Increased neural sensitivity to self-relevant stimuli in major depressive disorder

Event-related potentials of social comparisons in depression and social anxiety

Social comparison is central in human life and can be especially challenging in depression and social anxiety. We assessed event-related potentials and emotions using a social comparison task in which participants received feedback on both their own and a co-player's performance, in participants with depression and/or social anxiety (n = 63) and healthy controls (n = 72). Participants reported more negative emotions for downward (being better than the co-player [participant correct, co-player wrong]) and upward (being worse than the co-player [participant wrong, co-player correct]) comparisons versus even outcomes, with these effects being stronger in depression and social anxiety. At the Medial Frontal Negativity, both controls and depressed participants showed a more negative amplitude for upward comparison versus both the participant and co-player performing wrong. Socially anxious subjects showed the opposite effect, possibly due to greater expectations about being worse than others. The P300 decreased for downward and upward comparisons compared to even outcomes, which may relate to the higher levels of conflict of social inequality. Depressed and socially anxious subjects showed a blunted P300 increase over time in response to the task outcomes, suggesting deficits in allocating resources for the attention of incoming social information. The LPP showed increased amplitude for downward and upward comparison versus the even outcomes and no group effect. Emotional findings suggest that social comparisons are more difficult for depressed and socially anxious individuals. Event-related potentials findings may shed light on the neural substrates of these difficulties.

Concreteness ratings for 36,000 Estonian words

We present a collection of concreteness ratings for 35,979 words in Estonian. The data were collected via a web application from 2278 native Estonian speakers. Human ratings of concreteness have not been collected for Estonian beforehand. We compare our results to Aedmaa et al. (2018), who assigned concreteness ratings to 240,000 Estonian words by means of machine learning. We show that while these two datasets show reasonable correlation (R = 0.71), there are considerable differences in the distribution of the ratings, which we discuss in this paper. Furthermore, the results also raise questions about the importance of the type of scale used for collecting ratings. While most other datasets have been compiled based on questionnaires entailing five- or seven-point Likert scales, we used a continuous 0-10 scale. Comparing our rating distribution to those of other studies, we found that it is most similar to the distribution in Lahl et al. (Behavior Research Methods, 41(1), 13-19, 2009), who also used a 0-10 scale. Concreteness ratings for Estonian words are available at OSF .

Reduced generalization of reward among individuals with subthreshold depression: Behavioral and EEG evidence

Altered stimulus generalization has been well-documented in anxiety disorders; however, there is a paucity of research investigating this phenomenon in the context of depression. Depression is characterized by impaired reward processing and heightened attention to negative stimuli. It is hypothesized that individuals with depression exhibit reduced generalization of reward stimuli and enhanced generalization of loss stimuli. Nevertheless, no study has examined this process and its underlying neural mechanisms. In the present study, we recruited 25 participants with subthreshold depression (SD group) and 24 age-matched healthy controls (HC group). Participants completed an acquisition task, in which they learned to associate three distinct pure tones (conditioned stimuli, CSs) with a reward, a loss, or no outcome. Subsequently, a generalization session was conducted, during which similar tones (generalization stimuli, GSs) were presented, and participants were required to classify them as a reward tone, a loss tone, or neither. The results revealed that the SD group exhibited reduced generalization errors in the early phase of generalization, suggesting a diminished ability to generalize reward-related stimuli. The event-related potential (ERP) results indicated that the SD group exhibited decreased generalization of positive valence to reward-related GSs and heightened generalization of negative valence to loss-related GSs, as reflected by the N1 and P2 components. However, the late positive potential (LPP) was not modulated by depression in reward generalization or loss generalization. These findings suggested that individuals with subthreshold depression may have a blunted or reduced ability to generalize reward stimuli, shedding light on potential treatment strategies targeting this particular process.

