Anhedonia in substance use disorders: a systematic review of its nature, course and clinical correlates

Development and initial testing of mindful journey: a digital mindfulness-based intervention for promoting recovery from Substance use disorder

BACKGROUND/OBJECTIVES

There is a great unmet need for accessible adjunctive interventions to promote long-term recovery from substance use disorder (SUD). This study aimed to iteratively develop and test the initial feasibility and acceptability of Mindful Journey, a novel digital mindfulness-based intervention for promoting recovery among individuals with SUD.

PATIENTS/MATERIALS

Ten adults receiving outpatient treatment for SUD.

METHODS

Phase 1 (n = 5) involved developing and testing a single introductory digital lesson. Phase 2 included a separate sample (n = 5) and involved testing all 15 digital lessons (each 30- to 45-minutes) over a 6-week period, while also receiving weekly brief phone coaching for motivational/technical support.

RESULTS

Across both phases, quantitative ratings (rated on a 5-point scale) were all at or above a 4 (corresponding with 'agree') for key acceptability dimensions, such as usability, understandability, appeal of visual content, how engaging the content was, and helpfulness for recovery. Additionally, in both phases, qualitative feedback indicated that participants particularly appreciated the BOAT (Breath, Observe, Accept, Take a Moment) tool for breaking down mindfulness into steps. Qualitative feedback was used to iteratively refine the intervention. For example, based on feedback, we added a second core mindfulness tool, the SOAK (Stop, Observe, Appreciate, Keep Curious), and we added more example clients and group therapy videos. In Phase 2, 4 out of 5 participants completed all 15 lessons, providing initial evidence of feasibility. Participants reported that the phone coaching motivated them to use the app. The final version of Mindful Journey was a smartphone app with additional features, including brief on-the-go audio exercises and a library of mindfulness practices. Although, participants used these additional features infrequently.

CONCLUSIONS

Based on promising initial findings, future acceptability and feasibility testing in a larger sample is warranted. Future versions might include push notifications to facilitate engagement in the additional app features.

Inclusion of Individuals With Lived Experiences in the Development of a Digital Intervention for Co-Occurring Depression and Cannabis Use: Mixed Methods Investigation

BACKGROUND

Existing interventions for co-occurring depression and cannabis use often do not treat both disorders simultaneously and can result in higher rates of symptom relapse. Traditional in-person interventions are often difficult to obtain due to financial and time limitations, which may further prevent individuals with co-occurring depression and cannabis use from receiving adequate treatment. Digital interventions can increase the scalability and accessibility for these individuals, but few digital interventions exist to treat both disorders simultaneously. Targeting transdiagnostic processes of these disorders with a digital intervention-specifically positive valence system dysfunction-may yield improved access and outcomes.

OBJECTIVE

Recent research has highlighted a need for the inclusion of individuals with lived experiences to assist in the co-design of interventions to enhance scalability and relevance of an intervention. Thus, the purpose of this study is to describe the process of eliciting feedback from individuals with elevated depressed symptoms and cannabis use and co-designing a digital intervention, Amplification of Positivity-Cannabis Use Disorder (AMP-C), focused on improving positive valence system dysfunction in these disorders.

METHODS

Ten individuals who endorsed moderate to severe depressive symptoms and regular cannabis use (2-3×/week) were recruited online via Meta ads. Using a mixed methods approach, participants completed a 1-hour mixed methods interview over Zoom (Zoom Technologies Inc) where they gave their feedback and suggestions for the development of a mental health app, based on an existing treatment targeting positive valence system dysfunction, for depressive symptoms and cannabis use. The qualitative approach allowed for a broader investigation of participants' wants and needs regarding the engagement and scalability of AMP-C, and the quantitative approach allowed for specific ratings of intervention components to be potentially included.

RESULTS

Participants perceived the 13 different components of AMP-C as overall helpful (mean 3.9-4.4, SD 0.5-1.1) and interesting (mean 4.0-4.9, SD 0.3-1.1) on a scale from 1 (not at all) to 5 (extremely). They gave qualitative feedback for increasing engagement in the app, including adding a social component, using notifications, and being able to track their symptoms and progress over time.

CONCLUSIONS

This study highlights the importance of including individuals with lived experiences in the development of interventions, including digital interventions. This inclusion resulted in valuable feedback and suggestions for improving the proposed digital intervention targeting the positive valence system, AMP-C, to better match the wants and needs of individuals with depressive symptoms and cannabis use.

A smartphone app-based mindfulness intervention to enhance recovery from substance use disorders: Protocol for a pilot feasibility randomized controlled trial

Background

Poor long-term recovery outcomes after treatment (e.g., readmission to inpatient treatment) are common among individuals with substance use disorders (SUDs). In-person mindfulness-based treatments (MBTs) are efficacious for SUDs and may improve recovery outcomes. However, existing MBTs for SUD have limited public health reach, and thus scalable delivery methods are needed. A digitally-delivered MBT for SUDs may hold promise.

Methods

We recently developed Mindful Journey, a smartphone app-based adjunctive MBT for improving long-term recovery outcomes. In this paper, we present details on the app and describe the protocol for a single-site pilot feasibility randomized controlled trial of Mindful Journey. In this trial, individuals (n = 34) in an early phase of outpatient treatment for SUDs will be randomized to either treatment-as-usual (TAU) plus Mindful Journey, or TAU only. The trial will focus on testing the feasibility (e.g., engagement) and acceptability of the app (e.g., perceived usability and helpfulness for recovery), as well as feasibility of study procedures (e.g., assessment completion). The trial will incorporate ecological momentary assessment before and after treatment to assess mechanisms in real-time, including mindfulness, craving, difficulties with negative emotion regulation, and savoring. To examine the sensitivity to change of outcomes (substance use, substance-related problems, and psychological distress) and mechanism variables (noted above), we will test within-treatment-condition changes over time.

Discussion

The proposed pilot trial will provide important preliminary data on whether Mindful Journey is feasible and acceptable among individuals with SUDs.

Trial registration

ClinicalTrials.gov NCT05109507.

Decreased consumption of natural rewards in rhesus monkeys with prolonged methamphetamine abstinence

Rationale

Relapse to drug use is a major clinical challenge in the treatment of addictive disorders, including psychostimulant use and may be exacerbated by reduced sensitivity to natural, non-drug reward. Given the relatively limited set of outcomes, and short withdrawal time in rodent studies, we conducted a more detailed assessment of the response to natural rewards in methamphetamine (METH) naive versus exposed monkeys during long-term abstinence.

Methods

This study introduced an improved sucrose preference test (iSPT) to assess natural reward seeking and consumption in monkeys with long-term abstinence after methamphetamine (METH) use. The test was administered to sixteen naive monkeys and five METH exposed monkeys that had been abstinent for at least 3 months.

Results

METH exposed monkeys showed a lower sucrose preference score in both the iSPT (z = -2.10, p = 0.036) and the sucrose preference test (z = -2.61, p = 0.009). The sucrose preference score was significantly correlated with the latency of the establishment of stable sucrose-preference (r = -0.76, df = 46, p < 0.001) but not with the other variables. Furthermore, water-sucrose switch latency and switch times were significantly negatively correlated (r = -0.50, df = 20, p = 0.02).

Conclusion

These results show reductions in natural reward consumption during long-term methamphetamine abstinence.

From mood to use: Using ecological momentary assessments to examine how anhedonia and depressed mood impact cannabis use in a depressed sample

Anhedonia and depressed mood are two cardinal symptoms of major depressive disorder (MDD). Prior work has demonstrated that cannabis consumers often endorse anhedonia and depressed mood, which may contribute to greater cannabis use (CU) over time. However, it is unclear (1) how the unique influence of anhedonia and depressed mood affect CU and (2) how these symptoms predict CU over more proximal periods of time, including the next day or week (rather than proceeding weeks or months). The current study used data collected from ecological momentary assessment (EMA) in a sample with MDD (N = 55) and employed mixed effects models to detect and predict weekly and daily CU from anhedonia and depressed mood over 90 days. Results indicated that anhedonia and depressed mood were significantly associated with CU, yet varied at daily and weekly scales. Moreover, these associations varied in both strength and directionality. In weekly models, less anhedonia and greater depressed mood were associated with greater CU, and directionality of associations were reversed in the models looking at any CU (compared to none). Findings provide evidence that anhedonia and depressed mood demonstrate complex associations with CU and emphasize leveraging EMA-based studies to understand these associations with more fine-grained detail.

Cocaine disrupts action flexibility via glucocorticoid receptors

Many addictive drugs increase stress hormone levels. They also alter the propensity of organisms to prospectively select actions based on long-term consequences. We hypothesized that cocaine causes inflexible action by increasing circulating stress hormone levels, activating the glucocorticoid receptor (GR). We trained mice to generate two nose pokes for food and then required them to update action-consequence associations when one response was no longer reinforced. Cocaine delivered in adolescence or adulthood impaired the capacity of mice to update action strategies, and inhibiting CORT synthesis rescued action flexibility. Next, we reduced Nr3c1, encoding GR, in the orbitofrontal cortex (OFC), a region of the brain responsible for interlacing new information into established routines. Nr3c1 silencing preserved action flexibility and dendritic spine abundance on excitatory neurons, despite cocaine. Spines are often considered substrates for learning and memory, leading to the discovery that cocaine degrades the representation of new action memories, obstructing action flexibility.

