Facilitation of emotion regulation with a single dose of escitalopram: A randomized fMRI study

Neural Markers of Emotion Reactivity and Regulation Before and After a Targeted Social Rejection: Differences Among Girls With and Without Suicidal Ideation and Behavior Histories

BACKGROUND

Suicidal thoughts and behaviors (STBs) are common among adolescent girls and increase risk for suicide death. Emotion regulation difficulties are linked with STBs, particularly in response to targeted social rejection. However, neural correlates of this link have not been investigated and may identify novel targets for interventions. Here, we examined neural correlates of emotion regulation before and after an experimentally delivered targeted social rejection in adolescent girls with STBs and girls without STBs (i.e., control participants).

METHODS

Girls (N = 138; age range, 9-15 years; mean [SD] age = 11.6 [1.79] years) completed a functional neuroimaging emotion regulation task. In the middle of the task, participants were socially rejected by an unfamiliar confederate whom the participants had elected to meet. Participants also completed a multimethod STB assessment.

RESULTS

Before rejection, girls with a history of STBs, compared with control participants, showed greater activation in the right superior frontal gyrus when passively viewing negative stimuli, and girls with suicidal behavior (SB) versus those without SB showed less activation in the right frontal pole during emotion regulation attempts. Following the rejection, girls with STBs, compared with control participants, showed greater activation in the right inferior frontal gyrus during emotion regulation.

CONCLUSIONS

Before social rejection, girls with SB versus without SB may not activate brain regions implicated in emotion regulation, suggesting a vulnerability to poor regulation at their baseline emotional state. After social rejection, girls with any history of STBs showed altered activation in a brain region strongly associated with inhibition and emotion regulation success, possibly reflecting increased effort at inhibiting emotional responses during regulation following stress exposure.

Serotonin and emotion regulation: the impact of tryptophan depletion on emotional experience, neural and autonomic activity

The involvement of serotonin in emotion and psychopathology has been extensively examined. Studies using acute tryptophan depletion (ATD) have found limited effects on mood and aggression, and one of the explanations suggests that serotonin may be involved in higher-order functions, such as emotion regulation. However, there is very limited evidence for this hypothesis. The present study investigated the impact of ATD on emotion regulation in a double-blind, placebo-controlled, crossover design. A sample of psychiatrically healthy men (N = 28) completed a cognitive task assessing reappraisal ability (i.e., the success of using reappraisal, an emotion regulation strategy, to modulate emotional responses), following ATD and placebo. EEG frontal activity and asymmetry, as well as heart-rate variability (HRV), also were assessed in the reappraisal task. Both frequentist and Bayesian methods were employed for statistical analysis. Results indicated that ATD reduced plasma tryptophan, and reappraisal was effective in modulating emotional experience in the emotion regulation task. However, ATD had no significant effect on reappraisal ability, frontal activity, and HRV. These results offer direct and compelling evidence that decreasing serotonin synthesis through ATD does not alter an emotion regulation ability that is considered crucial in mood and aggression and has been linked with transdiagnostic risk of psychopathology.

Review: The use of functional magnetic resonance imaging (fMRI) in clinical trials and experimental research studies for depression

Functional magnetic resonance imaging (fMRI) is a non-invasive technique that can be used to examine neural responses with and without the use of a functional task. Indeed, fMRI has been used in clinical trials and pharmacological research studies. In mental health, it has been used to identify brain areas linked to specific symptoms but also has the potential to help identify possible treatment targets. Despite fMRI's many advantages, such findings are rarely the primary outcome measure in clinical trials or research studies. This article reviews fMRI studies in depression that sought to assess the efficacy and mechanism of action of compounds with antidepressant effects. Our search results focused on selective serotonin reuptake inhibitors (SSRIs), the most commonly prescribed treatments for depression and ketamine, a fast-acting antidepressant treatment. Normalization of amygdala hyperactivity in response to negative emotional stimuli was found to underlie successful treatment response to SSRIs as well as ketamine, indicating a potential common pathway for both conventional and fast-acting antidepressants. Ketamine's rapid antidepressant effects make it a particularly useful compound for studying depression with fMRI; its effects on brain activity and connectivity trended toward normalizing the increases and decreases in brain activity and connectivity associated with depression. These findings highlight the considerable promise of fMRI as a tool for identifying treatment targets in depression. However, additional studies with improved methodology and study design are needed before fMRI findings can be translated into meaningful clinical trial outcomes.

