Changes in neural reward processing following Amplification of Positivity treatment for depression and anxiety: Preliminary findings from a randomized waitlist controlled trial

How to improve reward sensitivity - Predictors of long-term effects of a randomized controlled online intervention trial

BACKGROUND

Reward sensitivity is a central maintaining factor of depression. Current treatments fail at sufficiently and reliably modifying reward processing. Therefore, we employed interventions targeting reward sensitivity and evaluated the long-term efficacy of different online interventions, additionally exploring predictors of changes in reward sensitivity.

METHODS

This four-arm randomized controlled trial (RCT) tested the long-term stability of treatment effects during a four-month follow-up in 127 participants of a two-week online intervention (behavioral activation vs. mindfulness and gratitude vs. combination of both). In addition, we investigated predictors of treatment success defined as improvement in reward sensitivity. Predictors we investigated were depressive expectations, stress and the type of reward implemented in the exercises of the intervention (physical activities and social encounters).

RESULTS

The improvement concerning reward sensitivity, as well as the reduction of anhedonia and depressive symptoms was stable over a four-month follow-up. We did not find evidence for differences between the active intervention groups. Positive changes in depressive expectations were a significant predictor of long-term improvements in reward sensitivity.

LIMITATIONS

Only self-report measures were used and the interpretation of the long-term efficacy of the online interventions is limited since the waitlist control condition was not extended to the follow-up.

CONCLUSIONS

Clinicians should focus on violating depressive expectations to facilitate updating the prediction and anticipation of future rewarding experiences. This could be a vital mechanism of change in reward sensitivity. However, future research still needs to unravel what kind of interventions are most effective in targeting reward insensitivity.

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.

Hooking the Self Onto the Past: How Positive Autobiographical Memory Retrieval Benefits People With Social Anxiety

Do people with social anxiety (SA) benefit from positive memory retrieval that heightens self-relevant meaning? In this preregistered study, an analog sample of 255 participants with self-reported clinically significant symptoms of SA were randomly assigned to retrieve and process a positive social-autobiographical memory by focusing on either its self-relevant meaning (deep processing) or its perceptual features (superficial processing). Participants were then socially excluded and instructed to reimagine their positive memory. Analyses revealed that participants assigned to the deep processing condition experienced significantly greater improvements than participants in the superficial processing condition in positive affect, social safeness, and positive beliefs about others during initial memory retrieval and in negative and positive beliefs about the self following memory reactivation during recovery from exclusion. These novel findings highlight the potential utility of memory-based interventions for SA that work by "hooking" self-meaning onto recollections of positive interpersonal experiences that elicit feelings of social acceptance.

Reward processes in extinction learning and applications to exposure therapy

Anxiety disorders are common and highly distressing mental health conditions. Exposure therapy is a gold-standard treatment for anxiety disorders. Mechanisms of Pavlovian fear learning, and particularly fear extinction, are central to exposure therapy. A growing body of evidence suggests an important role of reward processes during Pavlovian fear extinction. Nonetheless, predominant models of exposure therapy do not currently incorporate reward processes. Herein, we present a theoretical model of reward processes in relation to Pavlovian mechanisms of exposure therapy, including a focus on dopaminergic prediction error signaling, coinciding positive emotional experiences (i.e., relief), and unexpected positive outcomes. We then highlight avenues for further research and discuss potential strategies to leverage reward processes to maximize exposure therapy response, such as pre-exposure interventions to increase reward sensitivity or post-exposure rehearsal (e.g., savoring, imaginal recounting strategies) to enhance retrieval and retention of learned associations.

Amplification of positivity for depression and anxiety: Neural prediction of treatment response

Psychosocial treatments targeting the positive valence system (PVS) in depression and anxiety demonstrate efficacy in enhancing positive affect (PA), but response to treatment varies. We examined whether individual differences in neural activation to positive and negative valence incentive cues underlies differences in benefitting from a PVS-targeted treatment. Individuals with clinically elevated depression and/or anxiety (N = 88, ages 18 to 55) participated in one of two randomized, waitlist-controlled trials of Amplification of Positivity (AMP; NCT02330627, NCT03196544), a cognitive and behavioral intervention targeting the PVS. Participants completed a monetary incentive delay (MID) task during fMRI acquisition at baseline measuring neural activation to the possibility of gaining or losing money. Change in PA from before to after treatment was assessed using the Positive and Negative Affect Schedule. No significant associations were observed between baseline neural activation during gain anticipation and AMP-related changes in PA in regions of interest (striatum and insula) or whole-brain analyses. However, higher baseline striatal and insula activation during loss anticipation was associated with greater increases in PA post-AMP. This study provides preliminary evidence suggesting neural reactivity to negative valence cues may inform who stands to benefit most from treatments targeting the PVS.

