treatment providers, which often leads to fragmented, incomplete, uncoordinated and ineffective care of severely ill patients with ED + PTSD. This situation can inadvertently promote chronicity and multimorbidity and may be particularly relevant for patients treated in higher levels of care, where prevalence rates of concurrent PTSD reach as high as 50% with many more having subthreshold PTSD. Although there has been some progress in the recognition and treatment of ED + PTSD, recommendations for treating this common comorbidity remain undeveloped, particularly when there are other co-occurring psychiatric disorders, such as mood, anxiety, dissociative, substance use, impulse control, obsessive-compulsive, attention-deficit hyperactivity, and personality disorders, all of which may also be trauma-related. In this commentary, guidelines for assessing and treating patients with ED + PTSD and related comorbidity are critically reviewed. An integrated set of principles used in treatment planning of PTSD and trauma-related disorders is recommended in the context of intensive ED therapy. These principles and strategies are borrowed from several relevant evidence-based approaches. Evidence suggests that continuing with traditional single-disorder focused, sequential treatment models that do not prioritize integrated, trauma-focused treatment approaches are short-sighted and often inadvertently perpetuate this dangerous multimorbidity. Future ED practice guidelines would do well to address concurrent illness in more depth.

Chemogenetic inhibition of a monosynaptic projection from the basolateral amygdala to the ventral hippocampus selectively reduces appetitive, but not consummatory, alcohol drinking-related behaviours

Alcohol use disorder (AUD) and anxiety/stressor disorders frequently co-occur and this dual diagnosis represents a major health and economic problem worldwide. The basolateral amygdala (BLA) is a key brain region that is known to contribute to the aetiology of both disorders. Although many studies have implicated BLA hyperexcitability in the pathogenesis of AUD and comorbid conditions, relatively little is known about the specific efferent projections from this brain region that contribute to these disorders. Recent optogenetic studies have shown that the BLA sends a strong monosynaptic excitatory projection to the ventral hippocampus (vHC) and that this circuit modulates anxiety- and fear-related behaviours. However, it is not known if this pathway influences alcohol drinking-related behaviours. Here, we employed a rodent operant self-administration regimen that procedurally separates appetitive (e.g. seeking) and consummatory (e.g., drinking) behaviours, chemogenetics and brain region-specific microinjections, to determine if BLA-vHC circuitry influences alcohol and sucrose drinking-related measures. We first confirmed prior optogenetic findings that silencing this circuit reduced anxiety-like behaviours on the elevated plus maze. We then demonstrated that inhibiting the BLA-vHC pathway significantly reduced appetitive drinking-related behaviours for both alcohol and sucrose while having no effect on consummatory measures. Taken together, these findings provide the first indication that the BLA-vHC circuit may regulate appetitive reward seeking directed at alcohol and natural rewards and add to a growing body of evidence suggesting that dysregulation of this pathway may contribute to the pathophysiology of AUD and anxiety/stressor-related disorders.

Additive Effects of Stress and Alcohol Exposure on Accelerated Epigenetic Aging in Alcohol Use Disorder

BACKGROUND

Stress contributes to premature aging and susceptibility to alcohol use disorder (AUD), and AUD itself is a factor in premature aging; however, the interrelationships of stress, AUD, and premature aging are poorly understood.

METHODS

We constructed a composite score of stress from 13 stress-related outcomes in a discovery cohort of 317 individuals with AUD and control subjects. We then developed a novel methylation score of stress (MS stress) as a proxy of composite score of stress comprising 211 CpGs selected using a penalized regression model. The effects of MS stress on health outcomes and epigenetic aging were assessed in a sample of 615 patients with AUD and control subjects using epigenetic clocks and DNA methylation-based telomere length. Statistical analysis with an additive model using MS stress and a MS for alcohol consumption (MS alcohol) was conducted. Results were replicated in 2 independent cohorts (Generation Scotland, N = 7028 and the Grady Trauma Project, N = 795).

RESULTS

Composite score of stress and MS stress were strongly associated with heavy alcohol consumption, trauma experience, epigenetic age acceleration (EAA), and shortened DNA methylation-based telomere length in AUD. Together, MS stress and MS alcohol additively showed strong stepwise increases in EAA. Replication analyses showed robust association between MS stress and EAA in the Generation Scotland and Grady Trauma Project cohorts.

CONCLUSIONS

A methylation-derived score tracking stress exposure is associated with various stress-related phenotypes and EAA. Stress and alcohol have additive effects on aging, offering new insights into the pathophysiology of premature aging in AUD and, potentially, other aspects of gene dysregulation in this disorder.

A statistical genetic investigation of psychiatric resilience

Background: Although trauma exposure (TE) is a transdiagnostic risk factor for many psychiatric disorders, not everyone who experiences TE develops a psychiatric disorder. Resilience may explain this heterogeneity; thus, it is critical to understand the etiologic underpinnings of resilience.Objective: The present study sought to examine the genetic underpinnings of psychiatric resilience using genome-wide association studies (GWAS), genome-wide complex trait analysis (GCTA), and polygenic risk score (PRS) analyses.Method: Participants were 6,634 trauma exposed college students attending a diverse, public university in the Mid Atlantic. GWAS and GCTA analyses were conducted, and using GWAS summary statistics from large genetic consortia, PRS analyses examined the shared genetic risk between resilience and various phenotypes.Results: Results demonstrate that nine single-nucleotide polymorphisms (SNPs) met the suggestive of significance threshold, heritability estimates for resilience were non-significant, and that there is genetic overlap between resilience and AD, as well as resilience and PTSD.Conclusion: Mixed findings from the present study suggest additional research to elucidate the etiological underpinnings of resilience, ideally with larger samples less biased by variables such as heterogeneity (i.e. clinical vs. population based) and population stratification. Genetic investigations of resilience have the potential to elucidate the molecular bases of stress-related psychopathology, suggesting new avenues for prevention and intervention efforts.

