Stress reduction correlates with structural changes in the amygdala

One of a kind: the neurobiology of individuality

What processes in the brain are responsible for individuality? Mounting imaging evidence suggests that brain circuits involved in our emotional responses are highly plastic and change with experience, affecting our temperament. Moreover, new research suggests that psychological interventions can further harness brain plasticity to promote positive behavioral changes that increase resilience and well-being.

Contributions of fMRI towards our understanding of the response to psychosocial stress in epilepsy and psychogenic nonepileptic seizures

There are multiple definitions of stress. For this review, as a reference point, we will use the concept of acute emotional/psychosocial stress ("stress"). The presence of acute stress has been reported to have a significant effect on seizure control, with several studies showing patients with seizure disorders being able to predict with reasonable accuracy seizure occurrence within the following hours or days. However, neuroimaging investigations of the pathophysiological mechanisms underlying stress reactivity (e.g., hypothalamic-pituitary-adrenal (HPA) axis activation) in humans, in general, and in patients with seizure disorders, in particular, are scarce. The reasons for this are multiple and likely include difficulty with designing appropriate probes that test various aspects of stress response, obtaining approval for studies that induce stress in patients who are prone to having stress-induced seizures, difficulties with assessing the physiological response to stress inside the scanner (e.g., heart rate, respiratory rate, oxygenation, cortisol levels, and galvanic skin responses), participant identification, and choice of epilepsy syndrome for investigation. With the recent explosion of neuroimaging literature focusing on correlating stress of various types and levels with cortical activations in healthy and diseased populations, it is incumbent upon us to examine the available neuroimaging data in patients with seizure disorders in order to identify the existing gaps and the needs/directions for future investigations. This approach is consistent with the goals of several of the 2014 Benchmarks for Epilepsy Research for the National Institute of Neurological Disorders and Stroke and the American Epilepsy Society.

Is meditation associated with altered brain structure? A systematic review and meta-analysis of morphometric neuroimaging in meditation practitioners

Numerous studies have begun to address how the brain's gray and white matter may be shaped by meditation. This research is yet to be integrated, however, and two fundamental questions remain: Is meditation associated with altered brain structure? If so, what is the magnitude of these differences? To address these questions, we reviewed and meta-analyzed 123 brain morphology differences from 21 neuroimaging studies examining ∼300 meditation practitioners. Anatomical likelihood estimation (ALE) meta-analysis found eight brain regions consistently altered in meditators, including areas key to meta-awareness (frontopolar cortex/BA 10), exteroceptive and interoceptive body awareness (sensory cortices and insula), memory consolidation and reconsolidation (hippocampus), self and emotion regulation (anterior and mid cingulate; orbitofrontal cortex), and intra- and interhemispheric communication (superior longitudinal fasciculus; corpus callosum). Effect size meta-analysis (calculating 132 effect sizes from 16 studies) suggests a global 'medium' effect size (Cohen's d¯=0.46; r¯=.19). Publication bias and methodological limitations are strong concerns, however. Further research using rigorous methods is required to definitively link meditation practice to altered brain morphology.

Person-Centered Spiritual Maturation

Person-centered spiritual maturation has conceptual and historical roots in my work with Carl Rogers, as a staff member of the Person-Centered Approach Project. It is a person-specific process of psychospiritual development that can be mentored in communities where belief systems and cultural identities are diverse. It enables individuals to deepen engagement with contemplative practices from spiritual traditions that hold personal salience, while building inclusive, respectful communities. This multidimensional model emerges from three decades mentoring person-centered spiritual maturation with university students in the service of their growth as professionals and socially responsible citizens. Growth includes (a) behavioral self-regulation through mindfulness; (b) cognitive understanding of humanity’s chain of pain that supports social justice; (c) social–emotional development that repairs broken attachment templates and promotes compassionate attunement to self and others; (d) contemplative practice that strengthens secure existential attachment and taps the human capacity for unconditional altruistic love; and (e) formation of a resilient worldview, confidence in life and self, that helps people confront life’s existential, interpersonal, and intergroup tensions with sufficient internal composure to derive maturational growth. This model provides a cohesive multidimensional explanation of person-centered spiritual maturation that highlights its prosocial value, integrates relevant neuroscience, and offers researchers a conceptual framework for future investigations.

Shifting brain asymmetry: the link between meditation and structural lateralization

Previous studies have revealed an increased fractional anisotropy and greater thickness in the anterior parts of the corpus callosum in meditation practitioners compared with control subjects. Altered callosal features may be associated with an altered inter-hemispheric integration and the degree of brain asymmetry may also be shifted in meditation practitioners. Therefore, we investigated differences in gray matter asymmetry as well as correlations between gray matter asymmetry and years of meditation practice in 50 long-term meditators and 50 controls. We detected a decreased rightward asymmetry in the precuneus in meditators compared with controls. In addition, we observed that a stronger leftward asymmetry near the posterior intraparietal sulcus was positively associated with the number of meditation practice years. In a further exploratory analysis, we observed that a stronger rightward asymmetry in the pregenual cingulate cortex was negatively associated with the number of practice years. The group difference within the precuneus, as well as the positive correlations with meditation years in the pregenual cingulate cortex, suggests an adaptation of the default mode network in meditators. The positive correlation between meditation practice years and asymmetry near the posterior intraparietal sulcus may suggest that meditation is accompanied by changes in attention processing.