Characterizing the dimensions of positive emotion functioning in young adult alcohol use and alcohol-related problems

Emotional functioning figures prominently in most contemporary models of alcohol use (Kassel & Veilleux, 2010). These models posit that alcohol use becomes reinforced due to its ability to regulate a person's affect (Sher & Grekin, 2007). A growing body of literature suggests that for youth, positive reinforcement (i.e., using alcohol to enhance positive feelings or to increase their duration) is a leading mechanism facilitating increased use (Emery & Simons 2020; Howard et al., 2015). However, few, if any, studies have examined the unique associations between multiple indicators of positive emotional functioning and alcohol use as well as alcohol-related problems. We aimed to fill this gap by using secondary data from large college student sample (N = 402) to characterize the unique associations between trait indicators of positive emotional functioning (i.e., positive affect, anhedonia, savoring, positive emotion dysregulation) and alcohol use as well as alcohol-related problems. Results indicated trait positive emotion dysregulation (difficulty managing intense positive emotions) was positively related to both alcohol consumption (IRR = 1.03, p =.019) and alcohol-related problems (IRR = 1.03, p =.001). Interestingly, trait savoring (i.e., ability to increase the intensity/duration of positive emotions) was positively related to alcohol consumption (IRR = 1.18, p =.049) and inversely related to problems (IRR = 0.86, p =.019). None of the other positive emotion indicators were significantly associated with either alcohol use or problems.

Using the Beck Depression Inventory to Assess Anhedonia: A Scale Validation Study

Anhedonia is central to several psychological disorders and a frequent target of psychosocial and pharmacological treatments. We evaluated the psychometric properties of two widely used anhedonia measures derived from the Beck Depression Inventory: a 3-item (BDI-Anh3) and a 4-item version (BDI-Anh4). We evaluated these measures in a large undergraduate sample, a community sample, and a clinical sample. Both the BDI-Anh3 and the BDI-Anh4 showed adequate internal consistency, with BDI-Anh4 performing somewhat better, across the three samples. Both measures showed good convergent and discriminant validity, even after controlling for shared variance with other items on the BDI. These findings indicate that both measures have sufficient reliability and validity to support their use by researchers and clinicians.

Personality characteristics, not clinical symptoms, are associated with anhedonia in a community sample: A preliminary investigation

Anhedonia is a salient transdiagnostic psychiatric symptom associated with increased illness severity and chronicity. Anhedonia is also present to varying degrees in non-clinical cohorts. Here, we sought to examine factors influencing expression of anhedonia. Participants (N = 335) were recruited through the Nathan Kline Institute-Rockland Sample, an initiative to deeply phenotype a large community sample across the lifespan. Utilizing a data-driven approach, we evaluated associations between anhedonia severity, indexed by Snaith-Hamilton Pleasure Scale (SHAPS), and 20 physical, developmental, and clinical measures, including Structured Clinical Interview for DSM-IV, Beck Depression Inventory, State-Trait Anxiety Inventory, NEO Five-Factor Inventory-3 (NEO-FFI-3), BMI, Hemoglobin A1C, and demography. Using a bootstrapped AIC-based backward selection algorithm, seven variables were retained in the final model: NEO-FFI-3 agreeableness, extraversion, and openness to experience; BMI; sex; ethnicity; and race. Though median SHAPS scores were greater in participants with psychiatric diagnoses (18.5) than those without (17.0) (U = 12238.5, z = 2.473, p = 0.013), diagnosis and symptom measures were not retained as significant predictors in the final robust linear model. Participants scoring higher on agreeableness, extraversion, and openness to experience reported significantly lower anhedonia. These results demonstrate personality as a mild-to-moderate but significant driver of differences in experiencing pleasure in a community sample.

Polish adaptation of the Dimensional Anhedonia Rating Scale (DARS) - validation in the clinical sample

Background

Anhedonia is the core symptom of depression. Its presence has been linked to worsened prognosis. The Dimensional Anhedonia Rating Scale (DARS) is a scale measuring desire, motivation, effort and consummatory pleasure across different domains. The aim of this paper was to confirm factor structure, assess reliability and validity of the Polish adaptation of the DARS in a clinical sample of patients with mood disorders and healthy controls (HC).

Methods

The study sample included 161 participants aged 18-65 years - 34 HC, 72 patients with bipolar disorder and 55 with major depressive disorder (in depressive episode or remission). Reliability of the Polish adaptation of the DARS was assessed using Cronbach's α and the average inter-item correlation (AIC). Convergent and divergent validity was established by Pearson's correlations between the DARS and the Snaith-Hamilton Pleasure Scale (SHAPS), the Quick Inventory of Depressive Symptomatology- self-report (QIDS-SR), the Hospital Anxiety and Depression Scale (HADS). The structure of the scale was examined by factor analysis.

Results

The factor structure was consistent with the original scale. Strong internal consistency for the DARS total score (Cronbach's α = 0.95) and all subscales (0.86-0.93) was observed. The DARS demonstrated good convergent (moderate to strong correlations with measures of anhedonia and depression) and divergent validity (weak correlations with anxiety level).

Conclusion

The Polish DARS demonstrated excellent internal consistency and very good validity. The scale is a valuable contribution to the psychometrics of anhedonia measures in patients with mood disorders.

Anhedonia and impulsivity in college alcohol use: A path analysis

OBJECTIVE

Alcohol use is a substantial problem among college students and has several negative consequences. The current study examined the associations between anhedonia and alcohol use and related problems via impulsive behavior (e.g., negative urgency, sensation seeking). We parsed anhedonia into four specific facets: consummatory, anticipatory, recreational, and social anhedonia.

PARTICIPANTS

Six hundred and forty college students aged 18-25 were included in the final analysis.

METHOD

Data were collected via Amazon Mechanical Turk. Self-report inventories assessing for anhedonia, alcohol use, impulsive behavior, and depressed mood were utilized.

RESULTS

Recreational consummatory anhedonia was negatively associated with alcohol use and alcohol-related problems through negative urgency. Recreational consummatory anhedonia also had significant negative associations with alcohol consumption via sensation seeking. Further, social anticipatory anhedonia was positively associated with alcohol use and related problems via negative urgency.

CONCLUSIONS

This study highlights important associations between anhedonia, impulsivity, and alcohol use and related problems.

Ecological investigation of the co-occurrence of posttraumatic stress disorder symptoms and cannabis use among community women experiencing intimate partner violence

BACKGROUND

Women experiencing intimate partner violence (IPV) are at increased risk for developing hazardous patterns of cannabis use. Research suggests that women experiencing IPV use cannabis to cope with posttraumatic stress disorder (PTSD) symptoms. To advance research, we used experience sampling methods to explicate the within-day concurrent and proximal relations between PTSD symptom clusters and cannabis use among women experiencing IPV.

METHOD

Participants were 145 community women (M age = 40.66, 41.6% white, 31.4% Black, 10.9% Hispanic or Latina, 8% American Indian/Alaska Native, 5.8% Bi-/multi-racial) experiencing IPV and using substances who completed three surveys a day for 30 days.

RESULTS

Externalizing behavior (OR = 1.37, 95% CI [1.15, 1.65], p < 0.001) and dysphoric arousal (OR = 1.27, 95% CI [1.09, 1.49], p = 0.002) PTSD symptom clusters were associated with cannabis use reported in the same survey period. Results from the lagged models found no proximal associations between PTSD symptom clusters and cannabis use.

CONCLUSIONS

Results highlight the acute effects of externalizing behavior and dysphoric arousal PTSD symptoms on cannabis use among women experiencing IPV. These findings may inform prevention and intervention efforts for cannabis use in this population.

Patterns of demoralization and anhedonia during early substance use disorder treatment and associations with treatment attrition

BACKGROUND

Although depressive symptoms represent a promising therapeutic target to promote recovery from substance use disorders (SUD), heterogeneity in their diagnostic presentation often hinders the ability to effectively tailor treatment. We sought to identify subgroups of individuals varying in depressive symptom phenotypes (i.e., demoralization, anhedonia), and examined whether these subgroups were associated with patient demographics, psychosocial health, and treatment attrition.

METHODS

Patients (N = 10,103, 69.2 % male) were drawn from a dataset of individuals who presented for admission to SUD treatment in the US. Participants reported on their demoralization and anhedonia approximately weekly for the first month of treatment, and on their demographics, psychosocial health, and primary substance at intake. Longitudinal latent profile analysis examined patterns of demoralization and anhedonia with treatment attrition as a distal outcome.