Comorbid alcohol use and post-traumatic stress disorders: Pharmacotherapy with aldehyde dehydrogenase 2 inhibitors versus current agents

The increased risk of alcohol use disorder (AUD) in individuals with post-traumatic stress disorder (PTSD) is well-documented. Compared to individuals with PTSD or AUD alone, those with co-existing PTSD and AUD exhibit greater symptom severity, poorer quality of life, and poorer treatment outcomes. Although the treatment of comorbid AUD is vital for the effective management of PTSD, there is a lack of evidence on how to best treat comorbid PTSD and AUD, and currently, there are no FDA-approved treatments for the PTSD-AUD comorbidity. The objective of this manuscript is to review the evidence of a promising target for treating the AUD-PTSD comorbidity. First, we summarize the epidemiological evidence and review the completed clinical studies that have tested pharmacotherapeutic approaches for co-existing AUD and PTSD. Next, we summarize the shared pathological factors between AUD and PTSD. We conclude by providing a rationale for selectively inhibiting aldehyde dehydrogenase-2 as a potential target to treat comorbid AUD in persons with PTSD.

Trust in Hospital Physicians Among Patients With Substance Use Disorder Referred to an Addiction Consult Service: A Mixed-methods Study

BACKGROUND

Trust is essential in patient-physician relationships. Hospitalized patients with substance use disorders (SUDs) often experience stigma and trauma in the hospital, which can impede trust. Little research has explored the role of hospital-based addictions care in creating trusting relationships with patients with SUDs. This study describes how trust in physicians changed among hospitalized people with SUDs who were seen by an interprofessional addiction medicine service.

METHODS

We analyzed data from hospitalized patients with SUD seen by an addiction consult service from 2015 to 2018. Participants completed surveys at baseline and 30 to 90 days after hospital discharge. Follow-up assessments included open-ended questions exploring participant experiences with hospitalization and the addiction consult service. We measured provider trust using the Wake Forest Trust scale. We modeled trust trajectories using discrete mixture modeling, and sampled qualitative interviews from those trust trajectories.

RESULTS

Of 328 participants with SUD who had prior hospitalizations but had not previously been seen by an addiction consult service, 196 (59.8%) had both baseline and follow-up trust scores. We identified 3 groups of patients: Persistent-Low Trust, Increasing Trust, and Persistent-High Trust and 4 qualitative themes around in-hospital trust: humanizing care, demonstrating addiction expertise, reliability, and granting agency.

CONCLUSIONS

Most participants retained or increased to high trust levels after hospitalization with an addiction consult service. Addiction consult services can create environments where healthcare providers build trust with, and humanize care for, hospitalized patients with SUD, and can also mitigate power struggles that hospitalized patients with SUD frequently experience.

The iatrogenic opioid crisis: An example of 'institutional corruption of pharmaceuticals'?

RATIONALE

Prescribed opioids are major contributors to the international public health opioid crisis. Such widespread iatrogenic harms usually result from collective decision failures of healthcare organizations rather than solely of individual organizations or professionals. Findings from a system-wide safety analysis of the iatrogenic opioid crisis that includes roles of pertinent healthcare organizations may help avoid or mitigate similar future iatrogenic consequences. In this retrospective exploratory study, we report such an analysis.

METHODS

The study population encompassed the entire age spectrum and included those in whom opioids prescribed for chronic pain (unrelated to malignancy) were associated with death or morbidity. Root cause analysis, incorporating recent suggestions for improvement, was used to identify possible contributory factors from the literature. Based on their mandated roles and potential influences to prevent or mitigate the iatrogenic crisis, relevant organizations were grouped and stratified from most to least influential.

RESULTS

The analysis identified a chain of multiple interrelated causal factors within and between organizations. The most influential organizations were pharmaceutical, political, and drug regulatory; next: experts and their related societies, and publications. Less influential: accreditation, professional licensing and regulatory, academic and healthcare funding bodies. Collectively, their views and decisions influenced prescribing practices of frontline healthcare professionals and advocacy groups. Financial associations between pharmaceutical and most other organizations/groups were common. Ultimately, patients were adversely affected. There was a complex association with psychosocial variables.

LIMITATIONS

The analysis suggests associations not causality.

CONCLUSION

The iatrogenic crisis has multiple intricately linked roots. The major catalyst: pervasive pharma-linked financial conflicts of interest (CoIs) involving most other healthcare organizations. These extensive financial CoIs were likely triggers for a cascade of erroneous decisions and actions that adversely affected patients. The actions and decisions of pharma ranged from unethical to illegal. The iatrogenic opioid crisis may exemplify 'institutional corruption of pharmaceuticals'.

Endocannabinoid System as Therapeutic Target of PTSD: A Systematic Review

Post-Traumatic Stress Disorder (PTSD) is a complex disorder involving dysregulation of stress-related hormones and neurotransmitter systems. Research focused on the endocannabinoid system (eCBS) for anxiety and stress regulation, cognitive and emotional responses modulation and aversive memories extinction, leading to the hypothesis that it could represent a possible alternative treatment target for PTSD. In this systematic review, we summarize evidence about the efficacy and safety of medicinal cannabidiol (CBD), Δ⁹-tetrahydrocannabinol (Δ⁹-THC), and nabilone in PTSD treatment. The PRISMA statement guidelines were followed. A systematic literature search was conducted in MEDLINE/PubMed, Scopus and Web of Science by two independent researchers, who also performed data extraction and quality assessment. Among the initial 495 papers, 234 were screened for eligibility and 10 were included. Studies suggested that different medicinal cannabinoids at distinct doses and formulations could represent promising treatment strategies for the improvement of overall PTSD symptomatology as well as specific symptom domains (e.g., sleep disorders, arousal disturbances, suicidal thoughts), also influencing quality of life, pain and social impact. Although there is a robust rationale for treatment with drugs that target the eCBS and the results are promising, further studies are needed to investigate the safety and efficacy profile of their prolonged use.