Acute neurofunctional effects of escitalopram during emotional processing in pediatric anxiety: a double-blind, placebo-controlled trial

Anxiety disorders are the most common mental disorders in adolescents. However, only 50% of pediatric patients with anxiety disorders respond to the first-line pharmacologic treatments-selective serotonin reuptake inhibitors (SSRIs). Thus, identifying the neurofunctional targets of SSRIs and finding pretreatment or early-treatment neurofunctional markers of SSRI treatment response in this population is clinically important. We acquired pretreatment and early-treatment (2 weeks into treatment) functional magnetic resonance imaging during a continuous processing task with emotional and neutral distractors in adolescents with generalized anxiety disorder (GAD, N = 36) randomized to 8 weeks of double-blind escitalopram or placebo. Generalized psychophysiological interaction analysis was conducted to examine the functional connectivity of the amygdala while patients viewed emotional pictures. Full-factorial analysis was used to investigate the treatment effect of escitalopram on amygdala connectivity. Correlation analyses were performed to explore whether pretreatment and early (week 2) treatment-related connectivity were associated with treatment response (improvement in anxiety) at week 8. Compared to placebo, escitalopram enhanced emotional processing speed and enhanced negative right amygdala-bilateral ventromedial prefrontal cortex (vmPFC) and positive left amygdala-right angular gyrus connectivity during emotion processing. Baseline amygdala-vmPFC connectivity and escitalopram-induced increased amygdala-angular gyrus connectivity at week 2 predicted the magnitude of subsequent improvement in anxiety symptoms. These findings suggest that amygdala connectivity to hubs of the default mode network represents a target of acute SSRI treatment. Furthermore, pretreatment and early-treatment amygdala connectivity could serve as biomarkers of SSRI treatment response in adolescents with GAD. The trial registration for the study is ClinicalTrials.gov Identifier: NCT02818751.

Behavioral, cortical and autonomic effects of single-dose escitalopram on the induction and regulation of fear and disgust: Comparison with single-session psychological emotion regulation with reappraisal

INTRODUCTION

Adaptive and successful emotion regulation, the ability to flexibly exert voluntary control over emotional experience and the ensuing behavior, is vital for optimal daily functioning and good mental health. In clinical settings, pharmacological and psychological interventions are widely employed to modify pathological emotion processing and ameliorate its deleterious consequences.

METHODS

In this study, we investigated the acute effects of single-dose escitalopram on the induction and regulation of fear and disgust in healthy subjects. Furthermore, we compared these pharmacological effects with psychological emotion regulation that utilized a cognitive strategy with reappraisal. Emotion induction and regulation tasks were performed before and 4 h after ingestion of placebo or 10 mg escitalopram in a randomized, double-blind design. The International Affective Picture System (IAPS) was used as a source of images, with threat-related pictures selected for fear and disease and contamination-related pictures for disgust. Behavioral data, electrodermal activity (EDA), and functional near-infrared spectroscopy (fNIRS) recordings were collected.

RESULTS

Escitalopram significantly reduced emotion intensity for both fear and disgust during emotion induction, albeit with differing electrodermal and hemodynamic activity patterns for the two negative emotions. At rest, i.e., in the absence of emotive stimuli, escitalopram increased sympathetic activity during the fear but not during the disgust experiments. For both fear and disgust, emotion regulation with reappraisal was more effective in reducing emotion intensity compared to pharmacological intervention with escitalopram or placebo.

DISCUSSION

We concluded that emotion regulation with reappraisal and acute administration of escitalopram, but not placebo, reduce emotion intensity for both fear and disgust, with cognitive regulation being significantly more efficient compared to pharmacological regulation under the conditions of this study. Results from the fNIRS and EDA recordings support the concept of differential mechanisms of emotion regulation that could be emotion-specific.