RESULTS

Four subgroups of individuals emerged: (1) High demoralization and anhedonia, (2) Remitting demoralization and anhedonia, (3) High demoralization, low anhedonia, and (4) Low demoralization and anhedonia. Relative to the Low demoralization and anhedonia subgroup, all the other profiles were more likely to discontinue treatment. Numerous between-profile differences were observed with regard to demographics, psychosocial health, and primary substance.

LIMITATIONS

The racial and ethnic background of the sample was skewed towards White individuals; future research is needed to determine the generalizability of our findings to minoritized racial and ethnic groups.

CONCLUSIONS

We identified four clinical profiles that varied in the joint course of demoralization and anhedonia. Findings suggest specific subgroups might benefit from additional interventions and treatments that address their unique mental health needs during SUD recovery.

Deficits in consummatory reward relate to severity of cocaine use

BACKGROUND AND AIMS

Identifying modifiable neuropsychological factors associated with more severe CUD could improve CUD treatment. Impairments in processing of non-drug rewards may be one such factor. This study assessed the relationship between reward functioning and cocaine use severity using multi-modal measures of three distinct reward functions: consummatory reward (pleasure or "liking"); motivational reward ("wanting") and reward learning.

METHODS

Fifty-three adults with at least moderate CUD completed self-report and behavioral measures of consummatory reward, motivational reward and reward learning, and a composite cocaine use severity measure including quantity, frequency and life impacts of cocaine use. We conducted parallel Frequentist and Bayesian multiple regressions with measures of reward functioning as predictors of cocaine use severity.

RESULTS

Less self-reported ability to experience pleasure, a hypothesized measure of consummatory reward, significantly predicted greater severity after adjustment for covariates and multiple hypothesis testing, β = 0.39, t(38) = 2.86, p = 0.007. Bayesian analyses confirmed a highly likely association between severity and ability to experience pleasure, and provided moderate evidence for associations with willingness to exert effort and reward learning.

CONCLUSIONS

Our results suggest that less experience of subjective pleasure is related to greater cocaine use severity. This cross-sectional study cannot establish whether differences in consummatory reward are pre-existing, a result of CUD, or both. However, these results suggest interventions focused on increasing subjective pleasure, such as mindful "savoring", should be investigated for CUD.

Discrete emotions and global affect: Applying empirically driven approaches to experience sampling data to model state and trait affective structure and affect-alcohol use associations in a heavy drinking young-adult sample

Affective functioning is central to most contemporary models of alcohol use. However, the affective structure at the within- and between-person levels is rarely investigated nor is the differential predictive value of specific affect dimensions assessed across state and trait formats. We examined a) the structure of state and trait affect using experience sampling methodology (ESM) and b) predictive associations between the empirically derived affect facets and alcohol use. Participants were 92 heavy drinking college students aged 18-25 who completed 8 momentary assessments of their affect and drinking a day for 28-days. We found evidence for a single positive affect factor at both the within- (i.e., state) and between-person (i.e., trait) levels. We found a hierarchical factor structure for negative affect, represented by a general, superordinate dimension as well as facet-level sadness, anxiety, and anger dimensions. Associations between affect and alcohol use differed across trait and state levels and across specific types of negative affect. Lagged state positive affect and sadness as well as trait positive affect and sadness were inversely associated with drinking. Lagged state anxiety and trait general negative affect were positively associated with drinking. Thus, our study demonstrates how associations between drinking and affect can be studied in relation to general (e.g., general negative affect) and more specific aspects of affective experiences (e.g., sadness versus anxiety) concurrently within the same study and across trait and state levels of assessment.

Problematic social media use is associated with depression and similar to behavioral addictions: Physiological and behavioral evidence

While many studies have examined the relationship between problematic social media use (PSMU) and mental health disorders, little is known about reward responsiveness mechanisms that might be driving this relationship and the neurophysiological characteristics of PSMU. We surveyed 96 undergraduate students at a private liberal arts college in upstate NY. PSMU was assessed using the Social Media Disorder Scale. Fourteen Individuals endorsing in five or more and three or less categories on the Social Media Disorder Scale were offered and underwent resting state QEEG. Mental health was assessed with the Center for Epidemiological Studies Depression Scale Short Form, Social Interaction Anxiety Scale, Penn State Worry Questionnaire, the 10-item Perceived Stress Scale, and a locally developed measure of Substance Use Disorder. Reward and motivational systems were studied using the Brief Sensation Seeking Scale, Behavioral Inhibition/Behavioral Activation Scale, and Temporal Experience of Pleasure Scale. SMDS scores were associated with poorer mental health on all measures except substance use. SMDS scores were positively associated with the behavioral inhibition scale, and the anticipatory pleasure scale. QEEG results revealed a negative association of high PSMU and right central and frontal lobeta, right central beta, and a positive association with frontal alpha asymmetry. The study replicates findings that PSMU is associated with mental health issues. Further the pattern of reward response is different compared with other addictive behaviors. QEEG results are consistent with previous work in substance use and depression.

Associations between resting state functional brain connectivity and childhood anhedonia: A reproduction and replication study

BACKGROUND

Previously, a study using a sample of the Adolescent Brain Cognitive Development (ABCD)® study from the earlier 1.0 release found differences in several resting state functional MRI (rsfMRI) brain connectivity measures associated with children reporting anhedonia. Here, we aim to reproduce, replicate, and extend the previous findings using data from the later ABCD study 4.0 release, which includes a significantly larger sample.

METHODS

To reproduce and replicate the previous authors' findings, we analyzed data from the ABCD 1.0 release (n = 2437), from an independent subsample from the newer ABCD 4.0 release (excluding individuals from the 1.0 release) (n = 6456), and from the full ABCD 4.0 release sample (n = 8866). Additionally, we assessed whether using a multiple linear regression approach could improve replicability by controlling for the effects of comorbid psychiatric conditions and sociodemographic covariates.

RESULTS

While the previously reported associations were reproducible, effect sizes for most rsfMRI measures were drastically reduced in replication analyses (including for both t-tests and multiple linear regressions) using the ABCD 4.0 (excluding 1.0) sample. However, 2 new rsfMRI measures (the Auditory vs. Right Putamen and the Retrosplenial-Temporal vs. Right-Thalamus-Proper measures) exhibited replicable associations with anhedonia and stable, albeit small, effect sizes across the ABCD samples, even after accounting for sociodemographic covariates and comorbid psychiatric conditions using a multiple linear regression approach.

CONCLUSION

The most statistically significant associations between anhedonia and rsfMRI connectivity measures found in the ABCD 1.0 sample tended to be non-replicable and inflated. Contrastingly, replicable associations exhibited smaller effects with less statistical significance in the ABCD 1.0 sample. Multiple linear regressions helped assess the specificity of these findings and control the effects of confounding covariates.

Transdiagnostic brain correlates of self-reported trait impulsivity: A dimensional structure-symptom investigation

Impulsivity transcends psychiatric diagnoses and is often related to anhedonia. This ad hoc cross-sectional investigation explored 1) whether self-reported trait impulsivity mapped onto a common structural brain substrate across healthy controls (HCs) and psychiatric patients, and 2) in a more exploratory fashion, whether impulsivity and anhedonia were related to each other and shared overlapping brain correlates. Structural magnetic resonance imaging (sMRI) datasets from 234 participants including HCs (n = 109) and patients with opioid use disorder (OUD, n = 22), cocaine use disorder (CUD, n = 43), borderline personality disorder (BPD, n = 45) and schizophrenia (SZ, n = 15) were included. Trait impulsivity was measured with the Barratt Impulsiveness Scale (BIS-11) and anhedonia with a subscore of the Beck Depression Inventory (BDI). BIS-11 global score data were available for the entire sample, while data on the BIS-11 2nd order factors attentional, motor and non-planning were additionally in hand for a subsample consisting of HCs, OUD and BPD patients (n = 116). Voxel-based morphometry analyses were conducted for identifying dimensional associations between grey matter volume and impulsivity/anhedonia. Partial correlations were further performed to exploratory test the relationships between impulsivity and anhedonia and their corresponding volumetric brain substrates. Volume of the left opercular part of the inferior frontal gyrus (IFG) was negatively related to global impulsivity across the entire sample and specifically to motor impulsivity in the subsample of HCs, OUD and BPD patients. Across patients anhedonia expression was negatively correlated with left putamen volume. Although there was no relationship between global impulsivity and anhedonia across all patients, only across OUD and BPD patients anhedonia was positively associated with attentional impulsivity. Finally, also across OUD and BPD patients, motor impulsivity associated left IFG volume was positively linked with anhedonia-associated volume in the left putamen. Our findings suggest a critical role of left IFG volume in self-reported global impulsivity across healthy participants and patients with substance use disorder, BPD and SZ. Preliminary findings in OUD and BPD patients further suggests associations between impulsivity and anhedonia that are related to grey matter reductions in the left IFG and putamen.