The synthetically produced predator odor 2,5-dihydro-2,4,5-trimethylthiazoline increases alcohol self-administration and alters basolateral amygdala response to alcohol in rats

Post-traumatic stress disorder (PTSD) is a psychiatric illness that can increase the risk for developing an alcohol use disorder (AUD). While clinical data has been useful in identifying similarities in the neurobiological bases of these disorders, preclinical models are essential for understanding the mechanism(s) by which stressors increase the risk for escalated alcohol consumption. The purpose of these studies was to examine if exposure of male Long-Evans rats to the synthetically derived predator odor 2,5-dihydro-2,4,5-trimethylthiazoline (TMT; a component of fox feces) would increase sweetened alcohol self-administration, potentially by facilitating transfer of salience towards cues, and alter neuronal response to alcohol as measured by the immediate early gene c-Fos. In experiment 1, rats exposed to repeated (4×) TMT showed reductions in port entries in Pavlovian conditioned approach and increases in sweetened alcohol self-administration. In experiment 2, rats exposed to repeated TMT showed blunted basolateral amygdala c-Fos response to alcohol. In experiment 3, rats exposed to single, but not repeated TMT, showed increases in sweetened alcohol self-administration, and no change in anxiety-like behavior or hyperarousal. In experiment 4, rats continued to show a significant corticosterone response to TMT after repeated exposures. In summary, exposure of male rats to TMT can cause escalations in sweetened alcohol self-administration and reduction in BLA response to alcohol. These studies outline and utilize a novel preclinical model that can be used to further neurobiological understanding of the emergence of escalated alcohol consumption following stress exposure.

The neural, behavioral, and epidemiological underpinnings of comorbid alcohol use disorder and post-traumatic stress disorder

Alcohol use disorder (AUD) and (PTSD) frequently co-occur and individuals suffering from this dual diagnosis often exhibit increased symptom severity and poorer treatment outcomes than those with only one of these diseases. Although there have been significant advances in our understanding of the neurobiological mechanisms underlying each of these disorders, the neural underpinnings of the comorbid condition remain poorly understood. This chapter summarizes recent epidemiological findings on comorbid AUD and PTSD, with a focus on vulnerable populations, the temporal relationship between these disorders, and the clinical consequences associated with the dual diagnosis. We then review animal models of the comorbid condition and emerging human and non-human animal research that is beginning to identify maladaptive neural changes common to both disorders, primarily involving functional changes in brain reward and stress networks. We end by proposing a neural framework, based on the emerging field of affective valence encoding, that may better explain the epidemiological and neural findings on AUD and PTSD.

Additive influences of acute early life stress and sex on vulnerability for aversion-resistant alcohol drinking

Acute early life stress (ELS) alters stress system functioning in adulthood and increases susceptibility to posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD). The current study assessed the effects of acute, infant ELS on alcohol drinking, including aversion-resistant drinking, in male and female Long Evans rats. Acute ELS was induced using a stress-enhanced fear learning (SEFL) protocol that consisted of 15 footshocks delivered on postnatal day (PND) 17. Alcohol drinking during adolescence and adulthood was measured with a two-bottle choice intermittent alcohol access paradigm. Aversion-resistant drinking was assessed in adulthood by adding quinine (0.01, 0.1, and 1.0 g/L) to the alcohol bottle after 5 to 6 weeks and 11 to 12 weeks of drinking. ELS had minimal influences on adolescent and adult alcohol consumption and preference. However, ELS, sex, and alcohol exposure history all influenced aversion-resistant alcohol drinking in an additive fashion. Higher concentrations of quinine were tolerated in females, ELS-exposed rats, and after 11 to 12 weeks of drinking. Tests of quinine sensitivity in a separate cohort of animals found that rats can detect concentrations of quinine as low as 0.001 g/L in water and that quinine sensitivity is not influenced by sex or ELS exposure. These results agree with reports of sex differences in aversion-resistant drinking and are the first to demonstrate an influence of ELS on this behavior. Our results also suggest that a single traumatic stress exposure in infancy may be a promising model of comorbid PTSD and AUD and useful in studying the interactions between ELS, sex, and alcohol dependence.

A Systematic Review of the Self-Medication Hypothesis in the Context of Posttraumatic Stress Disorder and Comorbid Problematic Alcohol Use

Posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) commonly co-occur and are associated with many negative public health outcomes. There are several etiological models that explain the overlap between PTSD and AUD, including shared genetic risk and phenotypic causality, but the predominant model of etiologic association is the drinking-to-cope self-medication model. Although the self-medication model is conceptually appealing and has been widely accepted within the literature examining alcohol use and anxiety (e.g., PTSD) phenotypes, the findings are inconsistent and there is a lack of rigorous empirical evidence in support of this model. This review, which was, to our knowledge, the first systematic review of the self-medication model in relation to PTSD to date, aimed to synthesize the current literature on the association between PTSD and problematic alcohol use within the context of the self-medication model. In total, 24 studies met the inclusion criteria for the review and assessed the self-medication hypothesis using a variety of measurement instruments and data analytic approaches, such as mediation, moderation, and regression. Overall, the included studies provide evidence for the self-medication hypothesis but are limited in rigor due to methodological limitations. These limitations, which include issues with the operationalization (or lack thereof) of trauma-related drinking to cope, are discussed, and directions for future research are presented.

Early Adolescent Binge Drinking Increases Risk of Psychopathology in Post-9/11 Veterans and Mild Traumatic Brain Injury Exacerbates Symptom Severity

Aims

To demonstrate that early adolescent binge drinking (BD) increases the risk for and/or severity of psychopathology in post-9/11 Veterans and determine if mild traumatic brain injury (mTBI) modifies risk.

Methods

Post-9/11 Veterans (n = 375) were classified into two groups: 57 Veterans with a history of early adolescent BD (E-BD; age of onset <15) and 318 who did not BD until age 15 or older (late-BD or L-BD; age of onset ≥15). History of military mTBI and mental health disorders were also assessed following military service.