Change in Brainstem Gray Matter Concentration Following a Mindfulness-Based Intervention is Correlated with Improvement in Psychological Well-Being

Individuals can improve their levels of psychological well-being (PWB) through utilization of psychological interventions, including the practice of mindfulness meditation, which is defined as the non-judgmental awareness of experiences in the present moment. We recently reported that an 8-week-mindfulness-based stress reduction (MBSR) course lead to increases in gray matter concentration in several brain areas, as detected with voxel-based morphometry of magnetization prepared rapid acquisition gradient echo MRI scans, including the pons/raphe/locus coeruleus area of the brainstem. Given the role of the pons and raphe in mood and arousal, we hypothesized that changes in this region might underlie changes in well-being. A subset of 14 healthy individuals from a previously published data set completed anatomical MRI and filled out the PWB scale before and after MBSR participation. PWB change was used as the predictive regressor for changes in gray matter density within those brain regions that had previously shown pre- to post-MBSR changes. Results showed that scores on five PWB subscales as well as the PWB total score increased significantly over the MBSR course. The change was positively correlated with gray matter concentration increases in two symmetrically bilateral clusters in the brainstem. Those clusters appeared to contain the area of the pontine tegmentum, locus coeruleus, nucleus raphe pontis, and the sensory trigeminal nucleus. No clusters were negatively correlated with the change in PWB. This preliminary study suggests a neural correlate of enhanced PWB. The identified brain areas include the sites of synthesis and release of the neurotransmitters, norepinephrine and serotonin, which are involved in the modulation of arousal and mood, and have been related to a variety of affective functions as well as associated clinical dysfunctions.

Neuroimaging for psychotherapy research: current trends

OBJECTIVE

This article reviews neuroimaging studies that inform psychotherapy research. An introduction to neuroimaging methods is provided as background for the increasingly sophisticated breadth of methods and findings appearing in psychotherapy research.

METHOD

We compiled and assessed a comprehensive list of neuroimaging studies of psychotherapy outcome, along with selected examples of other types of studies that also are relevant to psychotherapy research. We emphasized magnetic resonance imaging (MRI) since it is the dominant neuroimaging modality in psychological research.

RESULTS

We summarize findings from neuroimaging studies of psychotherapy outcome, including treatment for depression, obsessive compulsive disorder (OCD), and schizophrenia.

CONCLUSIONS

The increasing use of neuroimaging methods in the study of psychotherapy continues to refine our understanding of both outcome and process. We suggest possible directions for future neuroimaging studies in psychotherapy research.

Mindfulness training targets neurocognitive mechanisms of addiction at the attention-appraisal-emotion interface

Prominent neuroscience models suggest that addictive behavior occurs when environmental stressors and drug-relevant cues activate a cycle of cognitive, affective, and psychophysiological mechanisms, including dysregulated interactions between bottom-up and top-down neural processes, that compel the user to seek out and use drugs. Mindfulness-based interventions (MBIs) target pathogenic mechanisms of the risk chain linking stress and addiction. This review describes how MBIs may target neurocognitive mechanisms of addiction at the attention-appraisal-emotion interface. Empirical evidence is presented suggesting that MBIs ameliorate addiction by enhancing cognitive regulation of a number of key processes, including: clarifying cognitive appraisal and modulating negative emotions to reduce perseverative cognition and emotional arousal; enhancing metacognitive awareness to regulate drug-use action schema and decrease addiction attentional bias; promoting extinction learning to uncouple drug-use triggers from conditioned appetitive responses; reducing cue-reactivity and increasing cognitive control over craving; attenuating physiological stress reactivity through parasympathetic activation; and increasing savoring to restore natural reward processing. Treatment and research implications of our neurocognitive framework are presented. We conclude by offering a temporally sequenced description of neurocognitive processes targeted by MBIs through a hypothetical case study. Our neurocognitive framework has implications for the optimization of addiction treatment with MBIs.

Chronic pain resolution after a lucid dream: a case for neural plasticity?

Chronic pain is often managed using a multidisciplinary, biopsychosocial approach. Interventions targeting the biological, psychological, and social aspects of both the patient and the pain have been demonstrated to provide objective and subjective improvement in chronic pain symptoms. The mechanism by which pain attenuation occurs after these interventions remains to be elucidated. While there is a relatively large body of empirical literature suggesting that functional and structural changes in the peripheral and central nervous systems are key in the development and maintenance of chronic pain states, less is known about changes that take place in the nervous system as a whole after biopsychosocial interventions. Using as a model the unique case of Mr. S, a patient suffering with chronic pain for 22 years who experienced a complete resolution of pain after a lucid dream following 2 years of biopsychosocial treatments, we postulate that central nervous system (CNS) reorganization (i.e., neural plasticity) serves as a possible mechanism for the therapeutic benefit of multidisciplinary treatments, and may set a neural framework for healing, in this case via a lucid dream.

Bridging intimate partner violence and the human brain: a literature review

Past studies mainly focused on the physical and structural brain injuries in women survivors with a history of intimate partner violence (IPV), but little attention has been given to the biological impact and cognitive dysfunction resulting from such psychological stress. In this article, we aim to establish the connection between IPV and the brain by reviewing current literature examining (1) the biological mechanisms linking IPV, stress, and the brain; (2) the functional and anatomical considerations of the brain in abused women; and (3) the abused women's behavioral responses to IPV, including fear, pain, and emotion regulation, by utilizing functional neuroimaging. The major significance of this study is in highlighting the need to advance beyond self-reports and to obtain scientific evidence of the neurological impact and cognitive dysfunction in abused women with a history of IPV, an area in which current literature remains at a descriptive level.