Relapse Prevention and Prediction Strategies in Substance Use Disorder: A Scoping Review

BACKGROUND

Relapse prevention for those with substance use disorder (SUD) is an evolving practice. Initiatives focused on relapse prevention from other populations may provide the foundation for future considerations and recommendations for recovering anesthesia providers in the workplace. The purpose of this scoping review was to examine what is known about return-to-use prediction and prevention strategies in various populations struggling with SUDs to inform future considerations and implications for recovering anesthesia providers with a history of SUD.

METHODS

The Arksey and O'Malley framework was used to conduct a scoping review of the literature. A systematic search was conducted across three databases (PubMed, CINAHL, and PsycInfo) for relevant literature. Search terms used were "measures predicting relapse in substance use disorder" and "relapse prevention in substance use disorder AND anesthesia." Data from articles that met the eligibility criteria were extracted and summarized by the primary author.

RESULTS

The search identified 46 articles highlighting various relapse prediction and prevention strategies related to craving and stress, underlying biological factors, neuroimaging, and mindfulness. Relapse prediction and prevention strategies ranged from cell phone applications, monitoring biological markers, and functional neuroimaging of the brain.

CONCLUSIONS

Relapse is a concern for individuals with a history of SUD. For anesthesia providers, immediate access to powerful anesthesia medications requires return-to-use prediction and prevention strategies when anesthesia providers return to work after SUD treatment. Although some identified strategies are practical, more research is needed to predict and prevent return to use for recovering anesthesia providers.

Nicotinic and muscarinic acetylcholine receptor antagonism dose-dependently decreases sign- but not goal-tracking behavior in male rats

RATIONALE

Acetylcholinergic antagonists have shown some promise in reducing addiction-related behaviors in both preclinical and clinical studies. However, the psychological mechanisms by which these drugs are able to affect addictive behavior remain unclear. A particular key process for the development of addiction is the attribution of incentive salience to reward-related cues, which can be specifically measured in animals using a Pavlovian conditioned approach procedure. When confronted with a lever that predicts food delivery, some rats engage with the lever directly (i.e., they sign track), indicating attribution of incentive-motivational properties to the lever itself. In contrast, others treat the lever as a predictive cue and approach the location of impending food delivery (i.e., they goal track), without treating the lever itself as a reward.

OBJECTIVES

We tested whether systemic antagonism of the either nicotinic or muscarinic acetylcholine receptors would selectively affect sign- or goal-tracking behavior, indicating a selective effect on incentive salience attribution.

METHODS

A total of 98 male Sprague Dawley rats were either given the muscarinic antagonist scopolamine (100, 50, or 10 µg/kg i.p.) or the nicotinic antagonist mecamylamine (0.3, 1.0, or 3 mg/kg i.p.) before being trained on a Pavlovian conditioned approach procedure.

RESULTS

Scopolamine dose-dependently decreased sign tracking behavior and increased goal-tracking behavior. Mecamylamine reduced sign-tracking but did not affect goal-tracking behavior.

CONCLUSIONS

Antagonism of either muscarinic or nicotinic acetylcholine receptors can reduce incentive sign-tracking behavior in male rats. This effect appears to be specifically due to a reduction in incentive salience attribution since goal-tracking either increased or was not affected by these manipulations.

Social anhedonia affects the trajectory of internet addiction in the college students: A latent growth curve analysis

BACKGROUND/AIM

There is growing awareness that anhedonia plays a critical role in the development of Internet Addictions (IA). However, anhedonia is a multidimensional construct and different aspects of anhedonia may exert different effects on IA. This study was designed to distinguish the effects of social anhedonia and physical anhedonia on the developmental trajectory of IA among college students.

METHODS

A total of 3577 Chinese college freshmen (M_age = 18.01, SD = 0.77; 65.4 % girls) participated in a 2-year, four waves longitudinal tracking study. The latent growth curve model (LGCM) was constructed to examine the impacts of different types of anhedonia on the developmental trajectories of IA. Gender was also added to the conditional LGCM as time-invariant variable.

RESULTS

The results of unconditional LGCM showed a U-shape developmental trajectory of IA. Social anhedonia significantly affected the intercept (β = 0.468, p < 0.001) and significantly affected the linear slope (β = -0.259, p < 0.05), but not the quadratic slope (β = 0.293, p > 0.05). Physical anhedonia was not significantly associated with intercept, linear slope and quadratic slope. There was no sex difference in both initial levels and change rate of IA.

CONCLUSIONS

Social anhedonia while not physical anhedonia has prediction effect on IA. College students with high levels of social anhedonia experienced high levels of IA at baseline, and performed a slower rate in downward trend of IA. The findings of the current study provide implications for prevention of IA in college students.

Anhedonia and sensitivity to punishment in schizophrenia, depression and opiate use disorder

BACKGROUND

From a behavioural perspective anhedonia is defined as diminished interest in the engagement of pleasurable activities. Despite its presence across a range of psychiatric disorders, the cognitive processes that give rise to anhedonia remain unclear.

METHODS

Here we examine whether anhedonia is associated with learning from positive and negative outcomes in patients diagnosed with major depression, schizophrenia and opiate use disorder alongside a healthy control group. Responses in the Wisconsin Card Sorting Test - a task associated with healthy prefrontal cortex function - were fitted to the Attentional Learning Model (ALM) which separates learning from positive and negative feedback.

RESULTS

Learning from punishment, but not from reward, was negatively associated with anhedonia beyond other socio-demographic, cognitive and clinical variables. This impairment in punishment sensitivity was also associated with faster responses following negative feedback, independently of the degree of surprise.

LIMITATIONS

Future studies should test the longitudinal association between punishment sensitivity and anhedonia also in other clinical populations controlling for the effect of specific medications.

CONCLUSIONS

Together the results reveal that anhedonic subjects, because of their negative expectations, are less sensitive to negative feedbacks; this might lead them to persist in actions leading to negative outcomes.

Behavioral activation for smoking cessation and the prevention of smoking cessation-related weight gain: A randomized trial

BACKGROUND

Post-cessation weight gain (PCWG) is an obstacle to smoking cessation. This trial evaluated a behavioral intervention targeting alternative rewards to smoking and high calorie snacking to promote smoking cessation while mitigating PCWG.

METHODS

Adult smokers (n = 288; 119 females, 169 males) received eight weeks of transdermal nicotine and were randomized to eight sessions of behavioral activation for smoking cessation and the mitigation of PCWG (BAS+) or standard smoking cessation counseling (SC). Primary outcomes were 7-day point prevalence abstinence and PCWG 26 weeks after the target quit date. Change in caloric intake from pre-treatment through the 26-week follow-up was a secondary outcome. Data were collected from September 2016 to February 2021, and analyses were completed in July 2022.

RESULTS

BAS+ and SC did not differ in smoking abstinence rates at the 26-week follow-up (OR=0.80, 95%CI 0.50-1.27, p = 0.34; 18% versus 23%). There were no significant differences in PCWG between BAS+ and SC who were 7-day point prevalence abstinent (β = -0.29, 95%CI -2.13 to 1.65, p = 0.77; 2.60 versus 2.20 pounds, respectively) or among those continuously abstinent (5.78 versus 5.34 pounds, respectively). There were no significant differences in caloric intake between BAS+ and SC from baseline to the 26-week follow-up (β = 110.65, 95%CI -96.72 to 318.02, p = 0.30; -19.1 versus -116.9 kcals/day, respectively).

CONCLUSIONS

The results do not support the efficacy of BAS+ for smoking cessation and the prevention of PCWG. These findings join a growing body of research highlighting the challenge of minimizing PCWG and promoting smoking abstinence.

"Don't [ruminate], be happy": A cognitive perspective linking depression and anhedonia

Anhedonia, a lack of pleasure in things an individual once enjoyed, and rumination, the process of perseverative and repetitive attention to specific thoughts, are hallmark features of depression. Though these both contribute to the same debilitating disorder, they have often been studied independently and through different theoretical lenses (e.g., biological vs. cognitive). Cognitive theories and research on rumination have largely focused on understanding negative affect in depression with much less focus on the etiology and maintenance of anhedonia. In this paper, we argue that by examining the relation between cognitive constructs and deficits in positive affect, we may better understand anhedonia in depression thereby improving prevention and intervention efforts. We review the extant literature on cognitive deficits in depression and discuss how these dysfunctions may not only lead to sustained negative affect but, importantly, interfere with an ability to attend to social and environmental cues that could restore positive affect. Specifically, we discuss how rumination is associated to deficits in working memory and propose that these deficits in working memory may contribute to anhedonia in depression. We further argue that analytical approaches such as computational modeling are needed to study these questions and, finally, discuss implications for treatment.