Results

Logistic regression and analysis of variance (ANOVA) analyses revealed that the E-BD’s had significantly higher prevalence of alcohol use disorders (AUDs) and more severe symptoms of AUD, substance use disorder (SUD), depression and stress. Two-way ANOVAs showed that history of military mTBI was differentially associated with posttraumatic stress disorder (PTSD) incidence and severity among Veterans who had engaged in early adolescent BD. Specifically, Veterans with a history of both early adolescent BD and military mTBI were at greater risk for a PTSD diagnosis and had more severe symptoms of PTSD than those with only a history of adolescent BD. The greater PTSD symptom severity in the comorbid group was driven by hyperarousal symptoms.

Conclusions

A history of BD during early adolescence is prevalent among Veterans and is related to higher risk for AUD and more severe AUD, SUD, mood and stress symptoms later in life. Veterans with early BD and military mTBI showed greater incidence and severity of PTSD, indicating that mTBI, a common comorbidity among post-9/11 Veterans, exacerbates risk.

Shared molecular genetic risk of alcohol dependence and posttraumatic stress disorder (PTSD)

Alcohol use disorder (AUD) and posttraumatic stress disorder (PTSD) frequently co-occur, highlighting the importance of understanding the etiology of these comorbid conditions. Although AUD and PTSD are moderately heritable with modest overlap in genetic risk as estimated from family studies, there has been a paucity of work using molecular genetic data to estimate shared genetic effects on these conditions. This study used large-scale genomewide molecular data to examine shared genetic risk for AUD, specifically alcohol dependence (AD), and PTSD through cross-trait linkage disequilibrium (LD) score regression (LDSC; also known as LDSR). Summary statistics came from the Psychiatric Genomics Consortium (PGC) PTSD Workgroup Freeze 2 European ancestry (EA) participants (N = 174,659) and AD summary statistics in EA participants (N = 38,686) came from the PGC Substance Use Disorders (SUD) Workgroup. We performed LDSC to estimate genetic correlation between AD and PTSD using HapMap3 variants and LD scores from the 1000 Genomes project. A moderate, significant correlation was observed between AD and PTSD (rg = .35, p = .02), with sex differences identified through stratified analyses. Our results are the first to demonstrate evidence of a shared molecular genetic etiology for AD and PTSD. Further research is needed to better understand possible sex differences in shared heritability and extend these results to additional populations. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Bidirectional Control of Alcohol-drinking Behaviors Through Locus Coeruleus Optoactivation

The relationship between stress and alcohol-drinking behaviors has been intensively explored; however, neuronal substrates and neurotransmitter dynamics responsible for a causal link between these conditions are still unclear. Here, we optogenetically manipulated locus coeruleus (LC) norepinephrine (NE) activity by applying distinct stimulation protocols in order to explore how phasic and tonic NE release dynamics control alcohol-drinking behaviors. Our results clearly demonstrate contrasting behavioral consequences of LC-NE circuitry activation during low and high frequency stimulation. Specifically, applying tonic stimulation during a standard operant drinking session resulted in increased intake, while phasic stimulation decreased this measure. Furthermore, stimulation during extinction probe trials, when the lever press response was not reinforced, did not significantly alter alcohol-seeking behavior if a tonic pattern was applied. However, phasic stimulation substantially suppressed the number of lever presses, indicating decreased alcohol seeking under the same experimental condition. Given the well-established correlative link between stress and increased alcohol consumption, here we provide the first evidence that tonic LC-NE activity plays a causal role in stress-associated increases in drinking.

Trauma-related drinking to cope: A novel approach to the self-medication model

Multiple etiological models have been proposed to explain posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) comorbidity, but the predominant model to date is the "drinking to cope" self-medication model. Despite its popularity, the self-medication model lacks rigorous empirical support related to inconsistencies and methodological limitations, particularly the failure to operationalize drinking to cope with trauma symptoms specifically. The present study sought to measure trauma-related drinking to cope (TRD) in order to provide a more specific test of the self-medication model among a representative sample of 1,896 undergraduates with a history of trauma exposure and alcohol use. Using a model-building approach in Mplus, a correlated multiple mediator model tested the association between PTSD symptoms and alcohol use problems (AUPs) through TRD and more generalized drinking to cope motives (as assessed by the coping subscale of the Drinking Motives Questionnaire; DMQ-Cope) as moderated by sex. Results indicated that, while accounting for the effects of generalized drinking to cope motives, TRD partially mediated the relation between PTSD symptoms and AUPs and that this relationship was stronger for males than for females. With the exception of moderation by sex, results were substantiated using longitudinal data. Findings were consistent with the self-medication model, suggesting that TRD motives may serve as a mechanism through which PTSD symptoms influence AUPs. TRD may serve as a more specific screening tool for AUP risk among individuals endorsing PTSD symptoms compared with the commonly used DMQ-Cope. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Associations between Medication Assisted Therapy Services Delivery and Mortality in a National Cohort of Veterans with Posttraumatic Stress Disorder and Opioid Use Disorder

Objective: Opioid use disorder (OUD) is a notable concern in the United States (US) and strongly associated with mortality. There is a high prevalence of OUD in patients with posttraumatic stress disorder (PTSD) and the mortality associated with OUD may be exacerbated in patients with PTSD. Medication-assisted treatment (MAT) for OUD has become standard of care for OUD and has been shown to reduce mortality. However, there has been little study of MAT and mortality in patients with PTSD and OUD. Methods: We conducted a retrospective cohort study in U.S. veterans who had newly engaged in PTSD treatment, were diagnosed with OUD and were provided MAT for at least one day between 2004 and 2013. We assessed mortality for one year following the index diagnosis date. We calculated all-cause mortality as well as death by external cause, overdose plus suicide, overdose, and suicide rates per 100,000. We used hazard ratios (HR) and 95% confidence intervals (CI) to compare death rates between patients with high versus low adherence to MAT. We evaluated the impact of high versus low exposure to general substance abuse care. We considered a confidence interval that did not cross one to be significant. Results: A total of 5,901 patients met inclusion criteria. Most patients were men and the average age was 43.3 years (SD = 13.8). The all-cause mortality rate was 1,370 per 100,000 patients. High adherence to MAT resulted in a non-significant, decreased risk for death due to all-cause (HR = 0.73, 95% CI [0.47, 1.13]), external cause (HR = 0.71, 95% CI [0.38, 1.35]), and overdose or suicide (HR = 0.66, 95% CI [0.33, 1.35]). Patients with high exposure (≥ 60 days) to general substance abuse care were significantly less likely to die due to external cause (HR = 0.39, 95% CI [0.18, 0.85]) and overdose or suicide (HR = 0.31, 95% CI [0.12, 0.77]). Conclusions: In patients with PTSD and OUD, improved adherence to MAT and greater exposure to general substance abuse care may result in lower mortality. Studies with longer follow-up and larger sample sizes to assess the impact of MAT on suicide are needed to confirm our findings.

