Joelle LeMoult

Training Forgetting of Negative Material in Depression

In this study, the authors investigated whether training participants to use cognitive strategies can aid forgetting in depression. Participants diagnosed with major depressive disorder (MDD) and never-depressed participants learned to associate neutral cue words with a positive or negative target word and were then instructed not to think about the negative targets when shown their cues. The authors compared 3 different conditions: an unaided condition, a positive-substitute condition, and a negative-substitute condition. In the substitute conditions, participants were instructed to use new targets to keep from thinking about the original targets. After the training phase, participants were instructed to recall all targets when presented with the cues. MDD participants, in contrast with control participants, did not exhibit forgetting of negative words in the unaided condition. In both the negative and positive substitute conditions, however, MDD participants showed successful forgetting of negative words and a clear practice effect. In contrast, negative substitute words did not aid forgetting by the control participants. These findings suggest that training depressed individuals to use cognitive strategies can increase forgetting of negative words.

Attentional Disengagement Predicts Stress Recovery in Depression: An Eye-Tracking Study

Previous research has made significant progress elucidating the nature of cognitive biases in emotional disorders. However, less work has focused on the relation among cognitive biases and emotional responding in clinical samples. This study uses eye-tracking to examine difficulties disengaging attention from emotional material in depressed participants and to test its relation with mood reactivity and recovery during and after a stress induction. Participants diagnosed with Major Depressive Disorder (MDD) and never-disordered control participants (CTL) completed a novel eye-tracking paradigm in which participants had to disengage their attention from emotional material to attend to a neutral stimulus. Time to disengage attention was computed using a direct recording of eye movements. Participants then completed a stress induction and mood reactivity and recovery were assessed. MDD compared with CTL participants took significantly longer to disengage from depression-related stimuli (i.e., sad faces). Individual differences in disengagement predicted lower recovery from sad mood in response to the stress induction in the MDD group. These results suggest that difficulties in attentional disengagement may contribute to the sustained negative affect that characterizes depressive disorders.

Identification of Emotional Facial Expressions Following Recovery From Depression

This study investigated the identification of facial expressions of emotion in currently nondepressed participants who had a history of recurrent depressive episodes (recurrent major depression; RMD) and never-depressed control participants (CTL). Following a negative mood induction, participants were presented with faces whose expressions slowly changed from neutral to full intensity. Identification of facial expressions was measured by the intensity of the expression at which participants could accurately identify whether faces expressed happiness, sadness, or anger. There were no group differences in the identification of sad or angry expressions. Compared with CTL participants, however, RMD participants required significantly greater emotional intensity in the faces to correctly identify happy expressions. These results indicate that biases in the processing of emotional facial expressions are evident even after individuals have recovered from a depressive episode.

Telomere length and cortisol reactivity in children of depressed mothers

A growing body of research demonstrates that individuals diagnosed with major depressive disorder (MDD) are characterized by shortened telomere length, which has been posited to underlie the association between depression and increased instances of medical illness. The temporal nature of the relation between MDD and shortened telomere length, however, is not clear. Importantly, both MDD and telomere length have been associated independently with high levels of stress, implicating dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and anomalous levels of cortisol secretion in this relation. Despite these associations, no study has assessed telomere length or its relation with HPA-axis activity in individuals at risk for depression, before the onset of disorder. In the present study, we assessed cortisol levels in response to a laboratory stressor and telomere length in 97 healthy young daughters of mothers either with recurrent episodes of depression (i.e., daughters at familial risk for depression) or with no history of psychopathology. We found that daughters of depressed mothers had shorter telomeres than did daughters of never-depressed mothers and, further, that shorter telomeres were associated with greater cortisol reactivity to stress. This study is the first to demonstrate that children at familial risk of developing MDD are characterized by accelerated biological aging, operationalized as shortened telomere length, before they had experienced an onset of depression; this may predispose them to develop not only MDD but also other age-related medical illnesses. It is critical, therefore, that we attempt to identify and distinguish genetic and environmental mechanisms that contribute to telomere shortening.

Childhood adversity interacts separately with 5-HTTLPR and BDNF to predict lifetime depression diagnosis

The serotonin transporter polymorphism (5-HTTLPR) and the brain-derived neurotrophic factor (BDNF) val66met polymorphism have both been linked to depression symptoms and to depression diagnosis (MDD) in interaction with adversity; there have also been failures to find the effects. We reexamined both interactions for lifetime MDD in a college sample. Lifetime MDD was diagnosed by Structured Clinical Interview for DSM-IV in 133 undergraduates; genotypes for 5-HTTLPR and BDNF were assayed from blood, and self-reports were collected concerning childhood adversity (Risk). 5-HTTLPR interacted with Risk such that Risk predicted less likelihood of MDD among ll carriers and tended to predict greater likelihood of MDD among s carriers. BDNF interacted with Risk such that Risk predicted greater likelihood of MDD among met carriers and did not influence val/val carriers. These two interactions were additive: both were significant in a combined model.

Attention and Memory Biases in Social Anxiety Disorder: The Role of Comorbid Depression

Cognitive biases play an important role in the onset and maintenance of Social Anxiety Disorder (SAD). Few studies, however, have examined the role of comorbid Major Depressive Disorder (MDD) in the processing of emotional material. In addition, little is known about the relation among different cognitive biases. In the current study, 73 participants (54.79% female) completed an emotion face dot-probe task followed by a recognition memory test. Compared to participants with SAD, participants with comorbid SAD and MDD oriented away from supraliminally presented angry faces. Subsequently, SAD participants with and without comorbidity recognized fewer angry faces than non-disordered controls. Furthermore, attention biases for subliminally presented stimuli predicted recognition accuracy only for comorbid participants. These results suggest that the presence of comorbid MDD affects attentional orienting in SAD participants. In addition, it highlights the interconnectedness of attention and memory biases for comorbid participants.