Acute high-intensity interval exercise improves food-related cognition in young adults with obesity: An ERP study

Purpose Cognitive function, particularly food-related cognition, is critical for maintaining a healthy weight and preventing the acceleration of obesity. High-Intensity Interval Exercise (HIIE) is an increasingly popular form of exercise and has been shown to improve physical fitness and cognitive function. However, there is limited research on the effects and underlying mechanisms of HIIE on general and food-related cognition among adults with obesity. The aim of the current study was to examine the influence of a single bout of HIIE on food-related cognition among young adults with obesity. Methods Fifteen young men with obesity (BMI = 33.88 ± 4.22, age = 24.60 ± 5.29 years) were recruited. Participants took part in a HIIE condition consisting of 30 minutes of stationary cycle exercise (5-min warm-up, 20-min HIIE and 5-min cool down), and a control session consisting of a time and attention-matched period of sedentary rest in a counterbalanced order. Behavioral (reaction time and accuracy) and event-related potential measures (P3 and the late positive potential, LPP) elicited during a food-related Flanker task were measured after the HIIE and control session. Results Shorter response times were observed following HIIE, regardless of congruency or picture type, with no change in accuracy. Increased P3 and LPP amplitudes were observed following HIIE relative to the control session. Conclusion The findings suggest a single bout of HIIE has a beneficial effect on general and food-related cognition among young adults with obesity, with increased recruitment of cognitive resources to support cognitive control. Future research is warranted to examine the dose-response relationship between acute bouts or longer participation in HIIE on food-related cognition in obesity.

Characterizing positive and negative valence systems function in adolescent depression: An RDoC-informed approach integrating multiple neural measures

Depression is a prevalent, debilitating, and costly disorder that often manifests in adolescence. There is an urgent need to understand core pathophysiological processes for depression to inform more targeted intervention efforts. The Research Domain Criteria (RDoC) Positive Valence Systems (PVS) and Negative Valence Systems (NVS) have both been implicated in depression symptomatology and vulnerability; however, the nature of NVS alterations is unclear across studies, and associations between single neural measures and symptoms are often small in magnitude and inconsistent. The present study advances characterization of depression in adolescence via an innovative data-driven approach to identifying subgroups of PVS and NVS function by integrating multiple neural measures (assessed by electroencephalogram [EEG]) relevant to depression in adolescents oversampled for clinical depression and depression risk based on maternal history (N = 129; 14-17 years old). Results of the k-means cluster analysis supported a two-cluster solution wherein one cluster was characterized by relatively attenuated reward and emotion responsiveness across valences and the other by relatively intact responsiveness. Youth in the attenuated responsiveness cluster reported significantly greater depressive symptoms and were more likely to have major depressive disorder diagnoses than youth in the intact responsiveness cluster. In contrast, associations of individual neural measures with depressive symptoms were non-significant. The present study highlights the importance of innovative neuroscience approaches to characterize emotional processing in depression across domains, which is imperative to advancing the clinical utility of RDoC-informed research.

Effectiveness of memory bias modification in reducing depression and rumination symptoms and autobiographical memory bias: a pilot study

There is a strong interest in cognitive bias modification as a new intervention that targets key underlying vulnerability factors of depression. Memory bias is believed to be a risk factor for the onset and maintenance of depression. In this study, we aimed to examine the effectiveness of memory bias modification on depression symptoms, ruminative thoughts, and autobiographical memory bias. We recruited 40 participants with mild depression who were randomly assigned to two groups of positive (n = 20) and neutral (n = 20) training. The participants were instructed to read and learn French-paired words with their Farsi translations. Next, they were encouraged to recall positive or neutral Farsi translations of French words according to their groups in the first session. After training, and in the second session (follow-up), they were asked to recall all the Farsi translations of the French words. Data were collected using Beck Depression Inventory II (BDI-II), Rumination Response Scale (RRS), Self-Referent Encoding Task (SRET). Analysis of covariance (ANCOVA) and logistic regression were used to analyze the data. Repeated retrieval practices resulted in better recall of the target words of the training in both conditions. Still, none of the groups had significant changes in depression scores, ruminative thoughts, and emotional aspects of memory bias. Our results suggest that two sessions of modifying memory biases were not sufficient for reducing the symptoms of depression and rumination. Implications of the finding from this study for future works are further discussed.

Self-Relevance Moderates the Relationship between Depressive Symptoms and Corrugator Activity during the Imagination of Personal Episodic Events