Chronic repeated predatory stress induces resistance to quinine adulteration of ethanol in male mice

BACKGROUND

Trauma related psychiatric disorders, such as posttraumatic stress disorder (PTSD), and alcohol use disorder (AUD) are highly comorbid illnesses that separately present an opposing, sex-specific pattern, with increased prevalence of PTSD in females and increased prevalence of AUD diagnoses in males. Likewise, PTSD is a risk factor in the development of AUD, with conflicting data on the impact of sex in the comorbid development of both disorders. Because the likelihood of experiencing more than one traumatic event is high, we aim to utilize chronic repeated predatory stress (CRPS) to query the extent to which sex interacts with CRPS to influence alcohol consumption, or cessation of consumption.

METHODS

Male (n = 16) and female (n = 15) C57BL/6 J mice underwent CRPS or daily handling for two weeks during adolescence (P35-P49) and two weeks during adulthood (P65-P79). Following the conclusion of two rounds of repeated stress, behavior was assessed in the open field. Mice subsequently underwent a two-bottle choice intermittent ethanol access (IEA) assessment (P90-131) with the options of 20 % ethanol or water. After establishing drinking behavior, increasing concentrations of quinine were added to the ethanol to assess the drinking response to adulteration of the alcohol.

RESULTS

CRPS increased fecal corticosterone concentrations and anxiety-like behaviors in the open field in both male and female mice as compared to control mice that had not been exposed to CRPS. Consistent with previous reports, we observed a sex difference in alcohol consumption such that females consumed more ethanol per gram of body mass than males. In addition, CRPS reduced alcohol aversion in male mice such that higher concentrations of quinine were necessary to reduce alcohol intake as compared to control mice. CRPS did not alter alcohol-related behaviors in female mice.

CONCLUSION

Collectively, we demonstrate that repeated CRPS can induce anxiety-like behavior in both sexes but selectively influences the response to ethanol adulteration in males.

The predator odor avoidance model of post-traumatic stress disorder in rats

Individuals with post-traumatic stress disorder avoid trauma-related stimuli and exhibit blunted hypothalamic-pituitary-adrenal axis response at the time of trauma. Our laboratory uses predator odor (i.e. bobcat urine) stress to divide adult Wistar rats into groups that exhibit high (avoiders) or low (nonavoiders) avoidance of a predator odor-paired context, modeling the fact that not all humans exposed to traumatic events develop psychiatric conditions. Male avoiders exhibit lower body weight gain after stress, as well as extinction-resistant avoidance that persists after a second stress exposure. These animals also show attenuated hypothalamic-pituitary-adrenal axis response to predator odor that predicts subsequent avoidance of the odor-paired context. Avoiders exhibit unique brain activation profiles relative to nonavoiders and controls (as measured by Fos immunoreactivity), and higher corticotropin-releasing factor levels in multiple brain regions. Furthermore, avoider rats exhibit escalated and compulsive-like alcohol self-administration after traumatic stress. Here, we review the predator odor avoidance model of post-traumatic stress disorder and its utility for tracking behavior and measuring biological outcomes predicted by avoidance. The major strengths of this model are (i) etiological validity with exposure to a single intense stressor, (ii) established approach distinguishing individual differences in stress reactivity, and (iii) robust behavioral and biological phenotypes during and after trauma.

Chronic pain, posttraumatic stress disorder, and opioid intake: A systematic review

BACKGROUND

The literature suggests that there is a high degree of co-occurrence between chronic pain and posttraumatic stress disorder (PTSD). An association has been found between PTSD and substance abuse. PTSD is a severe disorder that should be taken into account when opioids are prescribed. It has been found that the prevalence of opioid use disorder (OUD) in chronic pain patients is higher among those with PTSD than those without this disorder.

AIM

To perform a systematic review on the association between PTSD, chronic non-cancer pain (CNCP), and opioid intake (i.e., prescription, misuse, and abuse).

METHODS

We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The Patient, Intervention, Comparator, and Outcomes (PICOS) criteria were formulated a priori in the protocol of the systematic review. A search was conducted of the PROSPERO database. In March 2019, searches were also conducted of 5 other databases: PubMed, MEDLINE, PsycINFO, Web of Science, and PILOTS. The Scottish Intercollegiate Guidelines Network checklist for cohort studies was used to assess the selected studies for their methodological quality and risk of bias. Each study was evaluated according to its internal validity, participant sampling, confounding variables, and the statistical analysis.

RESULTS

A total of 151 potentially eligible studies were identified of which 17 were retained for analysis. Only 10 met the selection criteria. All the studies were published between 2008 and 2018 and were conducted in the United States. The eligible studies included a total of 1622785 unique participants. Of these, 196516 had comorbid CNCP and PTSD and were consuming opiates. The participants had a cross-study mean age of 35.2 years. The majority of participants were men (81.6%). The most common chronic pain condition was musculoskeletal pain: back pain (47.14% across studies; range: 16%-60.6%), arthritis and joint pain (31.1%; range: 18%-67.5%), and neck pain (28.7%; range: 3.6%-63%). In total, 42.4% of the participants across studies had a diagnosis of PTSD (range: 4.7%-95%). In relation to opioid intake, we identified 2 different outcomes: opioid prescription and OUD. All the studies reported evidence of a greater prevalence of PTSD in CNCP patients who were receiving prescribed opioids and that PTSD was associated with OUD in CNCP patients.