Updating emotional content in working memory: A depression-specific deficit?

BACKGROUND AND OBJECTIVES Interference from irrelevant negative material might be a key mechanism underlying intrusive ruminative thoughts in depression. Considering commonalities between depression and social anxiety and the presence of similar intrusive thoughts in social anxiety, the current study was designed to assess whether interference from irrelevant material in working memory is specific to depression or is also present in social anxiety disorder. METHODS To examine the effects of irrelevant emotional material on working memory performance, participants memorized two lists of words on each trial and were subsequently instructed to ignore one of the lists. Participants were then asked to indicate whether a probe word belonged to the relevant list or not. RESULTS Compared to control and social anxiety groups, the depression groups (both pure and comorbid with social anxiety disorder) exhibited greater difficulties removing irrelevant emotional material from working memory (i.e., greater intrusion effects). Greater intrusion effects were also associated with increased rumination. LIMITATIONS Although we included three clinical groups (depression, social anxiety, and the comorbid groups), the results are based on a relatively small number of participants. CONCLUSIONS The results indicate that difficulties removing irrelevant material from working memory might be unique to depression, and the ability to inhibit irrelevant information is relatively preserved in social anxiety disorder.

Predicting first onset of depression in young girls: Interaction of diurnal cortisol and negative life events.

Interactions between biological vulnerability and environmental adversity are central to the pathophysiology of depression. Given evidence that the hypothalamic-pituitary-adrenal (HPA) axis influences biological responses to environmental events, in the current longitudinal study the authors examined HPA-axis functioning, negative life events, and their interaction as predictors of the first onset of depression. At baseline, girls ages 9 to 14 years provided saliva samples to assess levels of diurnal cortisol production, quantified by total cortisol production (area under the curve with respect to ground; AUCg) and the cortisol awakening response (CAR). The authors then followed these participants until they reached age 18 in order to assess their subsequent experience of negative life events and the onset of a depressive episode. They found that the influence of negative life events on the subsequent onset of depression depended on HPA-axis functioning at baseline. Specifically, negative life events predicted the onset of depression in girls with higher levels of AUCg, but not in girls with lower levels of AUCg. In contrast, CAR did not predict the onset of depression either alone or in interaction with negative life events. These findings suggest that elevated total cortisol production in daily life potentiates susceptibility to environmental adversity and signals the need for early intervention.

Depressive rumination alters cortisol decline in Major Depressive Disorder.

Depressive rumination - a central characteristic of Major Depressive Disorder (MDD) - is a maladaptive emotion regulation strategy that prolongs sad mood and depressive episodes. Considerable research demonstrates the emotional and behavioral consequences of depressive rumination, yet few studies investigate its effect on neuroendocrine functioning. The current study examined the effect of an emotion regulation manipulation on the trajectory of cortisol concentrations among individuals with MDD and healthy controls (CTL). Sadness was induced via forced failure. Participants then were randomly assigned to a depressive rumination or distraction emotion regulation induction. MDDs in the rumination condition exhibited less cortisol decline compared to MDDs in the distraction condition and compared to CTLs in either condition. Findings suggest that depressive rumination alters the trajectory of cortisol secretion in MDD and may prolong cortisol production. Results thereby provide important insights into the interaction of biological and psychological factors through which distress contributes to MDD.

The impact of the severity of early life stress on diurnal cortisol: The role of puberty

Researchers have documented dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis in children and adolescents who experienced early life stress (ELS). The precise nature of this dysregulation, however, has been difficult to discern. In fact, both elevated and blunted patterns of diurnal cortisol regulation have been reported in children and adolescents exposed to greater ELS, including both reduced and heightened cortisol levels and change in cortisol across the day. These divergent findings may be due to developmental changes in the relation between ELS and HPA-axis functioning. The present study was designed to examine the role of puberty in the impact of the severity of ELS on the regulation of diurnal cortisol. Boys and girls (N=145) ages 9-13 years recruited from lower-risk communities completed an interview about their ELS experiences and at-home collection of diurnal cortisol. ELS experiences were objectively coded for severity, and childrens level of pubertal development was measured using Tanner Staging. Multi-level piecewise mixed-effects models tested the effects of ELS severity and pubertal stage on cortisol levels at waking, the cortisol awakening response (CAR), and the daytime cortisol slope. While we found no significant interactive effects of pubertal stage and ELS severity on cortisol levels at waking or the daytime cortisol slope, findings indicated that pubertal stage interacted with ELS severity to predict the cortisol awakening response (CAR). Specifically, in earlier puberty, higher ELS was associated with a blunted CAR compared to lower ELS; in contrast, in later puberty, higher ELS was associated with a heightened CAR compared to lower ELS. Differences in the relation between ELS severity and the CAR were uniquely determined by puberty, and not by age. By considering and examining the role of puberty, the current study provides a developmental explanation for previous divergent findings of both blunted and heightened patterns of diurnal cortisol following ELS. These results indicate that careful attention should be given to childrens pubertal status before drawing conclusions concerning the nature of diurnal cortisol dysregulation.