Frenk Peeters

Mindfulness Training Increases Momentary Positive Emotions and Reward Experience in Adults Vulnerable to Depression: A Randomized Controlled Trial

OBJECTIVE To examine whether mindfulness-based cognitive therapy (MBCT) increases momentary positive emotions and the ability to make use of natural rewards in daily life. METHOD Adults with a life-time history of depression and current residual depressive symptoms (mean age = 43.9 years, SD = 9.6; 75% female; all Caucasian) were randomized to MBCT (n = 64) or waitlist control (CONTROL; n = 66) in a parallel, open-label, randomized controlled trial. The Experience Sampling Method was used to measure momentary positive emotions as well as appraisal of pleasant activities in daily life during 6 days before and after the intervention. Residual depressive symptoms were measured using the 17-item Hamilton Depression Rating Scale (Hamilton, 1960). RESULTS MBCT compared to CONTROL was associated with significant increases in appraisals of positive emotion (b* = .39) and activity pleasantness (b* = .22) as well as enhanced ability to boost momentary positive emotions by engaging in pleasant activities (b* = .08; all ps < .005). Associations remained significant when corrected for reductions in depressive symptoms or for reductions in negative emotion, rumination, and worry. In the MBCT condition, increases in positive emotion variables were associated with reduction of residual depressive symptoms (all ps < .05). CONCLUSIONS MBCT is associated with increased experience of momentary positive emotions as well as greater appreciation of, and enhanced responsiveness to, pleasant daily-life activities. These changes were unlikely to be pure epiphenomena of decreased depression and, given the role of positive emotions in resilience against depression, may contribute to the protective effects of MBCT against depressive relapse.

Critical slowing down as early warning for the onset and termination of depression

Significance As complex systems such as the climate or ecosystems approach a tipping point, their dynamics tend to become dominated by a phenomenon known as critical slowing down. Using time series of autorecorded mood, we show that indicators of slowing down are also predictive of future transitions in depression. Specifically, in persons who are more likely to have a future transition, mood dynamics are slower and different aspects of mood are more correlated. This supports the view that the mood system may have tipping points where reinforcing feedbacks among a web of symptoms can propagate a person into a disorder. Our findings suggest the possibility of early warning systems for psychiatric disorders, using smartphone-based mood monitoring. About 17% of humanity goes through an episode of major depression at some point in their lifetime. Despite the enormous societal costs of this incapacitating disorder, it is largely unknown how the likelihood of falling into a depressive episode can be assessed. Here, we show for a large group of healthy individuals and patients that the probability of an upcoming shift between a depressed and a normal state is related to elevated temporal autocorrelation, variance, and correlation between emotions in fluctuations of autorecorded emotions. These are indicators of the general phenomenon of critical slowing down, which is expected to occur when a system approaches a tipping point. Our results support the hypothesis that mood may have alternative stable states separated by tipping points, and suggest an approach for assessing the likelihood of transitions into and out of depression.

A Network Approach to Psychopathology: New Insights into Clinical Longitudinal Data

In the network approach to psychopathology, disorders are conceptualized as networks of mutually interacting symptoms (e.g., depressed mood) and transdiagnostic factors (e.g., rumination). This suggests that it is necessary to study how symptoms dynamically interact over time in a network architecture. In the present paper, we show how such an architecture can be constructed on the basis of time-series data obtained through Experience Sampling Methodology (ESM). The proposed methodology determines the parameters for the interaction between nodes in the network by estimating a multilevel vector autoregression (VAR) model on the data. The methodology allows combining between-subject and within-subject information in a multilevel framework. The resulting network architecture can subsequently be analyzed through network analysis techniques. In the present study, we apply the method to a set of items that assess mood-related factors. We show that the analysis generates a plausible and replicable network architecture, the structure of which is related to variables such as neuroticism; that is, for subjects who score high on neuroticism, worrying plays a more central role in the network. Implications and extensions of the methodology are discussed.

Cortisol responses to daily events in major depressive disorder.

Objective Abnormal responses of the hypothalamic–pituitary–adrenal (HPA) axis to stress are thought to be involved in the pathophysiology of major depressive disorder (MDD). The aim of the present study was to determine whether cortisol responses to negative and positive daily events in depressed participants (N = 47) differed from such responses in healthy participants (N = 39). We also examined the influence of clinical characteristics and possible gender differences in cortisol responses to events. Finally, the role of mood changes in mediating cortisol responses was assessed. Methods Experience sampling methodology (self-reports of mood and events, with simultaneous saliva samples, 10 times each day for 6 consecutive days) and multilevel regression analysis were used to examine the relationship between events in daily life and salivary cortisol levels. Results In contrast to healthy participants, depressed participants showed no increase in cortisol following negative events. Responses were even more blunted in depressed participants with a family history of mood disorders. Although the effects of negative events on cortisol responses appeared to be mediated by changes in mood, negative affect tended to be less closely associated with cortisol levels in depressed participants. Depressed women showed larger cortisol responses to negative events than depressed men. Positive events had no effect on cortisol levels in either group. Conclusions These results suggest that responses of the HPA axis to negative daily events and mood changes are blunted in MDD. Future studies will need to address whether these abnormalities disappear after clinical recovery.

Correlates of autobiographical memory specificity: The role of depression, anxiety, and childhood trauma

The present study examined the role of childhood trauma, major depressive disorder (MDD), and anxiety disorder (AD) in overgeneral autobiographical memory. Ninety-three outpatients and 24 healthy controls completed a childhood trauma questionnaire and an autobiographical memory test (AMT). Results showed that MDD diagnosis rather than trauma history predicted AMT-performance. Memory specificity was not related to AD diagnosis, recovered MDD, or self-rated depression severity. The present findings cast doubts on theories that emphasize the role of childhood trauma in overgeneral autobiographical memory.