CONCLUSION

Opioid analgesic prescription as the treatment of choice for CNCP patients should include screening for baseline PTSD to ensure that these drugs are safely consumed.

Use of Medicinal Cannabis and Synthetic Cannabinoids in Post-Traumatic Stress Disorder (PTSD): A Systematic Review

Background and Objectives: Post-traumatic stress disorder (PTSD) is a common psychiatric disorder resulting from a traumatic event, is manifested through hyperarousal, anxiety, depressive symptoms, and sleep disturbances. Despite several therapeutic approaches being available, both pharmacological and psychological, recently a growing interest has developed in using cannabis and synthetic cannabinoids stems from their consideration as more efficient and better tolerated alternatives for the treatment of this condition. The present paper aims to evaluate the clinical and therapeutic potentials of medical cannabis and synthetic cannabinoids in treating PTSD patients. Methods: A systematic electronic search was performed, including all papers published up to May 2019, using the following keywords (((cannabis[Title/Abstract]) OR (synthetic cannabinoids [Title/Abstract])) AND ((PTSD[Title/Abstract]) OR (Posttraumatic stress disorder[Title/Abstract]))) for the topics ‘Cannabis’, ‘Synthetic Cannabinoids’, ‘PTSD’, and MESH terms, on the PubMed, Cochrane Library, and Web of Science online databases. For data gathering purposes, PRISMA guidelines were followed. Results were organized into two groups, considering cannabis and synthetic cannabinoids as different therapeutic approaches for PTSD. Results: Present data show that cannabis and synthetic cannabinoids, both acting on the endocannabinoids system, may have a potential therapeutic use for improving PTSD symptoms, e.g., reducing anxiety, modulating memory-related processes, and improving sleep. Conclusions: Even though the current literature suggests that cannabis and synthetic cannabinoids may have a role in the treatment of PTSD, there is currently limited evidence regarding their safety and efficacy. Therefore, additional research is needed in order to better understand the effectiveness and therapeutic usage of these drug classes and monitor their safety.

Animal Models of PTSD: The Socially Isolated Mouse and the Biomarker Role of Allopregnanolone

Post-traumatic stress disorder (PTSD) is a debilitating undertreated condition that affects 8%-13% of the general population and 20%-30% of military personnel. Currently, there are no specific medications that reduce PTSD symptoms or biomarkers that facilitate diagnosis, inform treatment selection or allow monitoring drug efficacy. PTSD animal models rely on stress-induced behavioral deficits that only partially reproduce PTSD neurobiology. PTSD heterogeneity, including comorbidity and symptoms overlap with other mental disorders, makes this attempt even more complicated. Allopregnanolone, a neurosteroid that positively, potently and allosterically modulates GABAA receptors and, by this mechanism, regulates emotional behaviors, is mainly synthesized in brain corticolimbic glutamatergic neurons. In PTSD patients, allopregnanolone down-regulation correlates with increased PTSD re-experiencing and comorbid depressive symptoms, CAPS-IV scores and Simms dysphoria cluster scores. In PTSD rodent models, including the socially isolated mouse, decrease in corticolimbic allopregnanolone biosynthesis is associated with enhanced contextual fear memory and impaired fear extinction. Allopregnanolone, its analogs or agents that stimulate its synthesis offer treatment approaches for facilitating fear extinction and, in general, for neuropsychopathologies characterized by a neurosteroid biosynthesis downregulation. The socially isolated mouse model reproduces several other deficits previously observed in PTSD patients, including altered GABAA receptor subunit subtypes and lack of benzodiazepines pharmacological efficacy. Transdiagnostic behavioral features, including expression of anxiety-like behavior, increased aggression, a behavioral component to reproduce behavioral traits of suicidal behavior in humans, as well as alcohol consumption are heightened in socially isolated rodents. Potentials for assessing novel biomarkers to predict, diagnose, and treat PTSD more efficiently are discussed in view of developing a precision medicine for improved PTSD pharmacological treatments.

CB1 and ethanol effects on glutamatergic transmission in the central amygdala of male and female msP and Wistar rats

The central amygdala (CeA) is involved in the processing of anxiety and stress and plays a role in ethanol consumption. Chronic ethanol recruits stress systems in the CeA, leading to aversive withdrawal symptoms. Although primarily GABAergic, CeA contains glutamatergic afferents, and we have reported inhibitory effects of ethanol on locally evoked glutamatergic responses in CeA of Wistar and Marchigian Sardinian alcohol-preferring (msP) rats. Notably, msP rats display enhanced anxiety, stress and alcohol drinking, simulating the alcohol-dependent phenotype. Endocannabinoids are also involved in regulation of stress, and we previously demonstrated that cannabinoid receptor type 1 (CB₁ ) activation decreases CeA GABAergic signaling and blocks ethanol enhancement of GABAergic signaling. Here, we sought to investigate the effects of CB₁ activation (WIN 55,212-2; Win) and antagonism (AM251) with and without acute ethanol on glutamatergic synapses in CeA of female and male Wistar and msP rats. Using intracellular sharp pipette electrophysiology, we examined the effects of CB₁ compounds on locally evoked excitatory postsynaptic potentials (EPSPs) in CeA and compared effects between strains, gender and estrous cycle. Acute ethanol decreased EPSP amplitudes in Wistars, and in male but not female msPs. Win decreased EPSP amplitudes in msPs, and in male but not female Wistars. Combined application of Win and ethanol resulted in strain-specific effects in female rats. We found no tonic CB₁ signaling at glutamatergic synapses in CeA of any groups, and no interaction with ethanol. Collectively, these observations demonstrate sex-strain-specific differences in ethanol and endocannabinoid effects on CeA glutamatergic signaling.

The effect of post-traumatic stress disorder on the risk of developing prescription opioid use disorder: Results from the National Epidemiologic Survey on Alcohol and Related Conditions III

OBJECTIVE

To evaluate the effect of baseline post-traumatic stress disorder (PTSD) and each symptoms cluster on the risk of developing opioid use disorder (OUD) in those exposed to opioid painkillers and to assess the effect of comorbid PTSD and OUD on functioning, OUD severity, and treatment seeking compared with individuals with OUD only.