Reducing stress and anxiety in caregivers of lung transplant patients: benefits of mindfulness meditation

BACKGROUND

Caregivers are a vital resource in the care of transplant candidates or recipients. However, few strategies have been tested that attempt to decrease the stress and anxiety they commonly encounter.

OBJECTIVE

To test the feasibility of using mindfulness-based stress reduction (MBSR) techniques to decrease stress and anxiety in caregivers of lung transplant candidates/recipients who required admission to an acute care facility.

METHODS

30 caregivers of lung transplant candidates/recipients were recruited during hospitalization of their significant other. Each completed the perceived stress scale (PSS) and state trait anxiety inventory (STAI) before and 4 weeks after receiving a DVD that demonstrated MBSR techniques. Participants were asked to practice MBSR techniques for 5-15 min a day for 4 weeks.

RESULTS

The participants had a mean±SD age of 55.6±13.6 years; 77% of participants were female and 93% Caucasian. The mean PSS and STAI (trait and anxiety) scores of caregivers were higher than population norms pre- and post-intervention. Scores for caregivers who stated they watched the entire DVD and practiced MBSR techniques as requested (n=15) decreased significantly from pre- to post-testing for perceived stress (p=0.001), state anxiety (p=0.003) and trait anxiety (p=0.006). Scores for those who watched some or none of the DVD (n=15) did not change significantly.

CONCLUSION

Caregivers can benefit from stress reduction techniques using MBSR.

Control over experience? Magnitude of the attentional blink depends on meditative state

The information processing capacity of the human mind is limited, as is evidenced by the so-called 'attentional-blink' deficit. This deficit is believed to result from competition between stimuli for limited attentional resources. We examined to what extent advanced meditators can manipulate their attentional state and control performance on an attentional blink task. We compared the magnitude of the attentional blink between states of focused attention meditation (in which one focuses tightly on an object) and states of open monitoring meditation (in which one is simply aware of whatever comes into experience) in a sample of experienced meditators. We found a smaller attentional blink during open monitoring compared to focused attention meditation due to reduced T1 capture. Of note, this effect was only found for very experienced meditators (on average 10,704 h of experience). These data may suggest that very advanced practitioners can exert some control over their conscious experience.

Positive parenting predicts the development of adolescent brain structure: a longitudinal study

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Positive parenting predicts development of adolescent amygdala and prefrontal cortex.

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Positive parenting has a unique influence on adolescent brain development.

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Positive and negative parenting are not opposite sides of a continuum.

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Parenting interventions may promote healthy adolescent brain development.

Little work has been conducted that examines the effects of positive environmental experiences on brain development to date. The aim of this study was to prospectively investigate the effects of positive (warm and supportive) maternal behavior on structural brain development during adolescence, using longitudinal structural MRI. Participants were 188 (92 female) adolescents, who were part of a longitudinal adolescent development study that involved mother–adolescent interactions and MRI scans at approximately 12 years old, and follow-up MRI scans approximately 4 years later. FreeSurfer software was used to estimate the volume of limbic-striatal regions (amygdala, hippocampus, caudate, putamen, pallidum, and nucleus accumbens) and the thickness of prefrontal regions (anterior cingulate and orbitofrontal cortices) across both time points. Higher frequency of positive maternal behavior during the interactions predicted attenuated volumetric growth in the right amygdala, and accelerated cortical thinning in the right anterior cingulate (males only) and left and right orbitofrontal cortices, between baseline and follow up. These results have implications for understanding the biological mediators of risk and protective factors for mental disorders that have onset during adolescence.

The beneficial effects of meditation: contribution of the anterior cingulate and locus coeruleus

During functional magnetic resonance imaging studies of meditation the cortical salience detecting and executive networks become active during "awareness of mind wandering," "shifting," and "sustained attention." The anterior cingulate (AC) is activated during "awareness of mind wandering." The AC modulates both the peripheral sympathetic nervous system (SNS) and the central locus coeruleus (LC) norepinephrine systems, which form the principal neuromodulatory system, regulating in multiple ways both neuronal and non-neuronal cells to maximize adaptation in changing environments. The LC is the primary source of central norepinephrine (C-NE) and nearly the exclusive source of cortical norepinephrine. Normally activated by novel or salient stimuli, the AC initially inhibits the SNS reflexively, lowering peripheral norepinephrine and activates the LC, increasing C-NE. Moderate levels of C-NE enhance working memory through alpha 2 adrenergic receptors, while higher levels of C-NE, acting on alpha 1 and beta receptors, enhance other executive network functions such as the stopping of ongoing behavior, attentional set-shifting, and sustained attention. The actions of the AC on both the central and peripheral noradrenergic systems are implicated in the beneficial effects of meditation. This paper will explore some of the known functions and interrelationships of the AC, SNS, and LC with respect to their possible relevance to meditation.