REM density is associated with treatment response in major depression: Antidepressant pharmacotherapy vs. psychotherapy

Major depression is one of the most common psychiatric illnesses. Interestingly, a few studies have indicated the existence of depression subgroups, which respond differently to the available treatment options. Previously, sleep abnormalities have been suggested to indicate amenability to different treatment regimens. Thereby, especially REM-sleep parameters seem to play a prominent role, and REM-sleep dysregulation has been repeatedly discussed as a potential endophenotype of depression. With that said, estimating therapy outcome in order to choose the best line of treatment is of utmost importance to patients suffering from depression. The present study looks deeper into these clues by investigating the capability of polysomnographic sleep parameters to predict treatment response in depressed patients to either pharmacotherapy or psychotherapy. Moderately to severely depressed patients (n = 38) were randomly assigned to either psychotherapy (i.e. interpersonal psychotherapy) or pharmacotherapy (i.e., monotherapy with selective serotonin reuptake inhibitors, SSRI, or selective serotonin noradrenalin reuptake inhibitors, SSNRI). Prior to treatment, all patients underwent polysomnography in the sleep laboratory. After treatment, responders and non-responders of both treatment groups were compared regarding their baseline sleep parameters. Higher baseline REM density, i.e. the amount of rapid eye movements during REM sleep, predicted better response to antidepressant pharmacotherapy. In the psychotherapy group, the effect seemed reversed but was not statistically significant. No other sleep parameter predicted treatment response. Our findings support the notion that REM-sleep dysregulation is indeed indicative of a distinct endophenotype of depression and that pharmacotherapy with SSRI/SSNRI might be superior to psychotherapy in these patients.

Antidepressant treatment, not depression, leads to reductions in behavioral and neural responses to pain empathy

Major depressive disorder (MDD) has been hypothesized to lead to impairments in empathy. Previous cross-sectional studies did not disentangle effects of MDD itself and antidepressant treatment. In this first longitudinal neuroimaging study on empathy in depression, 29 patients with MDD participated in two functional magnetic resonance imaging (fMRI) sessions before and after 3 months of antidepressant therapy. We compared their responses to an empathy for pain task to a group of healthy controls (N = 35). All participants provided self-report ratings targeting cognitive (perspective taking) and affective (unpleasant affect) aspects of empathy. To control for general effects on processing of negative affective states, participants additionally underwent an electrical pain task. Before treatment, we found no differences in empathic responses between controls and patients with MDD. After treatment, patients showed significant decreases in both affective empathy and activity of three a priori selected brain regions associated with empathy for pain. Decreases in affective empathy were moreover correlated with symptom improvement. Moreover, functional connectivity during the empathy task between areas associated with affective (anterior insula) and cognitive (precuneus) empathy decreased between sessions in the MDD group. Neither cognitive empathy nor responses to painful electrical shocks were changed after treatment. These findings contradict previous cross-sectional reports of empathy deficits in acute MDD. Rather, they suggest that antidepressant treatment reduces the aversive responses triggered by exposure to the suffering of others. Importantly, this cannot be explained by a general blunting of negative affect, as treatment did not change self-experienced pain.

Regulating emotion through distancing: A taxonomy, neurocognitive model, and supporting meta-analysis

Distancing is a type of emotion regulation that involves simulating a new perspective to alter the psychological distance and emotional impact of a stimulus. The effectiveness and versatility of distancing relative to other types of emotion regulation make it a promising tool for clinical applications. However, the neurocognitive mechanisms of this tactic are unclear, and inconsistencies in terminology and methods across studies make it difficult to synthesize the literature. To promote more effective research, we propose a taxonomy of distancing within the broader context of emotion regulation strategies; review the effects of this tactic; and offer a preliminary neurocognitive model describing key cognitive processes and their neural bases. Our model emphasizes three components-self-projection, affective self-reflection, and cognitive control. Additionally, we present results from a supporting meta-analysis of neuroimaging studies of distancing. These efforts are presented within the overarching goals of supporting effective applications of distancing in laboratory, clinical, and other real-world contexts, and advancing understanding of the relevant high-level cognitive functions in the brain.