Accumulating evidence suggests depression is associated with blunted reactivity to positive and negative stimuli, known as emotion context insensitivity (ECI). However, ECI is not consistently observed in the literature, suggesting moderators that influence its presence. We propose self-relevance as one such moderator, with ECI most apparent when self-relevance is low. We examined this proposal by measuring self-report and facial electromyography (EMG) from the corrugator muscle while participants (n = 81) imagined hypothetical scenarios with varying self-relevance and recalled autobiographical memories. Increased depressive symptoms on the Center for Epidemiologic Studies Depression Scale were associated with less differentiated arousal and self-relevance ratings between happy, neutral, and sad scenarios. EMG analyses further revealed that individuals with high depressive symptoms exhibited blunted corrugator reactivity (reduced differentiation) for sad, neutral, and happy scenarios with low self-relevance, while corrugator reactivity remained sensitive to valence for highly self-relevant scenarios. By comparison, in individuals with low depressive symptoms, corrugator activity differentiated valence regardless of stimulus self-relevance. Supporting a role for self-relevance in shaping ECI, we observed no depression-related differences in emotional reactivity when participants recalled highly self-relevant happy or sad autobiographical memories. Our findings suggest ECI is primarily associated with blunted reactivity towards material deemed low in self-relevance.

Brain State Relays Self-Processing and Heartbeat-Evoked Cortical Responses

The self has been proposed to be grounded in interoceptive processing, with heartbeat-evoked cortical activity as a neurophysiological marker of this processing. However, inconsistent findings have been reported on the relationship between heartbeat-evoked cortical responses and self-processing (including exteroceptive- and mental-self-processing). In this review, we examine previous research on the association between self-processing and heartbeat-evoked cortical responses and highlight the divergent temporal-spatial characteristics and brain regions involved. We propose that the brain state relays the interaction between self-processing and heartbeat-evoked cortical responses and thus accounts for the inconsistency. The brain state, spontaneous brain activity which highly and continuously changes in a nonrandom way, serves as the foundation upon which the brain functions and was proposed as a point in an extremely high-dimensional space. To elucidate our assumption, we provide reviews on the interactions between dimensions of brain state with both self-processing and heartbeat-evoked cortical responses. These interactions suggest the relay of self-processing and heartbeat-evoked cortical responses by brain state. Finally, we discuss possible approaches to investigate whether and how the brain state impacts the self-heart interaction.

Familial risk for depression is associated with reduced P300 and late positive potential to affective stimuli and prolonged cardiac deceleration to unpleasant stimuli

Despite evidence of abnormal affective processing as a key correlate of depression, specific attentional mechanisms underlying processing of emotions in familial risk for depression have yet to be investigated in a single study. To this end, the amplitude of the P300 and late positive potential (LPP) complex and cardiac deceleration were assessed during the passive viewing of affective pictures in 32 individuals who had family history of depression (without depressive symptoms) and in 30 controls (without depressive symptoms and family history of depression). Individuals with familial risk for depression revealed reduced P300-LPP amplitudes in response to pleasant and unpleasant stimuli relative to controls, and comparable P300-LPP amplitudes in response to pleasant and neutral stimuli. Controls, but not individuals with familial risk for depression, reported cardiac deceleration during the viewing of pleasant vs. neutral and unpleasant stimuli in the 0-3 s time window. Also, only individuals with familial risk for depression showed a prolonged cardiac deceleration in response to unpleasant vs. neutral stimuli. Overall, the present study provides new insights into the characterization of emotion-related attentional processes in familial risk for depression as potential vulnerability factors for the development of the disorder.

Electrophysiological evidence for the characteristics of implicit self-schema and other-schema in patients with major depressive disorder: An event-related potential study

Background

The significance of implicit self-schema and other-schema in major depressive disorder (MDD) is highlighted by both cognitive theory and attachment theory. The purpose of the current study was to investigate the behavioral and event-related potential (ERP) characteristics of implicit schemas in MDD patients.

Methods

The current study recruited 40 patients with MDD and 33 healthy controls (HCs). The participants were screened for mental disorders using the Mini-International Neuropsychiatric Interview. Hamilton Depression Rating Scale-17 and Hamilton Anxiety Rating Scale-14 were employed to assess the clinical symptoms. Extrinsic Affective Simon Task (EAST) was conducted to measure the characteristics of implicit schemas. Meanwhile, reaction time and electroencephalogram data were recorded.