Positive and negative affect change following psychotherapeutic treatment for anxiety-related disorders: A systematic review and meta-analysis

BACKGROUND

Anxiety-related disorders feature elevated negative affect (NA), and in some cases, diminished positive affect (PA). It remains unclear how well extant psychotherapies for anxiety-related disorders improve PA versus NA.

METHODS

We systematically searched the Cochrane Central Register of Controlled Trials, PubMed, PsychInfo, and Web of Science databases. Records included studies involving (1) patients with a principal or co-principal diagnosis of at least one anxiety-related disorder (i.e., generalized anxiety, social anxiety, panic, agoraphobia, health anxiety, specific phobia, obsessive-compulsive disorder, or posttraumatic stress disorder), and (2) pre- and post-treatment PA and NA scores or a change index between pre- and post-treatment PA and NA scores. Effect sizes were calculated for meta-analyses.

RESULTS

Fourteen studies with 1001 adults with an anxiety-related disorder were included. Psychotherapeutic interventions included cognitive behavioral, present-centered, and imagery-based approaches. Treatments reduced NA (g = -0.90; 95%CI [-1.19, -0.61]) to a greater extent than they improved PA (g = 0.27; 95%CI [0.05, 0.59]), Z = -5.26, p < .001. The limited number of studies available precluded analyses of the relationship between changes in affect and symptoms.

LIMITATIONS

Results should be considered with caution given the small number and heterogeneity of included studies.

CONCLUSIONS

Current psychotherapeutic interventions for anxiety-related disorders may not improve PA and NA to comparable levels.

Effectiveness of behavioral activation and mindfulness in increasing reward sensitivity and reducing depressive symptoms - A randomized controlled trial

Reward insensitivity is a potential key mechanism regarding the maintenance of depression. However, there is a lack of research examining and comparing the effectiveness of different psychological interventions in modifying reward insensitivity. This four-arm randomized controlled trial (RCT) investigated a two-week online intervention. After screening for eligibility, a total of 336 participants were randomized, and 224 participated per-protocol. Participants were assigned to either a) behavioral activation, b) mindfulness and gratitude, c) a combination of both, or d) a waitlist control condition. They received videos and implemented daily exercises. Reward sensitivity and depressive symptoms served as primary outcomes. Behavioral activation and mindfulness significantly improved depressive symptoms and reward sensitivity. However, the effects of behavioral activation were not superior. The combination treatment versus the waiting group was insignificant regarding reward insensitivity. Explorative analyses revealed that all intervention groups reduced anhedonia substantially. Our findings imply that brief online interventions with behavioral activation and mindfulness-based approaches can impact reward insensitivity, while effects for a combination were less clear. Nonetheless, our results do not allow us to infer the differential effectiveness of the interventions. There is a clear need for treatments better targeting maintaining factors of depression, such as reward insensitivity. Clinical trial registration number: NCT05402150.

Improving social reward responsivity and social connectedness in psychotherapies for late-life depression: Engage & Connect as an example

Psychotherapies are effective in reducing late-life depression. Yet, about half of patients remain depressed at treatment end. Advances in neuroscience can inform simplified interventions that target key brain networks impacted by depression. Behavioral activation therapies that increase social connectedness may improve social reward responsivity and alter abnormalities of the Positive Valence System (PVS). Engage & Connect is an example for a scalable and simple neuroscience-informed psychotherapy, aimed to improve PVS functions and social reward responsivity by increasing engagement in rewarding social activities. Interventions that improve social reward responsivity can be promising first-line treatments for late-life depression in the community.

Positive affect treatment targets reward sensitivity: A randomized controlled trial

OBJECTIVE

Determine whether a novel psychosocial treatment for positive affect improves clinical status and reward sensitivity more than a form of cognitive behavioral therapy that targets negative affect and whether improvements in reward sensitivity correlate with improvements in clinical status.