The brain on stress: vulnerability and plasticity of the prefrontal cortex over the life course

The prefrontal cortex (PFC) is involved in working memory and self-regulatory and goal-directed behaviors and displays remarkable structural and functional plasticity over the life course. Neural circuitry, molecular profiles, and neurochemistry can be changed by experiences, which influence behavior as well as neuroendocrine and autonomic function. Such effects have a particular impact during infancy and in adolescence. Behavioral stress affects both the structure and function of PFC, though such effects are not necessarily permanent, as young animals show remarkable neuronal resilience if the stress is discontinued. During aging, neurons within the PFC become less resilient to stress. There are also sex differences in the PFC response to stressors. While such stress and sex hormone-related alterations occur in regions mediating the highest levels of cognitive function and self-regulatory control, the fact that they are not necessarily permanent has implications for future behavior-based therapies that harness neural plasticity for recovery.

Stress and anxiety across the lifespan: structural plasticity and epigenetic regulation

The brain is the central organ of the body's response to and perception of stress. Both the juvenile and the adult brain show a significant capacity for lasting physiological, structural and behavioral plasticity as a consequence of stress exposure. The hypothesis that epigenetic mechanisms might lie behind the lasting effects of stress upon the brain has proven a fruitful one. In this review, we examine the growing literature showing that stress has a direct impact on epigenetic marks at all life history stages thus far examined and how, in turn, epigenetic mechanisms play a role in altering stress responsiveness, anxiety and brain plasticity across the lifespan and beyond to succeeding generations. In addition, we will examine our own recent findings that stress interacts with the epigenome to regulate the expression of transposable elements in a regionally specific fashion, a finding with significant implications for a portion of the genome which is tenfold larger than that occupied by the genes themselves.

How effective is the Forestry Commission Scotland's woodland improvement programme--'Woods In and Around Towns' (WIAT)--at improving psychological well-being in deprived urban communities? A quasi-experimental study

INTRODUCTION

There is a growing body of evidence that suggests that green spaces may positively influence psychological well-being. This project is designed to take advantage of a natural experiment where planned physical and social interventions to enhance access to natural environments in deprived communities provide an opportunity to prospectively assess impacts on perceived stress and mental well-being.

STUDY DESIGN AND METHODS

A controlled, prospective study comprising a repeat cross-sectional survey of residents living within 1.5 km of intervention and comparison sites. Three waves of data will be collected: prephysical environment intervention (2013); postphysical environment intervention (2014) and postwoodland promotion social intervention (2015). The primary outcome will be a measure of perceived stress (Perceived Stress Scale) preintervention and postintervention. Secondary, self-report outcomes include: mental well-being (Short Warwick-Edinburgh Mental Well-being Scale), changes in physical activity (IPAQ-short form), health (EuroQoL EQ-5D), perception and use of the woodlands, connectedness to nature (Inclusion of Nature in Self Scale), social cohesion and social capital. An environmental audit will complement the study by evaluating the physical changes in the environment over time and recording any other contextual changes over time. A process evaluation will assess the implementation of the programme. A health economics analysis will assess the cost consequences of each stage of the intervention in relation to the primary and secondary outcomes of the study.

ETHICS AND DISSEMINATION

Ethical approval has been given by the University of Edinburgh, Edinburgh College of Art Research, Ethics and Knowledge Exchange Committee (ref. 19/06/2012). Findings will be disseminated through peer-reviewed publications, national and international conferences and, at the final stage of the project, through a workshop for those interested in implementing environmental interventions.

Brain structural basis of cognitive reappraisal and expressive suppression

Cognitive reappraisal and expressive suppression, two major emotion regulation strategies, are differentially related to emotional well-being. The aim of this study was to test the association of individual differences in these two emotion regulation strategies with gray matter volume of brain regions that have been shown to be involved in the regulation of emotions. Based on high-resolution magnetic resonance images of 96 young adults voxel-based morphometry was used to analyze the gray matter volumes of the a priori regions of interest, including amygdala, insula, dorsal anterior cingulate and paracingulate cortex, medial and lateral prefrontal cortex (PFC) and their association with cognitive reappraisal and expressive suppression usage as well as neuroticism. A positive association of cognitive reappraisal with right and tendentially left amygdala volume and of neuroticism with left amygdala volume (marginally significant) was found. Expressive suppression was related to dorsal anterior cingulate/paracingulate cortex and medial PFC gray matter volume. The results of this study emphasize the important role of the amygdala in individual differences in cognitive reappraisal usage as well as neuroticism. Additionally, the association of expressive suppression usage with larger volumes of the medial PFC and dorsal anterior/paracingulate cortex underpins the role of these regions in regulating emotion-expressive behavior.

Prenatal cocaine exposure alters functional activation in the ventral prefrontal cortex and its structural connectivity with the amygdala

Prenatal cocaine exposure (PCE) is associated with arousal dysregulation, and alterations of amygdala activity in response to emotional arousal have previously been reported. However, voluntary regulation of emotional affect, enabling appropriate neural response to different streams of stimuli, must also engage prefrontal regions, yet the impact of PCE on these prefrontal mechanisms has not been investigated. Recent neuroimaging studies have shown the involvement of ventral prefrontal cortex (vPFC) in the modulation of amygdala reactivity and the mediation of effective emotional regulation. Based on these findings, using functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI), the present study compared functional activations of the vPFC as well as its structural connectivity with the amygdala between groups of PCE and control adolescents. In a working memory task with emotional distracters, the PCE adolescents exhibited less capability of increasing their vPFC activation in response to increased memory load, which corresponded with their less suppressed amygdala activation. Reduced structural connectivity between the vPFC and the amygdala was also observed from DTI measurement in the PCE group. In addition, correlations between amygdala activation and (i) vPFC activation, as well as (ii) amygdala-vPFC structural connectivity, were observed in the control but not in the PCE group. These data complement previous findings of the impact of PCE on the activity of the amygdala and extend our understanding of the neurobiological mechanisms underlying the effect of PCE on arousal dysregulation reported in human and animal studies.