Trajectories in Cerebral Blood Flow Following Antidepressant Treatment in Late-Life Depression: Support for the Vascular Depression Hypothesis

OBJECTIVE

Studies have identified longitudinally that there exists an association between depression, cerebral blood flow (CBF), and white matter hyperintensities that are thought to be due to vascular pathologies in the brain. However, the changes in CBF, a measure that reflects cerebrovascular integrity, following pharmacotherapy are not well understood. In this study, we investigated the dynamic CBF changes over the course of antidepressant treatment and the association of these changes with depressive symptoms.

METHODS

We used pseudocontinuous arterial spin labeling to investigate CBF changes in a sample of older patients (≥ 50 years of age; N = 46; 29 female) with a DSM-IV diagnosis of major depressive disorder. Participants had 5 magnetic resonance imaging scans (at baseline, the day after receiving a placebo, the day after receiving a first dose of venlafaxine, a week after starting venlafaxine treatment, and at the end of trial [12 weeks]). Montgomery-Asberg Depression Rating Scale (MADRS) was used to evaluate depression severity and treatment outcome. We investigated the association between changes in depression severity with changes in voxel-wise CBF while adjusting for potential confounding factors.

RESULTS

Increased CBF in the middle and posterior cingulate between baseline and end of treatment was significantly associated with percent decrease in MADRS score, independent of sex and Mini-Mental State Examination score (5,000 permutations, cluster forming threshold P < .005, family-wise error P < .05). No significant effects were detected between baseline and other scans (ie, placebo, acute [single dose], or subacute [after a week]).

CONCLUSIONS

Regional CBF increases were associated with decreases in depressive symptoms. This observation is consistent with the vascular depression hypothesis in late-life depression.

TRIAL REGISTRATION

ClinicalTrials.gov identifiers: NCT00892047 and NCT01124188.

Differential effects of antidepressant treatment on long-range and short-range functional connectivity strength in patients with major depressive disorder

ABSTARCT

Although we have some basic understanding of the neurochemical mechanisms of the antidepressants, the network-level effect of antidepressant treatment is still not fully understood. This study was conducted to investigate the effects of antidepressant on functional brain networks of patients with major depressive disorder (MDD). We performed resting-state fMRI scans on 20 first-episode drug-naive MDD patients at baseline and after escitalopram medication for 8 weeks. Twenty healthy controls also received MRI scans with an 8-week interval. The graph theory indices, long- and short-range functional connectivity strength (FCS), were computed to characterize the brain connectivity. The analysis of covariance was conducted on FCS maps of patients and controls to obtain the interaction effect of group and time, which indicate treatment-related effect. Following treatment, increased long-range FCS in the bilateral posterior cingulate cortex/precuneus and right thalamus in MDD patients at baseline were reduced. Meanwhile, increased short-range FCS in the bilateral ventromedial prefrontal cortex and left amygdala in patients were reduced, while reduced short-range FCS in the right parahippocampal gyrus was increased. Results suggest that the brain regions associated with negative emotional processing and regulation, and self-referential function could be modulated by escitalopram treatment; long- and short-range FCS are differentially affected by antidepressant.

The serotonin transporter polymorphism (5-HTTLPR) and coping strategies influence successful emotion regulation in an acute stress situation: Physiological evidence

INTRODUCTION

Emotion regulation is an important everyday-life skill to reduce harm and stress. Consequently, research shows associations between psychopathologies and emotional dysregulation. The serotonin transporter polymorphism (5-HTTLPR) has repeatedly been associated to phenotypes and syndromes related to emotional dysregulation. However, there is no study showing any direct effects of 5-HTTLPR genotype and emotion regulation. Hence, the aim of the present study was to draw a link between 5-HTTLPR to emotion regulation.

METHOD

N=91 healthy participants filled in a coping questionnaire, provided gene samples and participated in an emotion regulation experiment. In a within-subject design they viewed emotional pictures and were either instructed to suppress their emotions or not. During the emotion regulation task, skin conductance responses (SCR) were recorded.

RESULTS

Emotion regulation abilities measured by SCR were influenced by 5-HTTLPR and coping strategies, together explaining 30% of variance. S-allele carriers showed increased SCRs when watching aversive stimuli in the uninstructed condition. However, when receiving an emotion regulation instruction, they were able to downregulate their arousal resulting in comparable SCRs as observed in LL-carriers.