Dual Cannabinoid and Orexin Regulation of Anhedonic Behaviour Caused by Prolonged Restraint Stress

The endocannabinoid and orexin systems share many biological functions, including wakefulness, stress response, reward processing, and mood. While these systems work against one another with respect to arousal, chronic stress-induced downregulation of both systems often leads to anhedonia or the inability to experience pleasure from natural rewards. In the current study, a 24 h restraint stress test (24 h RST) reduced sucrose preference in adult male and female C57BL/6 mice. Prior to the stressor, subsets of mice were intraperitoneally administered cannabinoid and orexin receptor agonists, antagonists, and combinations of these drugs. Restraint mice that received the cannabinoid receptor type 1 (CB1R) antagonist SR141716A, orexin receptor type 2 (OX2R) agonist YNT-185, and the combination of SR141716A and YNT-185, exhibited less anhedonia compared to vehicle/control mice. Thus, the 24 h RST likely decreased orexin signaling, which was then restored by YNT-185. Receptor colocalization analysis throughout mesocorticolimbic brain regions revealed increased CB1R-OX1R colocalization from SR141716A and YNT-185 treatments. Although a previous study from our group showed additive cataleptic effects between CP55,940 and the dual orexin receptor antagonist (TCS-1102), the opposite combination of pharmacological agents proved additive for sucrose preference. Taken together, these results reveal more of the complex interactions between the endocannabinoid and orexin systems.

Enduring effects of early-life adversity on reward processes: A systematic review and meta-analysis of animal studies

Two-thirds of individuals experience adversity during childhood such as neglect, abuse or highly-stressful events. Early-life adversity (ELA) increases the life-long risk of developing mood and substance use disorders. Reward-related deficits has emerged as a key endophenotype of such psychiatric disorders. Animal models are invaluable for studying how ELA leads to reward deficits. However, the existing literature is heterogenous with difficult to reconcile findings. To create an overview, we conducted a systematic review containing multiple meta-analyses regarding the effects of ELA on reward processes overall and on specific aspects of reward processing in animal models. A comprehensive search identified 120 studies. Most studies omitted key details resulting in unclear risk of bias. Overall meta-analysis showed that ELA significantly reduced reward behaviors (SMD: -0.42 [-0.60; -0.24]). The magnitude of ELA effects significantly increased with longer exposure. When reward domains were analyzed separately, ELA only significantly dampened reward responsiveness (SMD: -0.525[-0.786; -0.264]) and social reward processing (SMD: -0.374 [-0.663; -0.084]), suggesting that ELA might lead to deficits in specific reward domains.

Prefrontal cortical response to natural rewards and self-reported anhedonia are associated with greater craving among recently withdrawn patients in residential treatment for opioid use disorder

Both anhedonia and craving are common among patients with opioid use disorder (OUD), and are associated with vulnerability to relapse. Although these constructs are theoretically linked relatively few studies have examined them together. In the current study, recently withdrawn patients (N = 71) in residential treatment for prescription OUD underwent a cue reactivity paradigm while being monitored with functional near-infrared spectroscopy (fNIRS). Patients also self-reported symptoms of anhedonia via the Snaith-Hamilton Pleasure Scale (SHAPS), while smartphone-based ecological momentary assessments (EMA) were used to measure craving levels. On average, lower right prefrontal cortex (PFC) activity in response to positive social stimuli was associated with higher craving (β = - 2.87; S.E. = 1.23; p = 0.02). Self-reported anhedonia moderated the association between PFC activity and craving (β = - 1.02; S.E. = 0.48; p = 0.04), such that patients with two or more anhedonic symptoms had a significant and stronger negative association between PFC activation to hedonically positive images and craving, compared to patients with fewer than two anhedonic symptoms, among whom the association was not significant. This finding provides evidence that higher levels of anhedonia among patients in residential treatment for OUD are associated with a stronger link between lower PFC response to positive social experiences and higher levels of craving, potentially increasing overall vulnerability to relapse.

Transcranial Magnetic Stimulation for Long-Term Smoking Cessation: Preliminary Examination of Delay Discounting as a Therapeutic Target and the Effects of Intensity and Duration

Background

Repetitive transcranial magnetic stimulation (rTMS) is a novel treatment for smoking cessation and delay discounting rate is novel therapeutic target. Research to determine optimal therapeutic targets and dosing parameters for long-term smoking cessation is needed. Due to potential biases and confounds introduced by the COVID-19 pandemic, we report preliminary results from an ongoing study among participants who reached study end prior to the pandemic.

Methods

In a 3 × 2 randomized factorial design, participants (n = 23) received 900 pulses of 20 Hz rTMS to the left dorsolateral prefrontal cortex (PFC) in one of three Durations (8, 12, or 16 days of stimulation) and two Intensities (1 or 2 sessions per day). We examined direction and magnitude of the effect sizes on latency to relapse, 6-month point-prevalence abstinence rates, research burden, and delay discounting rates.

Results

A large effect size was found for Duration and a medium for Intensity for latency to relapse. Increasing Duration increased the odds of abstinence 7–8-fold while increasing Intensity doubled the odds of abstinence. A large effect size was found for Duration, a small for Intensity for delay discounting rate. Increasing Duration and Intensity had a small effect on participant burden.

Conclusion

Findings provide preliminary support for delay discounting as a therapeutic target and for increasing Duration and Intensity to achieve larger effect sizes for long-term smoking cessation and will provide a pre-pandemic comparison for data collected during the pandemic.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier [NCT03865472].

Simulated opioid choice linked to opioid use disorder severity among veterans with chronic pain: initial validation of a novel paradigm

Background: Modeling addictive behavior among individuals with, or at risk for, opioid use disorder (OUD) in a way that is accurate, ethical, and reproducible presents a pressing concern. OUD risk is elevated among people with chronic pain on long-term opioid therapy (LTOT).Objectives: To provide initial validation of a novel opioid preference task as an index of OUD and its symptomatology among veterans prescribed opioids for chronic pain, a population at high risk for poor opioid-related outcomes. The relative ease by which such a paradigm can be implemented and performed in clinical contexts, including enabling investigation of opioid reinforcement and drug-seeking behavior while avoiding ethical pitfalls associated with direct drug administration, could make this task an attractive approach for potentially tracking OUD symptoms.Methods: We studied 87 veterans (74 males, 13 females) on LTOT for chronic pain - 33 of whom had OUD diagnoses. Participants completed a picture-viewing choice task to assess preference for viewing opioid-related images in comparison with standardized pleasant, unpleasant, neutral, and blank images. Opioid-related choice, measured by vigor of button pressing, was tested for association with OUD severity (measured by symptom counts), as well as craving and anhedonia.Results: Choice for opioid-related images was positively correlated with OUD severity (i.e., number of DSM-5 measured OUD symptoms) (r = 0.38, p < .001), particularly among those meeting diagnostic criteria for OUD (r = 0.47, p = .006). Neither craving nor anhedonia correlated with opioid-related choice.Conclusions: Our results provide initial validation for a new opioid picture-choice paradigm in patients with chronic pain.

Startle-elicited Event-Related Potentials to Affective Stimuli are Associated with Recent Illicit Opioid use among Patients Receiving Opioid Agonist Treatment

Opioid use disorder (OUD) has been linked to exaggerated attentional, affective, and arousal responses to opioid-related stimuli, as well as altered responses to other affective (eg, naturally rewarding or aversive) stimuli, particularly blunted responses to pleasant/rewarding stimuli. Both exaggerated responses to drug-related stimuli and reduced response to pleasant stimuli may influence the course of OUD and its treatment, however interpretation of studies thus far is limited by methodological issues. In the present study, we examined subjective ratings, and attenuation of the P3 component of the acoustic startle-evoked event-related potential (as a measure of attention), while viewing neutral, pleasant, unpleasant, and drug-related images. Participants prescribed opioid agonist treatment (OAT) for OUD (n = 82) were compared to a carefully-matched control group (n = 33) and to recently-abstinent participants with OUD (n = 22). Relative to controls, participants prescribed OAT gave higher positive valence ratings of drug images, and blunted valence responses to other affective images, but groups did not differ in terms of arousal ratings or P3 amplitude. Within the OAT group, linear modeling of associations between frequency of recent illicit opioid use and startle P3 amplitude found an association between increased recent illicit opioid use and reduced attention to pleasant, relative to unpleasant, images. The latter finding may have implications for interventions targeting cognitive biases in people with substance use disorder. In particular, they suggest that enhancing attention to pleasant stimuli may be as, if not more important, than the typical approach of trying to reduce attentional bias to drug-related stimuli.

Enduring disruption of reward and stress circuit activities by early-life adversity in male rats

In humans, early-life adversity (ELA) such as trauma, poverty, and chaotic environment is linked to increased risk of later-life emotional disorders including depression and substance abuse. These disorders involve underlying disruption of reward circuits and likely vary by sex. Accordingly, we previously found that ELA leads to anhedonia for natural rewards and cocaine in male rodents, whereas in females ELA instead increases vulnerability to addiction-like use of opioid drugs and palatable food. While these findings suggest that ELA-induced disruption of reward circuitry may differ between the sexes, the specific circuit nodes that are influenced by ELA in either sex remain poorly understood. Here, in adult male Sprague-Dawley rats, we ask how ELA impacts opioid addiction-relevant behaviors that we previously tested after ELA in females. We probe potential circuit mechanisms in males by assessing opioid-associated neuronal activation in stress and reward circuit nodes including nucleus accumbens (NAc), amygdala, medial prefrontal cortex (mPFC), and paraventricular thalamus. We find that ELA diminishes opioid-seeking behaviors in males, and alters heroin-induced activation of NAc, PFC, and amygdala, suggesting a potential circuit-based mechanism. These studies demonstrate that ELA leads to behavioral and neurobiological disruptions consistent with anhedonia in male rodents, unlike the increased opioid seeking we previously saw in females. Our findings, taken together with our prior work, suggest that men and women could face qualitatively different mental health consequences of ELA, which may be essential for individually tailoring future intervention strategies.