Meditation effects within the hippocampal complex revealed by voxel-based morphometry and cytoarchitectonic probabilistic mapping

Scientific studies addressing anatomical variations in meditators' brains have emerged rapidly over the last few years, where significant links are most frequently reported with respect to gray matter (GM). To advance prior work, this study examined GM characteristics in a large sample of 100 subjects (50 meditators, 50 controls), where meditators have been practicing close to 20 years, on average. A standard, whole-brain voxel-based morphometry approach was applied and revealed significant meditation effects in the vicinity of the hippocampus, showing more GM in meditators than in controls as well as positive correlations with the number of years practiced. However, the hippocampal complex is regionally segregated by architecture, connectivity, and functional relevance. Thus, to establish differential effects within the hippocampal formation (cornu ammonis, fascia dentata, entorhinal cortex, subiculum) as well as the hippocampal-amygdaloid transition area, we utilized refined cytoarchitectonic probabilistic maps of (peri-) hippocampal subsections. Significant meditation effects were observed within the subiculum specifically. Since the subiculum is known to play a key role in stress regulation and meditation is an established form of stress reduction, these GM findings may reflect neuronal preservation in long-term meditators—perhaps due to an attenuated release of stress hormones and decreased neurotoxicity.

Neuropsychiatric symptoms and the use of mind-body therapies

OBJECTIVE

Neuropsychiatric symptoms affect 37% of US adults and present in many important diagnoses including posttraumatic stress disorder, traumatic brain injury, and chronic pain. However, these symptoms are difficult to treat with standard treatments, and patients may seek alternative options. In this study, we examined the use of mind-body therapies by adults with neuropsychiatric symptoms.

METHOD

We compared mind-body therapy use (biofeedback, energy healing, meditation, guided imagery, yoga, deep-breathing exercises, hypnosis, progressive relaxation therapy, qigong, and tai chi) between adults with and without neuropsychiatric symptoms (anxiety, depression, insomnia, headaches, memory deficits, attention deficits, and excessive daytime sleepiness) in the 2007 National Health Interview Survey (N = 23,393). Use of ≥ 1 of these therapies in the prior 12 months was the primary outcome of interest. We also examined prevalence and reasons for mind-body therapy use in adults with neuropsychiatric symptoms. We performed logistic regression to examine the association between neuropsychiatric symptoms and mind-body therapy use to adjust for sociodemographic and clinical factors.

RESULTS

Adults with ≥ 1 neuropsychiatric symptom used mind-body therapies more than adults without symptoms (25.3% vs 15.0%, P < .001). Prevalence increased with increasing number of symptoms (21.5% for 1 symptom, 32.4% for ≥ 3 symptoms, P < .001); differences persisted after adjustment for potential confounders (odds ratios, 1.39 [95% CI, 1.26-1.53] and 2.48 [95% CI, 2.18-2.82]). Reasons for mind-body therapy use among adults with ≥ 1 symptom included the ineffectiveness or expense of conventional medicine (30.2%). Most adults (nearly 70%) with ≥ 1 symptom did not discuss their mind-body therapy use with a conventional provider.

CONCLUSIONS

Adults with ≥ 1 neuropsychiatric symptom use mind-body therapies frequently; more symptoms are associated with increased use. Future research is needed to understand the efficacy of these therapies.

Retraining the addicted brain: a review of hypothesized neurobiological mechanisms of mindfulness-based relapse prevention

Addiction has generally been characterized as a chronic relapsing condition (Leshner, 1999). Several laboratory, preclinical, and clinical studies have provided evidence that craving and negative affect are strong predictors of the relapse process. These states, as well as the desire to avoid them, have been described as primary motives for substance use. A recently developed behavioral treatment, mindfulness-based relapse prevention (MBRP), was designed to target experiences of craving and negative affect and their roles in the relapse process. MBRP offers skills in cognitive-behavioral relapse prevention integrated with mindfulness meditation. The mindfulness practices in MBRP are intended to increase discriminative awareness, with a specific focus on acceptance of uncomfortable states or challenging situations without reacting "automatically." A recent efficacy trial found that those randomized to MBRP, as compared with those in a control group, demonstrated significantly lower rates of substance use and greater decreases in craving following treatment. Furthermore, individuals in MBRP did not report increased craving or substance use in response to negative affect. It is important to note, areas of the brain that have been associated with craving, negative affect, and relapse have also been shown to be affected by mindfulness training. Drawing from the neuroimaging literature, we review several plausible mechanisms by which MBRP might be changing neural responses to the experiences of craving and negative affect, which subsequently may reduce risk for relapse. We hypothesize that MBRP may affect numerous brain systems and may reverse, repair, or compensate for the neuroadaptive changes associated with addiction and addictive-behavior relapse.