METHODS

We obtained data from 4025 individuals exposed to opioid painkillers from the National Epidemiologic Survey on Alcohol and Related Conditions III. We matched individuals with baseline PTSD with individuals without PTSD on demographics, developmental background, family history, personalities, and exposure to stressful life events with propensity score methodology. We controlled for clinical diagnoses and other risk factors that may have occurred after PTSD onset. Quality of life was assessed with the SF-12; the number of diagnostic criteria met indicated OUD severity.

RESULTS

Baseline PTSD predicted OUD after controlling for matching variables and other risk factors, including baseline mood/anxiety disorders and other substance use disorders (odds ratio[OR]: 1.58; 95% confidence interval[CI]: 1.14-2.17; p=0.02). Among individuals with PTSD, arousal/reactivity cluster predicted OUD. Individuals with comorbid PTSD and OUD had lower mean scores on the SF-12 scale and greater severity of OUD than individuals with OUD. There were no differences in help-seeking.

CONCLUSION

Baseline PTSD increases the risk of developing OUD after exposure to opioid painkillers. Clinicians should screen for PTSD diagnosis and arousal/reactivity symptoms prior to prescribing painkillers. Integrated treatments are strongly recommended for patients with this dual diagnosis.

Treatment of Comorbid Alcohol Dependence and Anxiety Disorder: Review of the Scientific Evidence and Recommendations for Treatment

Patients with alcohol-use disorders (AUDs) have a high prevalence of anxiety disorders (AnxDs). "Co-occurring disorders" refers to the coexistence of an AUD and/or drug related disorders with another non-addictive psychiatric disorder. The aim of this study was to assess the effectiveness of psychopharmacological treatments and psychotherapy in patients with AUD and AnxD and to propose recommendations for the treatment of patients with comorbid AnxDs and AUDs. Randomized clinical trials, meta-analyses, and clinical guidelines were retrieved from PubMed, Embase, and Cochrane databases. Paroxetine was found to be effective in social anxiety patients with alcohol dependence. Selective serotonin reuptake inhibitors (SSRIs), especially sertraline, showed effective results in posttraumatic stress disorder and in comorbid AnxD-AUD. However, SSRIs should be used with caution when patients are actively drinking because they may increase alcohol consumption. Buspirone, gabapentin, and pregabalin were found to be effective in comorbid AnxD-AUD. The treatment of dual AnxDs should start as early as possible. Since AUDs and AnxDs can reinforce each other, treatments targeting both pathologies can be effective. Women suffer from higher levels of stress and AnxDs than men, and they are also more vulnerable to maintaining alcohol consumption levels. Further research is needed in this comorbid patient population, including the study of different types of patients and gender perspectives.

Dual Diagnosis: Coexisting Substance Use Disorders and Psychiatric Disorders

Dual diagnosis is a prevalent and serious health problem. These disorders challenge psychiatric mental health and addiction nurses to treat 2 distinct disorders. Despite advances in the treatment of these disorders, there remains a void in the ideal approach. This article offers psychiatric nurses opportunities to improve their expertise in the identification of vulnerable or high-risk populations by using integrated screening and brief interventions to discern treatment options. Patients who require comprehensive treatment to stabilize 1 or both disorders further challenge nurses to have a basic understanding of the powerful effects of substance use on psychiatric conditions and vice versa.

Epigenetic mechanisms of alcoholism and stress-related disorders

Stress-related disorders, such as anxiety, early life stress, and posttraumatic stress disorder appear to be important factors in promoting alcoholism, as alcohol consumption can temporarily attenuate the negative affective symptoms of these disorders. Several molecules involved in signaling pathways may contribute to the neuroadaptation induced during alcohol dependence and stress disorders, and among these, brain-derived neurotrophic factor (BDNF), corticotropin releasing factor (CRF), neuropeptide Y (NPY) and opioid peptides (i.e., nociceptin and dynorphin) are involved in the interaction of stress and alcohol. In fact, alterations in the expression and function of these molecules have been associated with the pathophysiology of stress-related disorders and alcoholism. In recent years, various studies have focused on the epigenetic mechanisms that regulate chromatin architecture, thereby modifying gene expression. Interestingly, epigenetic modifications in specific brain regions have been shown to be associated with the neurobiology of psychiatric disorders, including alcoholism and stress. In particular, the enzymes responsible for chromatin remodeling (i.e., histone deacetylases and methyltransferases, DNA methyltransferases) have been identified as common molecular mechanisms for the interaction of stress and alcohol and have become promising therapeutic targets to treat or prevent alcoholism and associated emotional disorders.

Effects of the combination of metyrapone and oxazepam on cocaine-induced increases in corticosterone in the medial prefrontal cortex and nucleus accumbens

We have previously demonstrated that a combination of drugs (i.e., metyrapone and oxazepam) known to attenuate HPA-axis activity effectively decreases cocaine self-administration and cue reactivity in rats. However, we did not find changes in plasma corticosterone that matched the behavioral effects we observed, indicating that a different mechanism of action must be involved. Therefore, we hypothesized that the combination of metyrapone and oxazepam attenuates cocaine taking and seeking by decreasing cocaine-induced increases in corticosterone in the brain. Male rats were implanted with guide cannulae targeting the medial prefrontal cortex or nucleus accumbens. After the rats recovered from surgery, the microdialysis session was conducted. Rats were housed in the experimental chamber and the dialysis probes inserted into the guide cannulae the night before the session. The following day, dialysate samples were collected over a five-hour session. Baseline samples were collected for the first two hours, every 20min. Samples were then collected following administration of cocaine (15mg/kg, ip). Before injections of cocaine, rats were pretreated with either vehicle or the combination of metyrapone (50mg/kg, ip) and oxazepam (10mg/kg, ip). The administration of cocaine resulted in an increase in corticosterone in the medial prefrontal cortex following vehicle pretreatment, which was not observed in the nucleus accumbens. This cocaine-induced increase in corticosterone was attenuated by metyrapone/oxazepam. Reducing cocaine-induced increases in corticosterone in the medial prefrontal cortex might represent a novel mechanism through which the combination of metyrapone/oxazepam produces its behavioral effects.