Development and validation of the Reward Deficiency Syndrome Questionnaire (RDSQ-29)

BACKGROUND

The reward deficiency syndrome (RDS) integrates psychological, neurological, and genetic factors of addictive, impulsive, and compulsive behaviors. However, to date, no instrument has been validated to assess the RDS construct.

AIMS

The present study developed and tested a tool to assess RDS.

METHODS

Data were collected on two college and university samples. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were performed on Sample 1 (N = 1726), and confirmatory analysis was conducted on an independent sample (N = 253). Impulsivity and sensation-seeking were assessed.

RESULTS

Based on EFAs, a 29-item Reward Deficiency Syndrome Questionnaire (RDSQ-29) was developed, containing four subscales (lack of sexual satisfaction, activity, social concerns, and risk-seeking behavior). CFA indicated good fit (comparative fit index (CFI) = 0.941; Tucker-Lewis index (TLI) = 0.933; root mean square error of approximation (RMSEA) = 0.068). Construct validity analysis showed strong relationship between sensation-seeking and the RDS scale.

CONCLUSION

The RDSQ-29 is an adequate scale assessing psychological and behavioral aspects of RDS. The RDSQ-29 assesses psychological and behavioral characteristics that may contribute to addictions generally.

Evaluating the item-level factor structure of anhedonia

BACKGROUND

Anhedonia has long been theorized to be a multidimensional construct, focusing on domains of reward stimuli and temporal relationship to reward. However, little empirical work has directly examined whether there is support for this assertion.

METHODS

The study used data from young adults from four independent samples (n = 2098). Participants completed multiple measures of anhedonia.

RESULTS

We used rigorous conducted exploratory and confirmatory factor analyses on items from six commonly used anhedonia measures to examine dimensions underlying anhedonia. Results suggested a four-factor solution with factors reflecting social reward, social disinterest, status/achievement, and physical/natural reward. The identified factors reflected broad content domains of pleasure, but not specific reward processes. The four factors were modestly associated with one another, suggesting a weak common underlying anhedonia trait that manifests across multiple dimensions. Factor scores were associated with personality measures, reward-related indices, and depression symptoms, supporting the validity of the factors.

LIMITATIONS

Participants were all young adults and we assessed anhedonia only at the level of self-report.

CONCLUSION

Anhedonia is a multidimensional construct. However, the dimensions of anhedonia only distinguish domains of, but not temporal processes of anhedonia. Future work should continue to refine the structures underlying the construct of anhedonia through iterative theory- and data-driven research and examine associations between anhedonia and clinical outcomes.

Effect of vortioxetine in subjects with major depressive and alcohol use disorders: a 6-month retrospective analysis

BACKGROUND

Major depressive disorder (MDD) and alcohol use disorder (AUD) are highly comorbid, with greater clinical complexity and psychosocial impairment. Several antidepressants have been used in this population, with mixed results. This preliminary study aims to investigate the effects of the multimodal antidepressant vortioxetine in MDD + AUD subjects.

METHODS

We retrospectively evaluated 57 MDD + AUD and 56 MDD outpatients, matched for baseline characteristics. Patients were assessed after 1, 3, and 6 months treatment with vortioxetine (10-20 mg/d, flexibly dosed) in combination with continuous psychosocial support. The primary outcome was improvement in depressive symptoms measured by the Montgomery-Åsberg Depression Rating Scale. We also investigated changes in anxiety, anhedonia, cognition, functioning, quality of life, and clinical global severity using the following instruments: Hamilton Anxiety Rating Scale, Snaith-Hamilton Pleasure Scale, Digit Symbol Substitution Test, Perceived Deficits Questionnaire-Depression, Functioning Assessment Short Test, Quality of Life Index, and Clinical Global Impression-Severity Scale.

RESULTS

Vortioxetine significantly improved mood in MDD + AUD patients (P < .001), with no differences when compared to MDD (P = .36). A substantial rate (45.6%) of comorbid subjects obtained clinical remission at endpoint (P = .36 vs MDD). We additionally observed baseline to endpoint improvements on all secondary outcomes (P < .001), with no significant difference between groups. Overall, vortioxetine was safe and well tolerated.

CONCLUSIONS

Given its effectiveness on mood, cognition, and functioning, its good safety and tolerability profile, and low potential for abuse, vortioxetine could represent a valid pharmacological intervention in MDD + AUD patients as part of an integrated therapeutic-rehabilitation program.

Neural mapping of anhedonia across psychiatric diagnoses: A transdiagnostic neuroimaging analysis

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Anhedonia is present in many different psychiatric disorders.

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Anhedonia has been associated with abnormal reward-related striatal dopamine functioning.

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This study tested whether transdiagnostic anhedonia expression mapped onto striatal volume.

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Our findings suggest volumetric abnormalities in the putamen and cerebellum as a common neural substrate of anhedonia severity that cut across psychiatric entities.

Anhedonia has been associated with abnormal reward-related striatal dopamine functioning in patients with different psychiatric disorders. Here, we tested whether anhedonia expression mapped onto striatal volume across several psychiatric diagnoses.

T1-weighted images from 313 participants including 89 healthy controls (HC), 22 patients with opioid use disorder (OUD), 50 patients with major depressive disorder (MDD), 45 patients with borderline personality disorder (BPD), 49 patients with first-episode psychosis (FEP), 43 patients with cocaine use disorder (CUD) and 15 patients with schizophrenia (SZ) were included. Anhedonia was assessed with subscores of the Beck Depression Inventory (BDI) and/or the Scale for the Assessment of Negative Symptoms (SANS). Voxel-based morphometry (VBM) was conducted for identifying dimensional symptom-structure associations using region of interest (ROI, dorsal and ventral striatum) and whole-brain analyses, as well as for group comparisons of striatal volume.

ROI analyses revealed significant negative relationships between putamen volume and BDI and SANS anhedonia scores across OUD, MDD, BPD, CUD and SZ patients (n = 175) and MDD, FEP and SZ patients (n = 114), respectively. Whole-brain VBM analyses confirmed these associations and further showed negative relationships between anhedonia severity and volume of the bilateral cerebellum. There were group differences in right accumbens volume, which however were not related to anhedonia expression across the different diagnoses.

Our findings indicate volumetric abnormalities in the putamen and cerebellum as a common neural substrate of anhedonia severity that cut across psychiatric entities.

Psychedelic-Assisted Therapy for Substance Use Disorders and Potential Mechanisms of Action

Substance use disorders (SUD) represent a significant public health issue with a high need for novel and efficacious treatment options. In light of this high unmet need, recent results reporting beneficial outcomes of psychedelic-assisted therapy in SUD are particularly relevant. However, several questions remain with regard to this treatment approach. The clinical mechanisms of action of psychedelic substances in the treatment of SUD are not well understood. Closing this knowledge gap is critical to inform and optimize the psychotherapeutic embedding of the acute substance administration. In this chapter, we discuss potential mechanisms that have implications on psychotherapeutic approaches including induced neuroplasticity, alterations in brain network connectivity, reward and emotion processing, social connectedness, insight, and mystical experiences. Furthermore, we outline considerations and approaches that leverage these mechanisms in order to optimize the therapeutic embedding by maximizing synergy between substance effects and psychotherapy. Understanding the mechanisms of action, developing psychotherapeutic approaches accordingly, and evaluating their synergistic efficacy in scientific studies will be critical to advance the framework of psychedelic-assisted therapy for addiction, create evidence-based approaches, and achieve the best treatment outcome for patients with SUD.

Anhedonia in Nicotine Dependence

Prior findings indicate that trait anhedonia enhances the likelihood of becoming a tobacco smoker, and preliminary evidence suggests that smoking abstinence leads to anhedonic states in some individuals and situations, and nicotine administration reduces anhedonic states. Nevertheless, many vital questions exist concerning relationships between anhedonia and nicotine dependence, including situational and individual difference factors that may moderate the strength of these associations. This chapter provides a critical review of the literature assessing relationships of anhedonia to nicotine dependence and the effects of acute nicotine through the lenses of the Research Domain Criteria's (RDoC) Positive Valence Systems (NIMH, RDoC changes to the matrix (CMAT) workgroup update: proposed positive valence domain revisions. A report by the national advisory mental health council workgroup on changes to the research domain criteria matrix, 2018) and the Situation x Trait Affective Response (STAR) model of nicotine's effects and nicotine dependence (Gilbert, Smoking individual differences, psychopathology, and emotion. Taylor and Francis, Washington, DC, 1995; Gilbert, Hum Psychopharmacol Clin Exp 12:S89-S102, 1997). The effects of nicotine and nicotine withdrawal on subjective, behavioral, and brain indices vary across the three RDoC Positive Valences Systems (Reward Responsiveness, Reward Learning, and Reward Valuation) in a manner that supports the research and potential clinical utility of using RDoC criteria and the STAR model to guide research and clinical innovation. We provide a revision of the STAR model that incorporates the three RDoC Positive Valence Systems with evidence that nicotine's effects on hedonic and affective processes vary as a function of the dominance/salience of (1) situational hedonic and affective cues and task/active coping cues, and (2) state executive functioning level/capacity and state reward sensitivity such that these effects of nicotine are maximal during states of suboptimal cognitive functioning and reward sensitivity, combined with low situational stimulus salience and low task-related cues/demands.