Dispositional mindfulness co-varies with smaller amygdala and caudate volumes in community adults

Mindfulness, a psychological process reflecting attention and awareness to what is happening in the present moment, has been associated with increased well-being and decreased depression and anxiety in both healthy and patient populations. However, little research has explored underlying neural pathways. Recent work suggests that mindfulness (and mindfulness training interventions) may foster neuroplastic changes in cortico-limbic circuits responsible for stress and emotion regulation. Building on this work, we hypothesized that higher levels of dispositional mindfulness would be associated with decreased grey matter volume in the amgydala. In the present study, a self-report measure of dispositional mindfulness and structural MRI images were obtained from 155 healthy community adults. Volumetric analyses showed that higher dispositional mindfulness is associated with decreased grey matter volume in the right amygdala, and exploratory analyses revealed that higher dispositional mindfulness is also associated with decreased grey matter volume in the left caudate. Moreover, secondary analyses indicate that these amygdala and caudate volume associations persist after controlling for relevant demographic and individual difference factors (i.e., age, total grey matter volume, neuroticism, depression). Such volumetric differences may help explain why mindful individuals have reduced stress reactivity, and suggest new candidate structural neurobiological pathways linking mindfulness with mental and physical health outcomes.

The tricks of the trait: neural implementation of personality varies with genotype-dependent serotonin levels

Gray's Reinforcement Sensitivity Theory (RST) has developed into one of the most prominent personality theories of the last decades. The RST postulates a Behavioral Inhibition System (BIS) modulating the reaction to stimuli indicating aversive events. A number of psychiatric disorders including depression, anxiety disorders, and psychosomatic illnesses have been associated with extreme BIS responsiveness. In recent years, neuroimaging studies have implicated the amygdala-septo-hippocampal circuit as an important neural substrate of the BIS. However, the neurogenetic basis of the regulation of this behaviorally and clinically essential system remains unclear. Investigating the effects of two functional genetic polymorphisms (tryptophan hydroxylase-2, G-703T, and serotonin transporter, serotonin transporter gene-linked polymorphic region) in 89 human participants, we find significantly different patterns of associations between BIS scores and amygdala-hippocampus connectivity during loss anticipation for genotype groups regarding both polymorphisms. Specifically, the correlation between amygdala-hippocampus connectivity and Gray's trait anxiety scores is positive in individuals homozygous for the TPH2 G-allele, while carriers of at least one T-allele show a negative association. Likewise, individuals homozygous for the 5-HTTLPR L(A) variant display a positive association while carriers of the S/L(G) allele show a trend towards a negative association. Thus, we show converging evidence of different neural implementation of the BIS depending on genotype-dependent levels of serotonin. We provide evidence suggesting that genotype-dependent serotonin levels and thus putative changes in the efficiency of serotonergic neurotransmission might not only alter brain activation levels directly, but also more fundamentally impact the neural implementation of personality traits. We outline the direct clinical implications arising from this finding and discuss the complex interplay of neural responses, genes and personality traits in this context.

Mindfulness and emotion regulation--an fMRI study

Mindfulness--an attentive non-judgmental focus on present experiences--is increasingly incorporated in psychotherapeutic treatments as a skill fostering emotion regulation. Neurobiological mechanisms of actively induced emotion regulation are associated with prefrontally mediated down-regulation of, for instance, the amygdala. We were interested in neurobiological correlates of a short mindfulness instruction during emotional arousal. Using functional magnetic resonance imaging, we investigated effects of a short mindfulness intervention during the cued expectation and perception of negative and potentially negative pictures (50% probability) in 24 healthy individuals compared to 22 controls. The mindfulness intervention was associated with increased activations in prefrontal regions during the expectation of negative and potentially negative pictures compared to controls. During the perception of negative stimuli, reduced activation was identified in regions involved in emotion processing (amygdala, parahippocampal gyrus). Prefrontal and right insular activations when expecting negative pictures correlated negatively with trait mindfulness, suggesting that more mindful individuals required less regulatory resources to attenuate emotional arousal. Our findings suggest emotion regulatory effects of a short mindfulness intervention on a neurobiological level.

Annual Research Review: The neurobiology and physiology of resilience and adaptation across the life course

BACKGROUND

Adaptation is key to survival. An organism must adapt to environmental challenges in order to be able to thrive in the environment in which they find themselves. Resilience can be thought of as a measure of the ability of an organism to adapt, and to withstand challenges to its stability. In higher animals, the brain is a key player in this process of adaptation and resilience, and through a process known as "allostasis" can obtain "stability through change"; protecting homeostasis in the face of stressors in the environment. Mediators of allostasis, such as glucocorticoids, can cause changes in the structure and function of neural circuits, clearly impacting behavior. How developmental stage interacts with stress and leads to long-lasting changes is a key question addressed in this review.

SCOPE AND METHODS

We discuss the concept of allostasis, its role in resilience, the neural and physiological systems mediating these responses, the modulatory role of development, and the consequences for adult functioning. We present this in the context of mediators the brain and body engage to protect against threats to homeostasis. The review has been informed by comprehensive searches on PubMed and Scopus through November 2012.

FINDINGS

Stressors in the environment can have long lasting effects on development, depending upon the stage of life at which they are experienced. As such, adverse childhood experiences can alter resilience of individuals, making it more difficult for them to respond normally to adverse situations in adulthood, but the brain maintains the capacity to re-enter a more plastic state where such effects can be mitigated.

CONCLUSIONS

The brain regulates responses that allow for adaptation to challenges in the environment. The capacity of the brain and body to withstand challenges to stability can be considered as "resilience". While adverse childhood experiences can have long-term negative consequences, under the right circumstances, the brain can re-enter plastic states, and negative outcomes may be mitigated, even later in life.

