Co-occurring anxiety influences patterns of brain activity in depression

Brain activation associated with anhedonic depression and co-occurring anxious arousal and anxious apprehension was measured by fMRI during performance of an emotion word Stroop task. Consistent with EEG findings, depression was associated with rightward frontal lateralization in the dorsolateral prefrontal cortex (DLPFC), but only when anxious arousal was elevated and anxious apprehension was low. Activity in the right inferior frontal gyrus (IFG) was also reduced for depression under the same conditions. In contrast, depression was associated with more activity in the anterior cingulate cortex (dorsal ACC and rostral ACC) and the bilateral amygdala. Results imply that depression, particularly when accompanied by anxious arousal, may result in a failure to implement top-down processing by appropriate brain regions (left DLPFC, right IFG) due to increased activation in regions associated with responding to emotionally salient information (right DLPFC, amygdala).     

Frontal brain asymmetry in depression with comorbid anxiety: a neuropsychological investigation

The approach-withdrawal model posits that depression and anxiety are associated with a relative right asymmetry in frontal brain activity. Most studies have tested this model using measures of cortical brain activity such as electroencephalography. However, neuropsychological tasks that differentially use left versus right frontal cortical regions can also be used to test hypotheses from the model. In two independent samples (Study 1 and 2), the present study investigated the performance of currently depressed individuals with or without a comorbid anxiety disorder and healthy controls on neuropsychological tasks tapping primarily left (verbal fluency) or right (design fluency) frontal brain regions. Across both samples, results indicated that comorbid participants performed more poorly than depressed only and control participants on design fluency, while all groups showed equivalent performance on verbal fluency. Moreover, comorbid participants showed "asymmetrical" performance on these two tasks (i.e., poorer design [right frontal] relative to verbal [left frontal] fluency), whereas depressed only and control participants showed approximately symmetrical profiles of performance. Results from these two samples suggest an abnormal frontal asymmetry in neurocognitive performance driven primarily by right frontal dysfunction among anxious-depressed individuals and highlight the importance of considering comorbid anxiety when examining frontal brain functioning in depression.     

Anger style, psychopathology, and regional brain activity

Depression and anxiety often involve high levels of trait anger and disturbances in anger expression. Reported anger experience and outward anger expression have recently been associated with left-biased asymmetry of frontal cortical activity, assumed to reflect approach motivation. However, different styles of anger expression could presumably involve different brain mechanisms and/or interact with psychopathology to produce various patterns of brain asymmetry. The present study explored these issues by comparing resting regional electroencephalographic activity in participants high in trait anger who differed in anger expression style (high anger-in, high anger-out, both) and participants low in trait anger, with depression and anxiety systematically assessed. Trait anger, not anger-in or anger-out, predicted left-biased asymmetry at medial frontal EEG sites. The anger-in group reported higher levels of anxious apprehension than did the anger-out group. Furthermore, anxious apprehension moderated the relationship between trait anger, anger-in, and asymmetry in favor of the left hemisphere. Results suggest that motivational direction is not always the driving force behind the relationship of anger and left frontal asymmetry. Findings also support a distinction between anxious apprehension and anxious arousal.     

Hemispheric lateralization of the EEG during wakefulness and REM sleep in young healthy adults

EEG recordings confirm hemispheric lateralization of brain activity during cognitive tasks. The aim of the present study was to investigate spontaneous EEG lateralization under two conditions, waking and REM sleep. Bilateral monopolar EEG was recorded in eight participants using a 12-electrode montage, before the night (5 min eyes closed) and during REM sleep. Spectral analysis (0.75-19.75 Hz) revealed left prefrontal lateralization on total spectrum amplitude power and right occipital lateralization in Delta activity during waking. In contrast, during REM sleep, right frontal lateralization in Theta and Beta activities and right lateralization in occipital Delta activity was observed. These results suggest that spontaneous EEG activities generated during waking and REM sleep are supported in part by a common thalamo-cortical neural network (right occipital Delta dominance) while additional, possibly neuro-cognitive factors modulate waking left prefrontal dominance and REM sleep right frontal dominance.     