Negative symptoms in alcohol use disorder: A pilot study applying the two-factor model of negative symptoms to patients with alcohol use disorder

BACKGROUND AND AIMS

Alcohol Use Disorder (AUD) is characterized by a reduction in goal-directed behavior, with alcohol use taking precedence over other areas of life. These features in AUD resemble negative symptoms in schizophrenia, especially the reduction in motivation and pleasure (MAP). Given the clinical similarities of negative symptoms across diagnostic categories, it comes as a surprise that there are few investigations on negative symptoms in alcohol and other substance use disorders. To our knowledge, our study is the first to assess negative symptoms in AUD based on a two-factorial approach, and to investigate the interrelation of these dimensions with the severity of AUD, and alcohol craving.

MATERIALS AND METHODS

We examined a sample of 42 patients with AUD at the Psychiatric University Hospital in Zurich. Participants provided self-report and interview-based measures of the severity of AUD, negative symptoms, and alcohol craving. Finally, we used data from the electronic health records of the patients.

RESULTS

Patients with AUD show negative symptoms to a similar extent as patients with schizophrenia or bipolar disorder. We found a positive correlation between the extent of impairment within the MAP factor and overall severity of AUD. Furthermore, MAP negative symptoms were correlated with alcohol craving. In a linear regression, negative symptoms predicted alcohol craving whereas depression did not.

SUMMARY

Negative symptoms as conceptualized for schizophrenia are prevalent in patients with AUD and associated with the severity of AUD. More specifically, severity of AUD correlates with diminished motivation and pleasure, highlighting the importance of disturbances in motivational functions in AUD. This is further supported by the correlation between negative symptoms and craving, a hallmark of AUD. Taken together, our findings suggest that negative symptoms might be a highly relevant but hitherto often neglected therapeutic target in AUD.

Anhedonia in Posttraumatic Stress Disorder: Prevalence, Phenotypes, and Neural Circuitry

Anhedonia, the reduction of pleasure and reward-seeking behavior, is a transdiagnostic construct associated with a range of important health outcomes. As with other psychiatric disorders, anhedonia is a relatively common, though understudied, feature of posttraumatic stress disorder (PTSD) that is not adequately targeted by existing treatments. The purpose of this review is to describe the current state of the literature on anhedonia in PTSD and highlight areas for future research based on gaps in the existing evidence base. First, we review evidence for anhedonia symptoms as a distinct PTSD symptom factor and its associations with psychiatric comorbidity, disease trajectory, and quality of life outcomes, as well as describe theories that seek to explain the occurrence of anhedonia among individuals with PTSD. Second, we review evidence for behavioral and neural alterations in reward processing and circuitry, a marker of anhedonia, among individuals with PTSD and in animal models relevant to this disorder. Finally, we discuss key gaps in our understanding of anhedonia in PTSD and suggest areas for future research. Specifically, the timing of anhedonia symptom development and underlying circuit dysfunction in the trauma response trajectory, as well as potential differential associations of facets of anhedonia on clinical outcomes, remain unclear. Additionally, further research is needed to determine potential moderators of anhedonia, as well as the efficacy and effectiveness of psychotherapeutic, psychopharmacological, and device-based interventions targeting anhedonia among individuals with PTSD. A more thorough understanding of these topics will ultimately improve prevention and intervention efforts for PTSD.

Effects of topiramate on the association between affect, cannabis craving, and cannabis use in the daily life of youth during a randomized clinical trial

RATIONALE

Topiramate is an anticonvulsant currently under study for treating substance use disorders. Topiramate is thought to reduce substance use by attenuating craving and the rewarding effects of acute substance use through its concurrent GABAergic agonism and glutamatergic antagonism. Importantly, topiramate also impacts mood states central to many models of substance use. Despite this, little previous research has examined whether topiramate attenuates the respective associations of affect and craving with substance use.

OBJECTIVES

We conducted a secondary analysis of 63 youths that exhibited heavy cannabis use, aged 15-24 years, who were randomized in a double-blinded 6-week clinical trial comparing the effects of topiramate (up to 200 mg/day) and placebo on cannabis use. Ecological momentary assessment data were leveraged to model the role positive affect, negative affect, and craving on use over the 6-week period and whether topiramate attenuated associations between these feeling states and cannabis use.

RESULTS

Findings showed that craving was positively associated with use at the within-person level, while positive affect was negatively associated with use at the between-person level. Topiramate appears to attenuate the negative association of between-person positive affect (i.e., average) and cannabis use. Specifically, those in the placebo condition exhibited this inverse association between average positive affect and use while those in topiramate condition did not. No other significant affect or affect × medication condition interactions were observed.

CONCLUSIONS

These findings implicate craving and low positive affect as important risk factors for cannabis use in youth in treatment. Topiramate may attenuate this association for positive affect.

The Etiologic, Theory-Based, Ontogenetic Hierarchical Framework of Alcohol Use Disorder: A Translational Systematic Review of Reviews

Modern nosologies (e.g., ICD-11, DSM-5) for alcohol use disorder (AUD) and dependence prioritize reliability and clinical presentation over etiology, resulting in a diagnosis that is not always strongly grounded in basic theory and research. Within these nosologies, DSM-5 AUD is treated as a discrete, largely categorical, but graded, phenomenon, which results in additional challenges (e.g., significant phenotypic heterogeneity). Efforts to increase the compatibility between AUD diagnosis and modern conceptualizations of alcohol dependence, which describe it as dimensional and partially overlapping with other psychopathology (e.g., other substance use disorders) will inspire a stronger scientific framework and strengthen AUD's validity. We conducted a systematic review of 144 reviews to integrate addiction constructs and theories into a comprehensive framework with the aim of identifying fundamental mechanisms implicated in AUD. The product of this effort was the Etiologic, Theory-Based, Ontogenetic Hierarchical Framework (ETOH Framework) of AUD mechanisms, which outlines superdomains of cognitive control, reward, as well as negative valence and emotionality, each of which subsume narrower, hierarchically-organized components. We also outline opponent processes and self-awareness as key moderators of AUD mechanisms. In contrast with other frameworks, we recommend an increased conceptual role for negative valence and compulsion in AUD. The ETOH framework serves as a critical step towards conceptualizations of AUD as dimensional and heterogeneous. It has the potential to improve AUD assessment and aid in the development of evidence-based diagnostic measures that focus on key mechanisms in AUD, consequently facilitating treatment matching.

I feel good? Anhedonia might not mean "without pleasure" for people treated for opioid use disorder

Anhedonia is usually defined as partial or total loss of the capacity for pleasure. People with anhedonia in the context of major depressive disorder may have an unexpected capacity for event-related mood brightening, observable when mood is assessed dynamically (with smartphone-based ecological momentary assessment [EMA]) rather than only statically via questionnaire. We used EMA to monitor mood and pleasant events for 4 weeks in 54 people being treated with opioid agonist medication for opioid-use disorder (OUD), which is also associated with anhedonia, said to manifest especially as loss of pleasure from nondrug reward. We compared OUD patients' EMA reports with those of 47 demographically similar controls. Background positive mood was lower in OUD patients than in controls, as we hypothesized (Cohen ds = .85 to 1.32, 95% CIs [.66, 1.55]), although, contrary to our hypothesis, background negative mood was also lower (ds = .82 to .85, 95% CIs [.73, .94]). As hypothesized, instances of nondrug pleasure were as frequent in OUD patients as in controls-and were not rated much less pleasurable (d = .18, 95% CI [-.03, .35]). Event-related mood brightening occurred in both abstinent and nonabstinent OUD patients (ds = .18 to .37, CIs [-.01, .57]) and controls (ds = .04 to .60, CIs [-.17, .79]), brightening before each event began earlier for controls than OUD patients, but faded similarly postevent across groups. Our findings add to the evidence that anhedonia does not rule out reactive mood brightening, which, for people with OUD being treated on opioid agonist medication, can be elicited by nondrug activities. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The Reward Re-Training protocol: A novel intervention approach designed to alter the reward imbalance contributing to binge eating during COVID-19

Reduced exposure to social reward during the COVID-19 pandemic may result in both reduced reward response to day-to-day life activities and elevated reward response to substances or naturally rewarding stimuli (e.g., food). The combined hypo- and hyper-reward responses results in a reward imbalance, which has been noted as a relevant maintenance factor for eating disorders (EDs) characterized by binge eating. This registered report describes the protocol for a pilot randomized controlled trial (RCT) comparing supportive therapy to a novel treatment targeting reward imbalance (Reward Re-Training; RRT) for individuals with binge eating. Aims of the current study include to confirm feasibility and acceptability of RRT, to evaluate the ability of RRT to engage critical targets, and to provide preliminary estimates of efficacy in reducing ED symptoms at both posttreatment and 3-month follow-up. Sixty participants will be randomized to either RRT or supportive therapy. For both conditions, treatment will be delivered in 10 weekly group outpatient therapy sessions conducted remotely using videoconferencing software. Assessments will be conducted at baseline, mid-treatment, posttreatment, and 3-month follow-up to measure feasibility, acceptability, critical treatment targets (i.e., reward to day-to-day life activities, reward to palatable foods, social isolation, and loneliness), and ED symptoms.