Neural mechanisms of symptom improvements in generalized anxiety disorder following mindfulness training

Mindfulness training aims to impact emotion regulation. Generalized anxiety disorder (GAD) symptoms can be successfully addressed through mindfulness-based interventions. This preliminary study is the first to investigate neural mechanisms of symptom improvements in GAD following mindfulness training. Furthermore, we compared brain activation between GAD patients and healthy participants at baseline. 26 patients with a current DSM-IV GAD diagnosis were randomized to an 8-week Mindfulness Based Stress Reduction (MBSR, N = 15) or a stress management education (SME, N = 11) active control program. 26 healthy participants were included for baseline comparisons. BOLD response was assessed with fMRI during affect labeling of angry and neutral facial expressions. At baseline, GAD patients showed higher amygdala activation than healthy participants in response to neutral, but not angry faces, suggesting that ambiguous stimuli reveal stronger reactivity in GAD patients. In patients, amygdala activation in response to neutral faces decreased following both interventions. BOLD response in ventrolateral prefrontal regions (VLPFC) showed greater increase in MBSR than SME participants. Functional connectivity between amygdala and PFC regions increased significantly pre- to post-intervention within the MBSR, but not SME group. Both, change in VLPFC activation and amygdala–prefrontal connectivity were correlated with change in Beck Anxiety Inventory (BAI) scores, suggesting clinical relevance of these changes. Amygdala–prefrontal connectivity turned from negative coupling (typically seen in down-regulation of emotions), to positive coupling; potentially suggesting a unique mechanism of mindfulness. Findings suggest that in GAD, mindfulness training leads to changes in fronto-limbic areas crucial for the regulation of emotion; these changes correspond with reported symptom improvements.

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GAD patients show higher amygdala activation to neutral faces than healthy subjects.

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In GAD patients, amygdala activation decreased after stress reduction interventions.

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Ventrolateral PFC activation during affect labeling increases following mindfulness.

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Amygdala–PFC functional connectivity increases following mindfulness.

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These changes following mindfulness correlate with improvements in anxiety symptoms.

Single treatments that have lasting effects: some thoughts on the antidepressant effects of ketamine and botulinum toxin and the anxiolytic effect of psilocybin

Recent clinical trials suggest that 3 single biological treatments have effects that persist. Based on research showing that the muscles involved in facial expressions can feed back to influence mood, a single trial diminishing glabella frown lines with botulinum toxin demonstrated a significant antidepressant effect for 16 weeks. Based primarily on research with animal models of depression suggesting that glutamate may be involved in depression, the N-methyl-D-aspartate antagonist ketamine has been tested in several trials. A single dose decreased depression for up to a week. The reported effects of the use of mushrooms containing psilocybin by a number of cultures around the world has stimulated several trials showing beneficial effects of a single dose of psilocybin for over a year in healthy people, and for up to 3 months in patients with anxiety disorders who have advanced cancer. This article discusses these studies, their rationale, their possible mechanisms of action, the future clinical research required to establish these therapies and the basic research required to optimize single treatments that have lasting effects.

Meditation-related activations are modulated by the practices needed to obtain it and by the expertise: an ALE meta-analysis study

The brain network governing meditation has been studied using a variety of meditation practices and techniques practices eliciting different cognitive processes (e.g., silence, attention to own body, sense of joy, mantras, etc.). It is very possible that different practices of meditation are subserved by largely, if not entirely, disparate brain networks. This assumption was tested by conducting an activation likelihood estimation (ALE) meta-analysis of meditation neuroimaging studies, which assessed 150 activation foci from 24 experiments. Different ALE meta-analyses were carried out. One involved the subsets of studies involving meditation induced through exercising focused attention (FA). The network included clusters bilaterally in the medial gyrus, the left superior parietal lobe, the left insula and the right supramarginal gyrus (SMG). A second analysis addressed the studies involving meditation states induced by chanting or by repetition of words or phrases, known as “mantra.” This type of practice elicited a cluster of activity in the right SMG, the SMA bilaterally and the left postcentral gyrus. Furthermore, the last analyses addressed the effect of meditation experience (i.e., short- vs. long-term meditators). We found that frontal activation was present for short-term, as compared with long-term experience meditators, confirming that experts are better enabled to sustain attentional focus, rather recruiting the right SMG and concentrating on aspects involving disembodiment.

Mindfulness therapy for somatization disorder and functional somatic syndromes: randomized trial with one-year follow-up

OBJECTIVE

To conduct a feasibility and efficacy trial of mindfulness therapy in somatization disorder and functional somatic syndromes such as fibromyalgia, irritable bowel syndrome, and chronic fatigue syndrome, defined as bodily distress syndrome (BDS).

METHODS

We randomized 119 patients to either mindfulness therapy (mindfulness-based stress reduction and some cognitive behavioral therapy elements for BDS) or to enhanced treatment as usual (2-hour specialist medical care and brief cognitive behavioral therapy for BDS). The primary outcome measure was change in physical health (SF-36 Physical Component Summary) from baseline to 15-month follow-up.

RESULTS

The study is negative as we could not demonstrate a different development over time for the two groups (F(3,2674)=1.51, P=.21). However, in the mindfulness therapy group, improvement was obtained toward the end of treatment and it remained present at the 15-month follow-up, whereas the enhanced treatment as usual group achieved no significant change until 15-month follow-up. The change scores averaged half a standard deviation which amounts to a clinically significant change, 29% changed more than 1 standard deviation. Significant between-group differences were observed at treatment cessation.