Results

Behavioral indexes showed that HCs responded faster to positive self and positive others than negative self (t = -3.304, p = 0.002, Cohen's d = 0.575) and negative others (t = -3.155, p = 0.003, Cohen's d = 0.549), respectively. However, MDD did not show this pattern (p > 0.05). The difference in other-EAST effect between HCs and MDD was significant (t = 2.937, p = 0.004, Cohen's d = 0.691). The ERP indicators of self-schema showed that under the condition of positive self, the mean amplitude of LPP in MDD was significantly smaller than that in HCs (t = -2.180, p = 0.034, Cohen's d = 0.902). The ERP indexes of other-schema showed that HCs had a larger absolute value of N200 peak amplitude for negative others (t = 2.950, p = 0.005, Cohen's d = 0.584) and a larger P300 peak amplitude for positive others (t = 2.185, p = 0.033, Cohen's d = 0.433). The above patterns were not shown in MDD (p > 0.05). The comparison between groups found that under the condition of negative others, the absolute value of N200 peak amplitude in HCs was larger than that in MDD (t = 2.833, p = 0.006, Cohen's d = 1.404); under the condition of positive others, the P300 peak amplitude (t = -2.906, p = 0.005, Cohen's d = 1.602) and LPP amplitude (t = -2.367, p = 0.022, Cohen's d = 1.100) in MDD were smaller than that in HCs.

Conclusion

Patients with MDD lack positive self-schema and positive other-schema. Implicit other-schema might be related to abnormalities in both the early automatic processing stage and the late elaborate processing stage, while the implicit self-schema might be related only to the abnormality in the late elaborate processing stage.

Emotion Context Insensitivity is generalized in individuals with major depressive disorder but not in those with subclinical depression

BACKGROUND

Depressed individuals experience deficits in emotional reactivity. One well-established theory is the Emotion Context Insensitivity (ECI) theory. To better understand impairments in emotional reactivity, we investigated whether the ECI theory is applicable to anticipatory, consummatory, and remembered affect, in both clinical and subclinical depression.

METHODS

Participants were divided into four groups: Major Depressive Disorder Group (MDD, N = 60), Control Group for MDD (Control_MDD, N = 50), Subclinical Depression Group (SD, N = 56), and Control Group for SD (Control_SD, N = 56). The Hamilton Depression Rating Scale and the Beck Depression Inventory were used to assess the severity of depression and anhedonia symptoms. The Monetary Incentive Delay Task evaluated participants' affective responses towards monetary stimuli.

RESULTS

The MDD group was more insensitive to both monetary reward and loss across most types of affect than was the control group. Compared with the controls, the SD group exhibited lower reactivity in anticipatory positive affect but enhanced reactivity in consummatory positive, anticipatory, and remembered negative affect.

LIMITATIONS

Emotional affect was evaluated by subjective ratings, which may lack objectivity. Additionally, laboratory settings and monetary rewards used in this study may cause the results less generalized to daily life and to other types of rewards.

CONCLUSION

The pattern of emotional reactivity in the MDD group was partly consistent with the ECI theory, whereas the SD group showed greater arousal and instability of emotional reactions. These different patterns could facilitate the understanding of emotional reactivity and develop further treatments across the course of depression.

Aberrant social feedback processing and its impact on memory, social evaluation, and decision-making among individuals with depressive symptoms

BACKGROUND

Depression is associated with aberrant social feedback processing. However, little is known about the impact of these deficits on individuals' memory, social evaluation, and social decision-making.

METHODS

We examined event-related potentials (ERPs) during the processing of social feedback with different emotional valences and intensities, among individuals with high and low depressive symptoms. After three days, participants performed a recall test, along with social evaluation and money allocation.

RESULTS

Compared with the control group, participants with depressive symptoms showed larger occipital P1 and parietal P3 amplitudes to negative social feedback, as well as larger frontal feedback-related negativity toward highly positive social feedback; this indicates toward altered attentional allocation, encoding, and anticipation in social feedback processing. After three days of social feedback processing, individuals in the depressive symptom group recalled negative social feedback better and gave less positive evaluations and allocated less money to the senders of highly negative social feedback compared with control group participants. Notably, ERPs predicted subsequent memory, social evaluation, and decision-making, suggesting a significant impact of aberrant social feedback processing on social cognition and behaviors in depression.

LIMITATIONS

Individuals with depressive symptoms rather than patients with depressive disorders were recruited and therefore caution is needed in applying the findings to clinical populations.

CONCLUSIONS

Individuals with depressive symptoms exhibit negative bias in anticipation, attentional allocation, and encoding processes during social feedback processing, which further influences their memory, social evaluation, and social decision-making in the long run. These aberrant biases should be targeted to prevent the development of major depressive disorders.