Emotional valence and arousal interact in attentional control

ABSTRACT— A recent study demonstrated that observers' ability to identify targets in a rapid visual sequence was enhanced when they simultaneously listened to happy music. In the study reported here, we examined how the emotion-attention relationship is influenced by changes in both mood valence (negative vs. positive) and arousal (low vs. high). We used a standard induction procedure to generate calm, happy, sad, and anxious moods in participants. Results for an attentional blink task showed no differences in first-target accuracy, but second-target accuracy was highest for participants with low arousal and negative affect (sad), lowest for those with strong arousal and negative affect (anxious), and intermediate for those with positive affect regardless of their arousal (calm, happy). We discuss implications of this valence-arousal interaction for the control of visual attention.     

Electroencephalographic asymmetries in adolescents with major depression: influence of comorbidity with anxiety disorders

This study examined whether adolescents with major depressive disorder (MDD) display the abnormal electroencephalographic (EEG) alpha asymmetries found in depressed adults. Resting EEG was recorded in 25 right-handed female outpatients (19 with MDD, 11 of whom also had a current anxiety disorder; 6 with anxiety disorders only) and 10 non-ill controls. In contrast to the non-ill controls, adolescents having MDD but no anxiety disorder showed alpha asymmetry indicative of less activation over right than over left posterior sites. Within the MDD patient group, comorbid anxiety disorders reduced the posterior alpha asymmetry, supporting the potential importance of evaluating anxiety in studies of regional brain activation in adolescent MDD. These preliminary findings are similar to those from adult studies that suggest that MDD is associated with right parietotemporal hypoactivation.     

Speech presentation cues moderate frontal EEG asymmetry in socially withdrawn young adults

Socially withdrawn individuals display solitary behavior across wide contexts with both unfamiliar and familiar peers. This tendency to withdraw may be driven by either past or anticipated negative social encounters. In addition, socially withdrawn individuals often exhibit right frontal electroencephalogram (EEG) asymmetry at baseline and when under stress. In the current study we examined shifts in frontal EEG activity in young adults (N=41) at baseline, as they viewed either an anxiety-provoking or a benign speech video, and as they subsequently prepared for their own speech. Results indicated that right frontal EEG activity increased, relative to the left, only for socially withdrawn participants exposed to the anxious video. These results suggest that contextual affective cues may prime an individual's response to stress, particularly if they illustrate or substantiate an anticipated negative event.     

Temporal patterns of anxious and depressed mood in generalized anxiety disorder: a daily diary study

Research suggests that anxiety disorders tend to temporally precede depressive disorders, a finding potentially relevant to understanding comorbidity. The current study used diary methods to determine whether daily anxious mood also temporally precedes daily depressed mood. 55 participants with generalized anxiety disorder (GAD) and history of depressive symptoms completed a 21-day daily diary tracking anxious and depressed mood. Daily anxious and depressed moods were concurrently associated. Daily anxious mood predicted later depressed mood at a variety of time lags, with significance peaking at a two-day lag. Depressed mood generally did not predict later anxious mood. Results suggest that the temporal antecedence of anxiety over depression extends to daily symptoms in GAD. Implications for the refinement of comorbidity models, including causal theories, are discussed.     

Withdrawn and intrusive maternal interaction style and infant frontal EEG asymmetry shifts in infants of depressed and non-depressed mothers

The effects of maternal interaction style (intrusive/withdrawn) on the development of brain electrical activity were studied in infants of depressed and non-depressed mothers shortly after birth and again at 3-6 months of age. Infants of depressed mothers exhibited significantly greater relative right frontal EEG activation than infants of non-depressed mothers. Infants of depressed withdrawn mothers exhibited greater relative right frontal EEG activation than infants of depressed intrusive mothers. Furthermore, while infants of depressed mothers with intrusive interaction styles showed a shift towards greater relative left frontal EEG activation from birth to 3-6 months, infants of depressed mothers with withdrawn interaction styles showed a shift towards greater relative right frontal EEG activation.     