DISCUSSION

This is the first study showing an impact of 5-HTTLPR on physiological emotion regulation. Results show that S-allele carriers have the same emotional arousal as L-allele carriers, when they get a supportive instruction to suppress unwanted feelings. These findings have implications for psychotherapeutic treatments.

Emotion Regulation: A Transdiagnostic Perspective on a New RDoC Domain

It is widely agreed that emotion regulation plays an important role in many psychological disorders. We make the case that emotion regulation is in fact a key transdiagnostic factor, using the Research Domain Criteria (RDoC) as an organizing framework. In particular, we first consider how transdiagnostic and RDoC approaches have extended categorical views. Next, we examine links among emotion generation, emotion regulation, and psychopathology, with particular attention to key emotion regulation stages including identification, strategy selection, implementation, and monitoring. We then propose that emotion regulation be viewed as a sixth domain in the RDoC matrix, and provide a brief overview of how the literature has used the RDoC units of analyses to study emotion regulation. Finally, we highlight opportunities for future research and make recommendations for assessing and treating psychopathology.

Impact of 5-HTTLPR on SSRI serotonin transporter blockade during emotion regulation: A preliminary fMRI study

BACKGROUND

The short ('S') allele of the serotonin transporter (5-HTT)-linked polymorphic region (5-HTTLPR) is associated with increased negative emotion processing bias, and this polymorphism moderates acute effects of selective serotonin reuptake inhibitor (SSRI) treatment. In this preliminary study, we explore the moderating effect of 5-HTTLPR on the impact of the SSRI, escitalopram during emotion regulation of negative emotional stimuli.

METHOD

Thirty-six healthy Caucasian, female participants underwent two fMRI scanning sessions following single dose escitalopram and placebo administration separated by a seven-day washout period according to a double-blind, randomized, placebo-controlled crossover design. Functional connectivity analysis was employed with a left (L) amygdala seed and a right interior frontal gyrus (R IFG) target.

RESULTS

Changes in functional connectivity with emotion regulation and treatment were linearly related to 5-HTTLPR 'L' allele load such that negative R IFG-L amygdala connectivity was increased with an increasing number of 'L' alleles. Therefore, escitalopram may facilitate the effects of reappraisal by enhancing negative functional connectivity, a finding that is greatest in participants homozygous for the 'L' allele and least in those homozygous for the 'S' allele.

LIMITATIONS

Sub-samples of the homozygote 'S/S' and 'L/L' 5-HTTLPR groupings were small. However, the within-subjects nature of the experiment and observing changes at the individual subject level increases our confidence in the findings of the present study.

CONCLUSIONS

The present study elucidates a potential neural mechanism by which antidepressant treatment produces differential treatment outcomes dependent on the 5-HTTLPR polymorphism, providing new and important leads for models of antidepressant action.

Mood disorders: neurocognitive models

OBJECTIVES

In recent years, a number of neurocognitive models stemming from psychiatry and psychology schools of thought have conceptualized the pathophysiology of mood disorders in terms of dysfunctional neural mechanisms that underpin and drive neurocognitive processes. Though these models have been useful for advancing our theoretical understanding and facilitating important lines of research, translation of these models and their application within the clinical arena have been limited-partly because of lack of integration and synthesis. Cognitive neuroscience provides a novel perspective for understanding and modeling mood disorders. This selective review of influential neurocognitive models develops an integrative approach that can serve as a template for future research and the development of a clinically meaningful framework for investigating, diagnosing, and treating mood disorders.

METHODS

A selective literature search was conducted using PubMed and PsychINFO to identify prominent neurobiological and neurocognitive models of mood disorders.

RESULTS

Most models identify similar neural networks and brain regions and neuropsychological processes in the neurocognition of mood, however, they differ in terms of specific functions attached to neural processes and how these interact. Furthermore, cognitive biases, reward processing and motivation, rumination, and mood stability, which play significant roles in the manner in which attention, appraisal, and response processes are deployed in mood disorders, are not sufficiently integrated. The inclusion of interactions between these additional components enhances our understanding of the etiology and pathophysiology of mood disorders.

CONCLUSIONS

Through integration of key cognitive functions and understanding of how these interface with neural functioning within neurocognitive models of mood disorders, a framework for research can be created for translation to diagnosis and treatment of mood disorders.