No Self Without Salience: Affective and Self-relevance Ratings of 552 Emotionally Valenced and Neutral Dutch Words

It is unknown how self-relevance is dependent on emotional salience. Emotional salience encompasses an individual's degree of attraction or aversion to emotionally-valenced information. The current study investigated the interconnection between self and salience through the evaluation of emotional valence and self-relevance. 56 native Dutch participants completed a questionnaire assessing valence, intensity, and self-relevance of 552 Dutch nouns and verbs. One-way repeated-measures ANCOVA investigated the relationship between valence and self, age and gender. Repeated-measures ANCOVA also tested the relationship between valence and self with intensity ratings and effects of gender and age. Results showed a significant main effect of valence for self-relevant words. Intensity analyses showed a main effect of valence but not of self-relevance. There were no significant effects of gender and age. The most important finding presents that self-relevance is dependent on valence. These findings concerning the relationship between self and salience opens avenues to study an individual's self-definition.

The Neural Correlates of the Abnormal Implicit Self-Esteem in Major Depressive Disorder: An Event-Related Potential Study

Implicit self-esteem (ISE) has been considered a critical factor in the development and maintenance of major depressive disorder (MDD). Further investigating the event-related potential (ERP) characteristics underlying abnormal ISE in MDD would be helpful for understanding the neural mechanism of MDD. For this purpose, 32 MDD patients and 31 age- and sex-matched healthy controls (HCs) were enrolled in this study. The Rosenberg Self-Esteem Scale (RSES) was used to evaluate explicit self-esteem (ESE), and a self-esteem go/no-go association task (GNAT) was used to assess ISE. Electroencephalograms were synchronously recorded when performing the self-esteem GNAT. Behavioral data and ERP characteristics under different conditions were analyzed and compared within and across groups. The results showed that compared to HCs, MDD patients had significantly lower RSES scores and self-D scores of GNAT, which reflected lower levels of ESE and ISE, respectively. No significant correlation was found between RESE and self-D scores, and only RESE scores were significantly negatively correlated with the Hamilton Depression Rating Scale (HAMD) score. The averaged centroparietal go-P3 amplitude under the self-positive condition was significantly smaller in MDD than in HCs. Moreover, HCs had a significantly larger average centroparietal go-P3 amplitude in self-positive than in self-negative conditions, while this pattern was opposite in the MDD group. The neural activity patterns for other conditions were similar between MDD and HCs. Our results suggested that patients with MDD have a decreased level of both ESE and ISE, and ISE might be more independent of clinical symptoms. Decreased neural processing that implicitly associate self with positive conditions (and relatively increased implicit association between self and negative conditions) might be important neural correlates for abnormal ISE in MDD.

The neural correlates of interference control dysfunction of working memory in major depressive disorder: An event-related potential study

Interference control function is a key function in a series of specific functions of working memory (WM), which is usually impaired in patients with major depressive disorder (MDD). Event-related potentials (ERPs) have advantages in exploring the neural processing of interference control and WM impairment, and therefore, it is helpful to further understand the neural mechanism of MDD. In the present study, 44 patients with MDD and 44 age- and sex-matched healthy controls (HCs) were recruited. All participants completed a 4-gradient difficulty Brown-Peterson task (BPT), whose difficulty was manipulated by changing the demand of interspersed distraction tasks. High-density EEG was simultaneously recorded. The hit rate and reaction time (RT) toward the target stimulus as well as the underlying ERP features were analyzed. The results showed that, when compared with HCs, MDD patients had significantly lower hit rates and longer RTs among all four difficulties of BPT. For ERP components, no significant between-group difference was found in either N100 or P200 average amplitudes; however, the centroparietal late positive potential (LPP) amplitude of both MDD group and HC group decreased with the increase of BPT difficulty, despite the pattern of the HC group was relative moderate. For both groups, the LPP amplitude was significantly smaller in high-order difficult BPT tasks than in low-order difficult tasks. Moreover, LPP amplitude in high-order difficult tasks was much smaller in MDD group than that of HC group. Our findings suggest that failure to control interference well may play a critical role in the impairment of WM in patients with MDD, and provided new evidence that the neural correlates of interference control dysfunction of WM in MDD.