Regional brain electrical activity in posttraumatic stress disorder after motor vehicle accident

This study examined whether patients with posttraumatic stress disorder (PTSD) related to motor vehicle accidents (MVAs) would show an abnormal pattern of electroencephalographic (EEG) alpha asymmetries, which has been proposed for particular types of anxiety. Patients with PTSD (n = 22) or subsyndromal PTSD (n = 21), traumatized controls without PTSD (non-PTSD with MVA; n = 21), and healthy controls without MVA (n = 23) underwent measurement of EEG activity during baseline and exposure to a neutral, a positive, a negative, and an accident-related picture. Differences in brain asymmetry between groups were observed only during exposure to trauma-related material. PTSD and subsyndromal PTSD patients showed a pattern of enhanced right anterior and posterior activation, whereas non-PTSD with MVA participants showed the opposite pattern. Furthermore, posterior asymmetry in nontraumatized healthy controls varied with gender, with female participants showing a pattern of higher right posterior activation. The results support the hypothesis that symptomatic MVA survivors are characterized by a pattern of right hemisphere activation that is associated with anxious arousal and symptoms of PTSD during processing of trauma-specific information.     

Impact of Experimentally Induced Positive and Anxious Mood on Alcohol Expectancy Strength in Internally Motivated Drinkers

The effects of musically‐induced positive and anxious mood on explicit alcohol‐related cognitions (alcohol expectancy strength) in 47 undergraduate students who consume alcohol either to enhance positive mood states (for enhancement motives) or to cope with anxiety (for anxiety‐related coping motives) were investigated. Pre‐ and post‐mood induction, participants completed the emotional reward and emotional relief subscales of the Alcohol Craving Questionnaire – Now. The hypothesis that anxiety‐related coping motivated drinkers in the anxious mood condition (but not those in the positive mood condition) would exhibit increases in strength of explicit emotional relief alcohol expectancies after the mood induction was supported. An additional, unanticipated finding was that enhancement‐motivated drinkers in the anxious condition also showed significant increases in strength of explicit emotional relief (but not emotional reward) alcohol expectancies. The hypothesis that enhancement‐motivated (but not anxiety‐related coping motivated) participants would exhibit increases in explicit emotional reward expectancies following exposure to the positive mood induction procedure was not supported. Taken together with past research findings, the current results highlight the importance of distinguishing between subtypes of negative affect (i.e., anxious and depressed affect) in exploring the affective antecedents of explicit alcohol outcome expectancies.     

Effects of smoking and nicotine on EEG lateralization as a function of personality

The effects of nicotine/smoking on lateralization of the EEG were evaluated in 40 smokers while they responded to a low-stress, visual vigilance task. Smoking a high-nicotine cigarette was associated with a relatively larger increase in right hemisphere EEG arousal in extraverts and Type-A individuals, but with a relatively larger increase in left hemisphere EEG arousal in introverts and Type Bs. These findings suggest that nicotine/smoking may differentially influence the left and right hemispheres and that this interaction may be a function of personality.     

The Affective Consequences of Minority Stress Among Bisexual,Pansexual, and Queer (Bi+) Adults: A Daily Diary Study

Bisexual, pansexual, and queer (bi+) individuals are at increased risk for depression and anxiety. These disparities are hypothesized to be due to the unique, minority-specific stressors that they experience. Prior research supports that bi+ stressors are associated with depression and anxiety, but nearly all studies have been cross-sectional, limiting our understanding of how experiencing bi+ stress influences individuals’ levels of depression and anxiety as they occur in their day-to-day lives. To address this gap, we examined the daily associations between bi+ stressors (discrimination, internalized stigma, rejection sensitivity, and identity concealment) and depressed/anxious mood in a 28-day diary study. Participants were 208 bi+ individuals who completed daily measures of bi+ stressors and depressed/anxious mood. We tested unlagged (same-day) and lagged (next-day) associations, and we also tested whether internalized stigma, rejection sensitivity, and identity concealment functioned as mechanisms underlying the daily associations between discrimination and depressed/anxious mood. Participants reported higher depressed/anxious mood on days when they reported higher discrimination, internalized stigma, rejection sensitivity, and identity concealment. There were significant unlagged indirect effects of discrimination on depressed and anxious mood via internalized stigma and rejection sensitivity, and there was also a significant unlagged indirect effect of discrimination on anxiety via identity concealment. However, none of the lagged associations were significant. Results suggest that bi+ stress is related to same-day, but not next-day, depressed/anxious mood. The nonsignificant lagged associations could reflect that bi+ individuals are using adaptive coping skills in response to bi+ stress, or that other experiences throughout the day have stronger influences on next-day mood.     