State Anhedonia in Young Healthy Adults: Psychometric Properties of the German Dimensional Anhedonia Rating Scale (DARS) and Effects of the COVID-19 Pandemic

Healthy reward processing is a complex interplay of several components. Recent self-report measures of anhedonia, the decrease or loss of hedonic capacity, take this complexity into account. The Dimensional Anhedonia Rating Scale (DARS) measures interest, motivation, effort and consummatory pleasure across four domains: hobbies, food/drink, social activities and sensory experiences. In the present cross-sectional survey study, we validated the German version of the DARS in a sample of 557 young healthy adults. Factor structure as well as convergent and divergent validity were assessed. As a secondary aim, we examined the effects of the COVID-19 pandemic on state anhedonia and depression severity. Our results suggest good convergent and divergent validity and high internal consistency of the German DARS. The original differentiation of four factors mapping onto the four domains was confirmed and measurement invariance before and during the COVID-19 pandemic was established. We conclude that the DARS is a valid instrument to comprehensively assess state anhedonia in healthy German samples. Future studies should further assess the utility of the German DARS in clinical contexts. In line with many previous studies, participants during the pandemic reported significantly higher levels of depressive symptoms compared to participants in the months before. We found no indication that the COVID-19 pandemic affected state hedonic capacity.

A unifying translational framework to advance treatment research for comorbid PTSD and substance use disorders

We provide a unifying translational framework that can be used to synthesize extant lines of human laboratory research in four neurofunctional domains that underlie the co-occurrence of posttraumatic stress and substance use disorders (PTSD+SUD). We draw upon the Alcohol and Addiction Research Domain Criteria (AARDOC) to include executive functioning, negative emotionality, reward, and added social cognition from the National Institute of Mental Health (NIMH) Research Domain Criteria into our framework. We review research findings across each of the four domains, emphasizing human experimental studies in PTSD, SUD, and PTSD+SUD for each domain. We also discuss the implications of research findings for treatment development by considering new ways of conceptualizing risk factors and outcomes at the level of the individual patient, which will enhance treatment matching and advance innovations in intervention.

The Role of Mu-Opioids for Reward and Threat Processing in Humans: Bridging the Gap from Preclinical to Clinical Opioid Drug Studies

PURPOSE OF REVIEW

Opioid receptors are widely expressed in the human brain. A number of features commonly associated with drug use disorder, such as difficulties in emotional learning, emotion regulation and anhedonia, have been linked to endogenous opioid signalling. Whereas chronic substance use and misuse are thought to alter the function of the mu-opioid system, the specific mechanisms are not well understood. We argue that understanding exogenous and endogenous opioid effects in the healthy human brain is an essential foundation for bridging preclinical and clinical findings related to opioid misuse. Here, we will examine psychopharmacological evidence to outline the role of the mu-opioid receptor (MOR) system in the processing of threat and reward, and discuss how disruption of these processes by chronic opioid use might alter emotional learning and reward responsiveness.

RECENT FINDINGS

In healthy people, studies using opioid antagonist drugs indicate that the brain's endogenous opioids downregulate fear reactivity and upregulate learning from safety. At the same time, endogenous opioids increase the liking of and motivation to engage with high reward value cues. Studies of acute opioid agonist effects indicate that with non-sedative doses, drugs such as morphine and buprenorphine can mimic endogenous opioid effects on liking and wanting. Disruption of endogenous opioid signalling due to prolonged opioid exposure is associated with some degree of anhedonia to non-drug rewards; however, new results leave open the possibility that this is not directly opioid-mediated.

SUMMARY

The available human psychopharmacological evidence indicates that the healthy mu-opioid system contributes to the regulation of reward and threat processing. Overall, endogenous opioids can subtly increase liking and wanting responses to a wide variety of rewards, from sweet tastes to feelings of being connected to close others. For threat-related processing, human evidence suggests that endogenous opioids inhibit fear conditioning and reduce the sensitivity to aversive stimuli, although inconsistencies remain. The size of effects reported in healthy humans are however modest, clearly indicating that MORs play out their role in close concert with other neurotransmitter systems. Relevant candidate systems for future research include dopamine, serotonin and endocannabinoid signalling. Nevertheless, it is possible that endogenous opioid fine-tuning of reward and threat processing, when unbalanced by e.g. opioid misuse, could over time develop into symptoms associated with opioid use disorder, such as anhedonia and depression/anxiety.

Dopamine, endocannabinoids and their interaction in fear extinction and negative affect in PTSD

There currently exist few frameworks for common neurobiology between reexperiencing and negative cognitions and mood symptoms of PTSD. Adopting a dopaminergic framework for PTSD unites many aspects of unique symptom clusters, and this approach also links PTSD symptomology to common comorbidities with a common neurobiological deficiency. Here we review the dopamine literature and incorporate it with a growing field of research that describes both the contribution of endocannabinoids to fear extinction and PTSD, as well as the interactions between dopaminergic and endocannabinoid systems underlying this disorder. Based on current evidence, we outline an early, preliminary model that links re-experiencing and negative cognitions and mood in PTSD by invoking the interaction between endocannabinoid and dopaminergic signalling in the brain. These interactions between PTSD, dopamine and endocannabinoids may have implications for future therapies for treatment-resistant and comorbid PTSD patients.

Apathy is associated with poorer abstinence self-efficacy in individuals with methamphetamine dependence

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Used an apathy composite T-score approach validated in methamphetamine-dependence.

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Apathy, above other factors, associated with poorer drug abstinence self-efficacy.

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Methamphetamine use characteristics unrelated to drug abstinence self-efficacy.

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Social peer pressure was riskiest situation for potential methamphetamine relapse.

Background

Confidence in one’s ability to achieve and maintain drug abstinence (i.e., abstinence self-efficacy) is a strong predictor of substance use treatment outcomes. Neurobehavioral factors that may interfere with abstinence self-efficacy are less well established, particularly in methamphetamine (METH). This study investigated whether apathy, which is highly prevalent during active METH use and periods of abstinence, influences abstinence self-efficacy among METH dependent individuals.

Methods

Sixty-six participants with lifetime METH dependence and METH abuse/METH dependence diagnoses within the last 18 months (mean age [SD] = 39.5 years [10.7]), and no severe psychiatric or neurological diseases, completed the Methamphetamine Self-Efficacy Scale (MSES), alongside a comprehensive neurobehavioral evaluation. The MSES presents six situations that may lead to relapse and collects self-report ratings for two subscales: “Confidence” (i.e., confidence in one’s ability to abstain from using METH, or METH abstinence self-efficacy) and “Temptation” (i.e., how tempted one is to use METH) with regard to each situation. Apathy was measured using a composite T-score comprised of items and scales from three well-validated, self-report assessments.

Results

Multivariable linear regression found that higher Apathy T-scores were significantly associated with lower Confidence ratings (i.e., poorer METH abstinence self-efficacy; p < .05), independent of potentially relevant factors (e.g., Temptation to use METH, comorbid HIV disease, and neurocognitive impairment).

Conclusions

Elevated apathy may adversely impact one’s confidence to abstain from METH use. Findings highlight the importance of addressing apathy in order to improve METH abstinence self-efficacy, which may subsequently increase the likelihood of successful METH treatment outcomes.

Tryptophan depletion predicts lower positive affect in sexual minority men living with HIV who use methamphetamine

This longitudinal study with 76 sexual minority men living with HIV who use methamphetamine examined whether dysregulation of essential amino acid precursors for neurotransmitters at baseline predicted positive and negative affect at 15 months. After controlling for covariates including baseline positive affect, a higher baseline kynurenine/tryptophan (K/T) ratio independently predicted lower positive affect at 15 months (β = - 18.31; 95% CI = - 35.35, - 1.27; p = 0.036). Future clinical research should examine whether bio-behavioral interventions targeting tryptophan degradation could optimize treatments for people living with co-occurring HIV and stimulant use disorders.