Disentangling emotional processing in dysphoria: An ERP and cardiac deceleration study

The present study aimed to investigate emotional processing in dysphoria. To this end, the amplitude of the Late Positive Potential (LPP) and cardiac deceleration were assessed during the passive viewing of affective (pleasant, neutral, and unpleasant) pictures in 26 individuals with dysphoria and in 25 non-depressed controls. The group with dysphoria revealed a smaller LPP amplitude than the group without dysphoria in response to pleasant and neutral, but not unpleasant, stimuli at centro-parieto-occipital sites. Interestingly, whereas both groups showed cardiac deceleration when viewing pleasant compared to neutral pictures (3-6 s time window), only individuals with dysphoria showed a prolonged cardiac deceleration in response to unpleasant stimuli as compared with neutral ones. This study suggests that dysphoria is characterized by reduced motivated attentional allocation to positive information and by sustained intake of unpleasant information. Overall, the present findings provide novel insights into the characterization of valence-specific attentional processes in dysphoria as potential vulnerability factors for clinically significant depression.

Depressive rumination is correlated with brain responses during self-related processing

BACKGROUND

Rumination, a tendency to focus on negative self-related thoughts, is a central symptom of depression. Studying the self-related aspect of such symptoms is challenging because of the need to distinguish self effects from the emotional content of task stimuli. This study employed an emotionally neutral self-related paradigm to investigate possible altered self-processing in depression and its link to rumination.

METHODS

People with major depressive disorder (n = 25) and controls (n = 25) underwent task-based electro-encephalogram recording. We studied late event-related potentials, along with low-frequency oscillatory power. We compared electroencephalogram metrics between groups and correlated them with depressive symptoms and reported rumination.

RESULTS

Participants with major depressive disorder displayed a difference in late positive potentials across frontocentral electrodes between self-related and non-self-related conditions. We found no such difference in controls. The magnitude of this difference was positively correlated with depressive symptoms and reported rumination. Participants with major depressive disorder also had elevated theta oscillation power at central electrodes in self-related conditions, a finding that we did not see in controls.

LIMITATIONS

Patients with major depressive disorder were medicated at the time of the study. The group studied was primarily female, so the observed effects may have been sex-specific.

CONCLUSION

Rumination appears to be linked to altered self-related processing in depression, independent of stimuli-related emotional confounds. This connection between self-related processing and depression may point to a self disorder as a core component of depression.

Neurophysiological Responses to Interpersonal Emotional Images: Associations with Symptoms of Depression and Social Anxiety

Affective neuroscience research using electrocortical event-related potentials has provided valuable insights on alterations in emotion processing in internalizing disorders. However, internalizing disorders are accompanied by additional impairments in social cognition and functioning, and most extant research examines neural responses to broad categories of emotional scenes or faces presented irrespective of context. Examining neural reactivity specifically to interpersonal emotional scenes may more precisely capture and disentangle processes involved in depression and social anxiety, two highly comorbid forms of psychopathology. The current study validated a novel set of positive and threatening interpersonal emotional stimuli in a sample of emerging adults (N = 114) who completed a modified emotional interrupt paradigm while electroencephalogram and behavioral data were recorded. Participant ratings of valence and arousal supported the validity of the emotional images. Consistent with prior research, sustained neurophysiological processing indexed by the late positive potential (LPP) was observed for interpersonal emotional images, especially positive, compared with neutral images. Elevated LPP reactivity to both positive and threatening interpersonal images moderated the effects of chronic interpersonal stress on social anxiety symptoms, such that enhanced LPP reactivity in conjunction with higher levels of chronic interpersonal stress was associated with elevated social anxiety symptoms. These results were unique to social anxiety symptoms and not symptoms of depression, suggesting sustained neural processing of interpersonal stimuli may differentiate social anxiety from depression. Future research on emotional reactivity specifically within the interpersonal domain is needed to inform our understanding of developmental pathways to internalizing psychopathology.

Comorbid anxiety and depression: Opposing effects on the electrocortical processing of negative imagery in a focal fear sample

BACKGROUND

Anxiety and depression are highly comorbid and share clinical characteristics, such as high levels of negative emotion. Attention toward negative stimuli in anxiety and depression has been studied primarily using negative pictures. Yet, negative mental imagery-that is, mental representations of imagined negative events or stimuli-might more closely mirror patient experience.

METHODS

The current study presents the first examination of neural response to negative imagery in 57 adults (39 female) who all shared a common "focal fear" diagnosis (i.e., specific phobia or performance-only social anxiety disorder), but varied in levels of comorbid anxiety and depression. After listening to standardized descriptions of negative and neutral scenes, participants imagined these scenes as vividly as possible. Associations between categorical and continuous measures of depression, generalized anxiety disorder (GAD), and social anxiety disorder with electrocortical and subjective responses to negative imagery were assessed.