Putative EEG measures of social anxiety: Comparing frontal alpha asymmetry and delta–beta cross-frequency correlation

The goal of the present study was to examine whether frontal alpha asymmetry and delta–beta cross-frequency correlation during resting state, anticipation, and recovery are electroencephalographic (EEG) measures of social anxiety. For the first time, we jointly examined frontal alpha asymmetry and delta–beta correlation during resting state and during a social performance task in high (HSA) versus low (LSA) socially anxious females. Participants performed a social performance task in which they first watched and evaluated a video of a peer, and then prepared their own speech. They believed that their speech would be videotaped and evaluated by a peer. We found that HSA participants showed significant negative delta–beta correlation as compared to LSA participants during both anticipation of and recovery from the stressful social situation. This negative delta–beta correlation might reflect increased activity in subcortical brain regions and decreased activity in cortical brain regions. As we hypothesized, no group differences in delta–beta correlation were found during the resting state. This could indicate that a certain level of stress is needed to find EEG measures of social anxiety. As for frontal alpha asymmetry, we did not find any group differences. The present frontal alpha asymmetry results are discussed in relation to the evident inconsistencies in the frontal alpha asymmetry literature. Together, our results suggest that delta–beta correlation is a putative EEG measure of social anxiety.     

Superior perception of phasic physiological arousal and the detrimental consequences of the conviction to be aroused on worrying and metacognitions in GAD

Although people suffering from generalized anxiety disorder (GAD) often report arousal symptoms, psychophysiological studies show no evidence of autonomic hyperarousal. Hypersensitivity toward and catastrophic interpretation of phasic arousal cues may explain this discrepancy. The authors tested (a) whether GAD sufferers perceive nonspecific skin conductance fluctuations (NSCFs), an indicator of phasic autonomic arousal, better than controls do and (b) whether the conviction to be aroused contributes to the maintenance of worrying and metacognitive beliefs about worrying. Thirty-three GAD sufferers and 34 healthy controls participated in 2 experiments. In Experiment 1, participants were asked to detect their own NSCFs during a signal detection task. GAD sufferers accurately detected more of their NSCFs than did controls, who tended to miss NSCFs. In Experiment 2, participants were instructed to relax following worry induction. While relaxing, they received nonveridical feedback indicating either arousal or relaxation. Arousal feedback conserved negative metacognitive beliefs regarding worrying and also maintained negative mood and worry exclusively in GAD participants. These findings suggest that superior perception of phasic arousal cues and their catastrophic misinterpretation increases worrying, negative metacognitive beliefs about worrying, and anxious mood in GAD.     

Frontal Brain Electrical Activity in Shyness and Sociability

A number of studies have shown that shyness and sociability may be two independent personality traits that are distinguishable across a variety of measures and cultures. Utilizing recent frontal activation–emotion models as a theoretical framework, this study examined the pattern of resting frontal electroencephalographic (EEG) activity in undergraduates who self-reported high and low shyness and sociability. Analyses revealed that shyness was associated with greater relative right frontal EEG activity, whereas sociability was associated with greater relative left frontal EEG activity. Also, different combinations of shyness and sociability were distinguishable on the basis of resting frontal EEG power. Although high-shy/high-social and high-shy/low-social subjects both exhibited greater relative right frontal EEG activity, they differed significantly on EEG power in the left, but not right, frontal lead. High-shy/high-social subjects exhibited significantly less EEG power (i.e., more activity) in the left frontal lead compared with the high-shy/low-social subjects. These findings suggest that in distinguishing individual differences in personality and personality subtypes, it is important to consider not only frontal EEG asymmetry measures, but also the pattern of absolute EEG power in each frontal hemisphere.     

The symptom perception hypothesis revised: depression and anxiety play different roles in concurrent and retrospective physical symptom reporting