Rumination and worrying as possible mediators in the relation between neuroticism and symptoms of depression and anxiety in clinically depressed individuals

Rumination and worrying are considered possible mediating variables that may explain the relation between neuroticism and symptoms of depression and anxiety. The current study sought to examine the mediational effects of rumination and worry in the relationships between neuroticism and symptoms of depression and anxiety in a sample of clinically depressed individuals (N=198). All patients completed a battery of questionnaires including measures of neuroticism, rumination, worrying, depression, and anxiety. Results showed that in subsequent analyses, rumination and worrying both mediated the relation between neuroticism and depression and anxiety. When rumination and worrying were simultaneously entered in the mediation analysis, only rumination was found to mediate the relation between neuroticism and symptoms of anxiety and depression. Two components of rumination (i.e., brooding and reflection) were also analyzed in the mediational analysis. Both reflection and brooding were significant mediators with respect to depressive symptoms, whereas brooding was the only significant mediator in relation to anxiety symptoms. The results are discussed in the light of current theories, previous research, and recent treatment developments. Clinical implications and suggestions for future research are provided.

Evidence that moment‐to‐moment variation in positive emotions buffer genetic risk for depression: a momentary assessment twin study

Objective:  The negative affective response to daily life stressors, which previous work suggest is a fundamental depression endophenotype, may be moderated by positive emotions. It was investigated whether positive affect (PA) buffers negative affect (NA) reactivity in response to stress and whether PA moderates the genetic predisposition to negative affect reactivity.

Levels and variability of daily life cortisol secretion in major depression.

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is an important feature of major depressive disorder (MDD), but relatively little attention has been given to within-person variability of hormone secretion over time. Because most studies have been conducted in hospital settings, little information is available about naturally occurring patterns of cortisol secretion throughout the day in depressed outpatients. Multiple salivary cortisol samples were obtained over a 6-day period from 47 outpatients with MDD and 39 healthy controls in their everyday environment. We used multilevel regression analysis to estimate the effects of MDD and associated clinical characteristics on cortisol levels and intraindividual variability. Although more severe symptoms were associated with small elevations in cortisol levels, we found no clear evidence for hypercortisolism in the MDD group as a whole. However, cortisol output in MDD outpatients was less stable from sample to sample, as evidenced by a significantly lower autocorrelation than that observed in controls. Secretory patterns were particularly erratic in patients with more severe or recurrent episodes. Findings suggest that erratic cortisol secretion may be a more characteristic feature of HPA axis dysregulation in MDD than hypercortisolism, especially in outpatient populations.

A Time-Lagged Momentary Assessment Study on Daily Life Physical Activity and Affect

OBJECTIVE Novel study designs using within-subject methodology and frequent and prospective measurements are required to unravel direction of causality and dynamic processes of behavior over time. The current study examined the effects of physical activity on affective state. A primary and within-study replication sample was derived from twin pairs. METHODS Female twins (n = 504) participated in an experience sampling method study at baseline. Positive and negative affective changes were examined before and following daily life increases in physical activity. Neuroticism was measured at baseline and depressive symptoms were assessed at baseline and at each of four follow-up assessments. Diagnoses, derived by Structured Clinical Interview for Diagnostic and Statistical Manual for Mental Health-IV axis I disorders, (A. P. A., 1994) were obtained at baseline. RESULTS A significant increase in positive affect (PA) following the moment of increase in physical activity was replicated across both samples up to 180 min after physical activity. There was no effect of physical activity on negative affect (NA). Across the two samples, a history of fulfilling diagnostic criteria for depression at least once moderated the effect of physical activity on PA, in that the effect was lost more rapidly. CONCLUSIONS The study supports a causal effect of physical activity on PA. However, people with past experience of clinical depression may benefit less from the PA-inducing effect of physical activity. These findings have implications for the use of physical exercise in clinical practice.

Staging methods for treatment resistant depression. A systematic review

BACKGROUND Treatment resistant depressant (TRD) is classified in different staging models, but these are not used routinely. We aimed to identify staging models for TRD and compare them regarding predictive utility and reliability. METHODS Systematic review of Pubmed, Embase and PsycINFO (1985-January 2010) without language limits, plus articles identified from reference lists of previous reviews. We excluded articles focusing on TRD treatment. We qualitatively summarized characteristics of the identified staging models, describing strengths and limitations for each model. If available, we reported results of validation studies. RESULTS From 950 retrieved articles five staging models were found; the Antidepressant Treatment History Form, Thase and Rush Model, European Staging Model, Massachusetts General Hospital Staging model and the Maudsley Staging Model (MSM). Six studies investigated the predictive utility (of four models). We observed an evolution from single antidepressant adequacy ratings, towards a multidimensional and more continuous scored staging model which also introduced TRD characteristics (severity and duration). The operationalization criteria improved; the scoring of different treatment strategies (between/within class switching and augmentation/combination) changed according to the existing evidence. Over time, efforts to validate models improved. The predictive utility was assessed best for the MSM. LIMITATIONS Few staging models existed; their reliability was hardly assessed. CONCLUSIONS Despite validation of the MSM, further investigation of the reliability and predictive utility of TRD staging models and additional disease characteristics is required. Correct staging of TRD might improve generalizability of results from clinical studies and improve delivery of care to TRD patients. We propose methods to validate staging models in TRD.