RESULTS

Individuals who were more depressed showed reduced electrocortical processing of negative imagery, whereas those with GAD showed increased electrocortical processing of negative imagery-but only when controlling for depression. Furthermore, participants with higher levels of depression rated negative imagery as less negative and those with greater social anxiety symptoms rated negative imagery more negatively.

CONCLUSIONS

Depression and GAD are characterized by opposing electrocortical response to negative imagery; moreover, depression may suppress GAD-related increases in the electrocortical processing of negative imagery. Results highlight distinctions between different dimensions of distress-based psychopathology, and reveal the unique and complex contribution of comorbid depression to affective response in anxiety.

Emotion context insensitivity in depression: Toward an integrated and contextualized approach

Major depressive disorder (MDD) is characterized by pervasive mood disturbance as well as deficits in emotional processing, reactivity, and regulation. There is accumulating evidence that MDD is characterized by emotional patterns consistent with environmental disengagement, as reflected in attenuated positive and negative emotional reactivity, consistent with Emotion Context Insensitivity (ECI) theory. However, MDD individuals vary considerably in the extent to which they exhibit specific alterations in patterns of emotional responding. Emotions are complex, multicomponent processes that invoke responses across multiple functional domains and levels of analysis, including subjective experience, behavior, autonomic regulation, cognition, and neural processing. In this article, I review the current state of the literature on emotional responding and MDD from the lens of ECI. I focus on the importance of assessing emotional indices from multiple levels of analysis across development and contexts. I also discuss methodological and measurement issues that may contribute to inconsistent findings. In particular, I emphasize how psychophysiological measures can help elucidate emotional processes that underlie the pathophysiology of MDD as part of an integrated and contextualized approach.

Psychological mechanisms and functions of 5-HT and SSRIs in potential therapeutic change: Lessons from the serotonergic modulation of action selection, learning, affect, and social cognition

Uncertainty regarding which psychological mechanisms are fundamental in mediating SSRI treatment outcomes and wide-ranging variability in their efficacy has raised more questions than it has solved. Since subjective mood states are an abstract scientific construct, only available through self-report in humans, and likely involving input from multiple top-down and bottom-up signals, it has been difficult to model at what level SSRIs interact with this process. Converging translational evidence indicates a role for serotonin in modulating context-dependent parameters of action selection, affect, and social cognition; and concurrently supporting learning mechanisms, which promote adaptability and behavioural flexibility. We examine the theoretical basis, ecological validity, and interaction of these constructs and how they may or may not exert a clinical benefit. Specifically, we bridge crucial gaps between disparate lines of research, particularly findings from animal models and human clinical trials, which often seem to present irreconcilable differences. In determining how SSRIs exert their effects, our approach examines the endogenous functions of 5-HT neurons, how 5-HT manipulations affect behaviour in different contexts, and how their therapeutic effects may be exerted in humans - which may illuminate issues of translational models, hierarchical mechanisms, idiographic variables, and social cognition.

Negative memory bias as a transdiagnostic cognitive marker for depression symptom severity

BACKGROUND

Negative memory bias is a strong risk factor for the development and maintenance of depression. Recent evidence also found negative memory bias in other mental disorders. Here, we aim to: 1) assess the presence and strength of negative memory bias in a range of (comorbid) mental disorders, 2) investigate which disorder-specific symptoms are associated with negative memory bias, and 3) test whether negative memory bias might be a transdiagnostic mechanism.

METHODS

Negative memory bias was measured in patients with at least one diagnosis of a stress-related disorder (n = 86), a neurodevelopmental disorder (n = 53), or both (n = 68), and 51 controls. Depression, anxiety, attention-deficit/hyperactivity disorder, and autism spectrum disorder symptom severity was assessed using questionnaires. Groups were compared on negative memory bias and the associations between negative memory bias and symptom severity were made using linear regression models.

RESULTS

All patient groups showed stronger negative memory bias than the controls. Negative memory bias was individually associated with all symptom severity indices, but when added into a single model, only the association with depressive symptom severity remained. This persisted after controlling for diagnostic group.

LIMITATIONS

Due to the cross-sectional sectional study design, we could only look at the associations between negative memory bias and disorder-specific symptoms and not at the direction of the effects.

CONCLUSIONS

Negative memory bias is characteristic of a depressotypic processing style and present in different mental disorders. It might play a mechanistic role in the development of (subclinical) co-occurrence between mental disorders.