According to the classic symptom perception hypothesis (Costa & McCrae, 1987; Watson & Pennebaker, 1989), the global predisposition to frequently experience a variety of negative emotions-that is, neuroticism (N) or trait negative affectivity (NA)-is associated with inflated physical symptom reporting. We tested a revision of this hypothesis, which posits distinctive roles for depression and anxiety in the physical symptom experience. Three studies tested predictions from the revised symptom perception hypothesis: (a) that depressive affect should be related to inflated retrospective physical symptom reports and (b) that anxious affect should be related to inflated concurrent, or momentary, physical symptom reports. Study 1 assessed the relations among N/NA, depressive affect, and recall of physical symptoms experienced in the previous 3 weeks. Depressive affect was uniquely and positively associated with recalling more symptoms. When entered with depressive affect in multiple regression analyses, neuroticism was not associated with level of symptoms recalled. In Study 2, participants were randomly assigned to anxious, depressed, angry, happy, or neutral mood inductions and then reported about concurrent symptom experience. Participants in the anxious mood condition reported significantly more concurrent physical symptoms than did those in the other 4 conditions. In Study 3, anxious, depressed, or neutral mood was induced, followed by assessment of both concurrent and retrospective physical symptoms. Those assigned to the anxious mood induction reported more concurrent symptoms, while those in the depressed mood condition reported having experienced more symptoms in the past. These findings are consistent with the idea that encoding and retrieval processes, which are differentially associated with anxious versus depressed affect, influence different aspects of physical symptom reporting. The results have implications for self-diagnosis, medical treatment-seeking, and care, and potential insights about other complex social and interpersonal behaviors are discussed.     

Is running away right? The behavioral activation-behavioral inhibition model of anterior asymmetry

The measurement of anterior electroencephalograph (EEG) asymmetries has become an important standard paradigm for the investigation of affective states and traits. Findings in this area are typically interpreted within the motivational direction model, which suggests a lateralization of approach and withdrawal motivational systems to the left and right anterior region, respectively. However, efforts to compare this widely adopted model with an alternative account-which relates the left anterior region to behavioral activation independent of the direction of behavior (approach or withdrawal) and the right anterior region to goal conflict-induced behavioral inhibition-are rare and inconclusive. Therefore, the authors measured the EEG in a sample of 93 young men during emotional imagery designed to provide a critical test between the 2 models. The results (e.g., a correlation between left anterior activation and withdrawal motivation) favor the alternative model on the basis of the concepts of behavioral activation and behavioral inhibition. In addition, the present study also supports an association of right parietal activation with physiological arousal and the conceptualization of parietal EEG asymmetry as a mediator of emotion-related physiological arousal.     

Impact of experimentally induced positive and anxious mood on alcohol expectancy strength in internally motivated drinkers

The effects of musically-induced positive and anxious mood on explicit alcohol-related cognitions (alcohol expectancy strength) in 47 undergraduate students who consume alcohol either to enhance positive mood states (for enhancement motives) or to cope with anxiety (for anxiety-related coping motives) were investigated. Pre- and post-mood induction, participants completed the emotional reward and emotional relief subscales of the Alcohol Craving Questionnaire - Now. The hypothesis that anxiety-related coping motivated drinkers in the anxious mood condition (but not those in the positive mood condition) would exhibit increases in strength of explicit emotional relief alcohol expectancies after the mood induction was supported. An additional, unanticipated finding was that enhancement-motivated drinkers in the anxious condition also showed significant increases in strength of explicit emotional relief (but not emotional reward) alcohol expectancies. The hypothesis that enhancement-motivated (but not anxiety-related coping motivated) participants would exhibit increases in explicit emotional reward expectancies following exposure to the positive mood induction procedure was not supported. Taken together with past research findings, the current results highlight the importance of distinguishing between subtypes of negative affect (i.e., anxious and depressed affect) in exploring the affective antecedents of explicit alcohol outcome expectancies.     

Depression, anxiety, and resting frontal EEG asymmetry: a meta-analytic review

Emotion-related disturbances, such as depression and anxiety, have been linked to relative right-sided resting frontal electroencephalograph (EEG) asymmetry among adults and infants of afflicted mothers. However, a somewhat inconsistent pattern of findings has emerged. A meta-analysis was undertaken to (a) evaluate the magnitude of effects across EEG studies of resting frontal asymmetry and depression, anxiety, and comorbid depression and anxiety and (b) determine whether certain moderator variables could help reconcile inconsistent findings. Moderate effects of similar magnitude were obtained for the depression and anxiety studies, whereas a smaller effect emerged for comorbid studies. Three moderating variables predicted effect sizes: (a) Shorter EEG recording periods were associated with larger effects among adults, (b) different operationalizations of depression yielded effects of marginally different magnitudes, and (c) younger infant samples showed larger effects than older ones. The current data support a link between resting frontal EEG asymmetry and depression and anxiety and provide a partial account of inconsistent findings across studies.