METHOD

In this assessor-blinded, parallel-group, multisite, two-arm randomized controlled clinical superiority trial, 85 treatment-seeking adults with severely low positive affect, moderate-to-severe depression or anxiety, and functional impairment received 15 weekly individual therapy sessions of positive affect treatment (PAT) or negative affect treatment (NAT). Clinical status measures were self-reported positive affect, interviewer-rated anhedonia, and self-reported depression and anxiety. Target measures were eleven physiological, behavioral, cognitive, and self-report measures of reward anticipation-motivation, response to reward attainment, and reward learning. All analyses were intent-to-treat.

RESULTS

Compared to NAT, individuals receiving PAT achieved superior improvements in the multivariate clinical status measures at posttreatment, b = .37, 95% CI [.15, .59], t(109) = 3.34, p = .001, q = .004, d = .64. Compared to NAT, individuals receiving PAT also achieved higher multivariate reward anticipation-motivation, b = .21, 95% CI [.05, .37], t(268) = 2.61, p = .010, q = .020, d = .32, and higher multivariate response to reward attainment, b = .24, 95% CI [.02, .45], t(266) = 2.17, p = .031, q = .041, d = .25, at posttreatment. Measures of reward learning did not differ between the two groups. Improvements in reward anticipation-motivation and in response to reward attainment correlated with improvements in the clinical status measures.

CONCLUSIONS

Targeting positive affect results in superior improvements in clinical status and reward sensitivity than targeting negative affect. This is the first demonstration of differential target engagement across two psychological interventions for anxious or depressed individuals with low positive affect. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

[Late-life depression and frailty-Epidemiological, clinical and neurobiological associations]

BACKGROUND

Depression is the most common mental disorder in older adults and is influenced by age-related processes. Frailty is a well-established clinical expression of ageing that implies a state of increased vulnerability to stressor events as well as increased risks of disability, hospitalization and death. Neurobiological findings will disentangle the comorbidity of frailty and depression and may inform future management of depression in old age.

OBJECTIVE

This narrative review provides an overview of the comorbidity of late-life depression and frailty, with a focus on neuroscientific findings that are organized within the research domain criteria (RDoC) framework.

RESULTS

More than one third of old people with depression are affected by frailty, which results in more chronic depression and in poorer efficacy and tolerability of antidepressant medication. Depression and frailty share motivational and psychomotor characteristics, particularly apathy, decreased physical activity and fatigue. In patients with frailty, altered activity of the supplementary motor cortex is associated with motor performance deficits. Patients with late-life depression and apathy are characterized by abnormal structure and altered functional connectivity of the reward network and the salience network, along with altered functional connectivity of these networks with premotor brain areas.

CONCLUSION

Identifying frailty in older adults with depression is relevant for prognostic assessment and treatment. A better understanding of the neuronal mechanisms of comorbidity will provide potential targets for future personalized therapeutic interventions.

AI-based dimensional neuroimaging system for characterizing heterogeneity in brain structure and function in major depressive disorder: COORDINATE-MDD consortium design and rationale

BACKGROUND

Efforts to develop neuroimaging-based biomarkers in major depressive disorder (MDD), at the individual level, have been limited to date. As diagnostic criteria are currently symptom-based, MDD is conceptualized as a disorder rather than a disease with a known etiology; further, neural measures are often confounded by medication status and heterogeneous symptom states.

METHODS

We describe a consortium to quantify neuroanatomical and neurofunctional heterogeneity via the dimensions of novel multivariate coordinate system (COORDINATE-MDD). Utilizing imaging harmonization and machine learning methods in a large cohort of medication-free, deeply phenotyped MDD participants, patterns of brain alteration are defined in replicable and neurobiologically-based dimensions and offer the potential to predict treatment response at the individual level. International datasets are being shared from multi-ethnic community populations, first episode and recurrent MDD, which are medication-free, in a current depressive episode with prospective longitudinal treatment outcomes and in remission. Neuroimaging data consist of de-identified, individual, structural MRI and resting-state functional MRI with additional positron emission tomography (PET) data at specific sites. State-of-the-art analytic methods include automated image processing for extraction of anatomical and functional imaging variables, statistical harmonization of imaging variables to account for site and scanner variations, and semi-supervised machine learning methods that identify dominant patterns associated with MDD from neural structure and function in healthy participants.