Posttraumatic Stress Disorder and Alcohol Use Disorder: A Critical Review of Pharmacologic Treatments

Treatment of alcohol use disorder (AUD) is complicated by the presence of psychiatric comorbidity including posttraumatic stress disorder (PTSD). This is a critical review of the literature to date on pharmacotherapy treatments of AUD and PTSD. A systematic literature search using PubMed MESH terms for alcohol and substance use disorders, PTSD, and treatment was undertaken to identify relevant randomized controlled trials (RCTs). The studies were independently evaluated (ILP and TLS) and those that evaluated the efficacy of a pharmacotherapy for individuals diagnosed with AUD and PTSD and were RCTs were selected. Studies were grouped in 3 categories: (i) those that evaluated first-line treatments for PTSD, (ii) those that evaluated medications to target AUD, and (iii) those that evaluated medications hypothesized to be effective in targeting alcohol consumption as well as PTSD symptoms. Nine RCTs were identified; 3 focused on medications to treat PTSD, 4 focused on AUD, and 3 to target both. One study included both a medication to treat PTSD and 1 to treat AUD so was discussed twice. All but 1 of the studies found that PTSD symptoms and drinking outcomes improved significantly over time. There is not 1 agent with clear evidence of efficacy in this comorbid group. The results for medications to treat PTSD are inconclusive because of contradictory results. There was weak evidence to support the use of medications to treat AUD among those with comorbidity with PTSD. Findings for medications that were hypothesized to treat both disorders were also contradictory. Most studies provided a combination of interventions to treat both disorders. Despite the contradictory results, this review suggests that individuals with AUD and comorbid PTSD can safely be prescribed medications used in noncomorbid populations and patients improve with treatment.

Neurobiology of comorbid post-traumatic stress disorder and alcohol-use disorder

Post-traumatic stress disorder (PTSD) and alcohol-use disorder (AUD) are highly comorbid in humans. Although we have some understanding of the structural and functional brain changes that define each of these disorders, and how those changes contribute to the behavioral symptoms that define them, little is known about the neurobiology of comorbid PTSD and AUD, which may be due in part to a scarcity of adequate animal models for examining this research question. The goal of this review is to summarize the current state-of-the-science on comorbid PTSD and AUD. We summarize epidemiological data documenting the prevalence of this comorbidity, review what is known about the potential neurobiological basis for the frequent co-occurrence of PTSD and AUD and discuss successes and failures of past and current treatment strategies. We also review animal models that aim to examine comorbid PTSD and AUD, highlighting where the models parallel the human condition, and we discuss the strengths and weaknesses of each model. We conclude by discussing key gaps in our knowledge and strategies for addressing them: in particular, we (1) highlight the need for better animal models of the comorbid condition and better clinical trial design, (2) emphasize the need for examination of subpopulation effects and individual differences and (3) urge cross-talk between basic and clinical researchers that is reflected in collaborative work with forward and reverse translational impact.

Long-Lasting Impairment of mGluR5-Activated Intracellular Pathways in the Striatum After Withdrawal of Cocaine Self-Administration

BACKGROUND

Cocaine addiction continues to be a major heath concern, and despite public health intervention there is a lack of efficient pharmacological treatment options. A newly identified potential target are the group I metabotropic glutamate receptors, with allosteric modulators showing particular promise.

METHODS

We evaluated the capacity of group I metabotropic glutamate receptors to induce functional responses in ex vivo striatal slices from rats with (1) acute cocaine self-administration, (2) chronic cocaine self-administration, and (3) 60 days cocaine self-administration withdrawal by Western blot and extracellular recordings of synaptic transmission.

RESULTS

We found that striatal group I metabotropic glutamate receptors are the principal mediator of the mGluR1/5 agonist (RS)-3,5-dihydroxyphenylglycine-induced cAMP responsive-element binding protein phosphorylation. Both acute and chronic cocaine self-administration blunted group I metabotropic glutamate receptor effects on cAMP responsive-element binding protein phosphorylation in the striatum, which correlated with the capacity to induce long-term depression, an effect that was maintained 60 days after chronic cocaine self-administration withdrawal. In the nucleus accumbens, the principal brain region mediating the rewarding effects of drugs, chronic cocaine self-administration blunted group I metabotropic glutamate receptor stimulation of extracellular signal-regulated protein kinases 1/2 and cAMP responsive-element binding protein. Interestingly, the group I metabotropic glutamate receptor antagonist/inverse-agonist, 2-methyl-6-(phenylethynyl)pyridine hydrochloride, led to a specific increase in cAMP responsive-element binding protein phosphorylation after chronic cocaine self-administration, specifically in the nucleus accumbens, but not in the striatum.

CONCLUSIONS

Prolonged cocaine self-administration, through withdrawal, leads to a blunting of group I metabotropic glutamate receptor responses in the striatum. In addition, specifically in the accumbens, group I metabotropic glutamate receptor signaling to cAMP responsive-element binding protein shifts from an agonist-induced to an antagonist-induced cAMP responsive-element binding protein phosphorylation.

Post-traumatic stress disorder and opioid use disorder: A narrative review of conceptual models

Post-traumatic stress disorder is highly prevalent among individuals who suffer from opioid use disorder. Compared to individuals with opioid use disorder alone, those with post-traumatic stress disorder have a worse course of illness, occupational functioning, and physical health. The neurobiological pathways underlying each disorder overlap substantially, and there are multiple pathways through which these disorders may interact. This narrative review explores evidence underpinning 3 explanatory perspectives on comorbid post-traumatic stress disorder and opioid use disorder: The opioid susceptibility model (a.k.a.: the Self-Medication Hypothesis), the post-traumatic stress disorder susceptibility model, and the common factors model. Diagnostic implications, treatment implications, and directions for future research are discussed.