RESULTS

We are applying an iterative process by defining the neural dimensions that characterise deeply phenotyped samples and then testing the dimensions in novel samples to assess specificity and reliability. Crucially, we aim to use machine learning methods to identify novel predictors of treatment response based on prospective longitudinal treatment outcome data, and we can externally validate the dimensions in fully independent sites.

CONCLUSION

We describe the consortium, imaging protocols and analytics using preliminary results. Our findings thus far demonstrate how datasets across many sites can be harmonized and constructively pooled to enable execution of this large-scale project.

Reducing Anhedonia in Major Depressive Disorder with Future Event Specificity Training (FEST): A Randomized Controlled Trial

Background

Improving future thinking, such as characteristics of specificity, detail, and use of mental imagery, may be one means to reduce anhedonia, particularly in a Major Depressive Episode (MDE) in which future thinking is impaired. The current study aimed to test this using a validated program, Future Event Specificity Training (FEST).

Methods

Participants (N = 177; 80.8% women; M age = 43.7, SD = 11.8) with a current depressive episode with anhedonia and high symptom severity were randomized to FEST or no FEST. Future thinking, anhedonia-related variables, and other clinical outcomes were assessed at baseline, one- and three-month follow-up.

Results

Relative to the control group, FEST was associated with significantly improved future thinking characteristics, a reduced likelihood of anhedonia (35.1% vs. 61.1%, p = .015), improvements on other anhedonia-related variables such as anticipatory (d = 0.63, p = .004) and anticipated pleasure for future events (d = 0.77, p < .001), and desirable clinical outcomes such as less people meeting criteria for an MDE (37.8% vs. 64.8%, p = .011), higher behavioural activation (d = 0.71, p = .001) and improved global functioning (d = 0.52, p = .017). Changes in future thinking were found to mediate the effect of FEST on anhedonia.

Conclusion

The quality of future thinking can be enhanced in Major Depression, and this leads to a substantially reduced likelihood of anhedonia, other significant clinical effects, and functional gains.

Anhedonia in Anxiety Disorders

Humans, like other animals, are fundamentally motivated to pursue rewarding outcomes and avoid aversive ones. Anxiety disorders are conceptualized, defined, and treated based on heightened sensitivity to perceived aversive outcomes, including imminent threats as well as those that are uncertain yet could occur in the future. Avoidance is the central strategy used to mitigate anticipated aversive outcomes - often at the cost of sacrificing potential rewards and hindering people from obtaining desired outcomes. It is for these reasons that people are often motivated to seek treatment. In this chapter, we consider whether and how anhedonia - the loss of interest in pursuing and/or reduced responsiveness to rewarding outcomes - may serve as a barrier to recovering from clinically impairing anxiety. Increasingly recognized as a prominent symptom in many individuals with elevated anxiety, anhedonia is not explicitly considered within prevailing theoretical models or treatment approaches of anxiety. Our goal, therefore, is to review what is known about anhedonia within the anxiety disorders and then integrate this knowledge into a functional perspective to consider how anhedonia could maintain anxiety and limit treatment response. Our overarching thesis is that anhedonia disrupts the key processes that are central to supporting anxiety recovery. We end this chapter by considering how explicitly targeting anhedonia in treatment can optimize outcomes for anxiety disorders.

Psychological Treatments for Anhedonia

Anhedonia, a loss of interest or pleasure in activities, is a transdiagnostic symptom that characterizes many individuals suffering from depression and anxiety. Most psychological interventions are designed to decrease negative affect rather than increase positive affect, and are largely ineffective for reducing anhedonia. More recently, affective neuroscience has been leveraged to inform treatments for anhedonia by targeting aspects of the Positive Valence Systems, including impairments in reward anticipation, reward responsiveness, and reward learning. In this chapter, we review the efficacy of treatments and, when possible, highlight links to reward constructs. Augmented behavioral approaches and targeted cognitive interventions designed to target reward anticipation, responsiveness, and learning show preliminary efficacy in reducing anhedonia, while there is a relative lack of treatments that target positive emotion regulation and reward devaluation. In addition to developing treatments that address these targets, the field will benefit from establishing standardized measurement of anhedonia across units of analysis, mapping mechanisms of change onto aspects of reward processing, and examining anhedonia outcomes in the long-term.