CONCLUSION

Mindfulness therapy is a feasible and acceptable treatment. The study showed that mindfulness therapy was comparable to enhanced treatment as usual in improving quality of life and symptoms. Nevertheless, considering the more rapid improvement following mindfulness, mindfulness therapy may be a potentially useful intervention in BDS patients. Clinically important changes that seem to be comparable to a CBT treatment approach were obtained. Further research is needed to replicate or even expand these findings.

Cyr N, Khalsa D, Lin J, Blackburn E, Epel E, Irwin MR. A pilot study of yogic meditation for family dementia caregivers with depressive symptoms: effects on mental health, cognition, and telomerase activity

BACKGROUND

This study examined the effects of brief daily yogic meditation on mental health, cognitive functioning, and immune cell telomerase activity in family dementia caregivers with mild depressive symptoms.

METHODS

Thirty-nine family dementia caregivers (mean age 60.3 years old (SD = 10.2)) were randomized to practicing Kirtan Kriya or listening to relaxation music for 12 min per day for 8 weeks. The severity of depressive symptoms, mental and cognitive functioning were assessed at baseline and follow-up. Telomerase activity in peripheral blood mononuclear cells (PMBC) was examined in peripheral PBMC pre-intervention and post-intervention.

RESULTS

The meditation group showed significantly lower levels of depressive symptoms and greater improvement in mental health and cognitive functioning compared with the relaxation group. In the meditation group, 65.2% showed 50% improvement on the Hamilton Depression Rating scale and 52% of the participants showed 50% improvement on the Mental Health Composite Summary score of the Short Form-36 scale compared with 31.2% and 19%, respectively, in the relaxation group (p < 0.05). The meditation group showed 43% improvement in telomerase activity compared with 3.7% in the relaxation group (p = 0.05).

CONCLUSION

This pilot study found that brief daily meditation practices by family dementia caregivers can lead to improved mental and cognitive functioning and lower levels of depressive symptoms. This improvement is accompanied by an increase in telomerase activity suggesting improvement in stress-induced cellular aging. These results need to be confirmed in a larger sample.

Pre-existing brain function predicts subsequent practice of mindfulness and compassion meditation

While a variety of meditation techniques are increasingly employed as health interventions, the fact that meditation requires a significant commitment of time and effort may limit its potential widespread utility. In the current study, we ask whether baseline subjective reports or brain activity in response to a "Pain for Self and Others" paradigm predicts subsequent engagement in mindfulness and compassion meditation. The study also investigated whether compassion training would impact neural responses when compared to an active health education control group. Prior to training, activation of the left and right anterior insula, an area thought to be important for empathy, in response to the Other pain task was positively related to engagement with compassion meditation as measured by practice time (n=13). On the other hand, activity in the left amygdala during the Self pain task was negatively correlated with mindfulness practice time. Following the study intervention, there was no difference between the compassion group (n=13), and the control group (n=8), in brain responses to either the Self or Other task. These results are the first to indicate that baseline neural responses may predict engagement with meditation training and suggest that pre-existing neurobiological profiles differentially predispose individuals to engage with disparate meditation techniques.

The Multidimensional Assessment of Interoceptive Awareness (MAIA)

This paper describes the development of a multidimensional self-report measure of interoceptive body awareness. The systematic mixed-methods process involved reviewing the current literature, specifying a multidimensional conceptual framework, evaluating prior instruments, developing items, and analyzing focus group responses to scale items by instructors and patients of body awareness-enhancing therapies. Following refinement by cognitive testing, items were field-tested in students and instructors of mind-body approaches. Final item selection was achieved by submitting the field test data to an iterative process using multiple validation methods, including exploratory cluster and confirmatory factor analyses, comparison between known groups, and correlations with established measures of related constructs. The resulting 32-item multidimensional instrument assesses eight concepts. The psychometric properties of these final scales suggest that the Multidimensional Assessment of Interoceptive Awareness (MAIA) may serve as a starting point for research and further collaborative refinement.

Effects of mindful-attention and compassion meditation training on amygdala response to emotional stimuli in an ordinary, non-meditative state

The amygdala has been repeatedly implicated in emotional processing of both positive and negative-valence stimuli. Previous studies suggest that the amygdala response to emotional stimuli is lower when the subject is in a meditative state of mindful-attention, both in beginner meditators after an 8-week meditation intervention and in expert meditators. However, the longitudinal effects of meditation training on amygdala responses have not been reported when participants are in an ordinary, non-meditative state. In this study, we investigated how 8 weeks of training in meditation affects amygdala responses to emotional stimuli in subjects when in a non-meditative state. Healthy adults with no prior meditation experience took part in 8 weeks of either Mindful Attention Training (MAT), Cognitively-Based Compassion Training (CBCT; a program based on Tibetan Buddhist compassion meditation practices), or an active control intervention. Before and after the intervention, participants underwent an fMRI experiment during which they were presented images with positive, negative, and neutral emotional valences from the IAPS database while remaining in an ordinary, non-meditative state. Using a region-of-interest analysis, we found a longitudinal decrease in right amygdala activation in the Mindful Attention group in response to positive images, and in response to images of all valences overall. In the CBCT group, we found a trend increase in right amygdala response to negative images, which was significantly correlated with a decrease in depression score. No effects or trends were observed in the control group. This finding suggests that the effects of meditation training on emotional processing might transfer to non-meditative states. This is consistent with the hypothesis that meditation training may induce learning that is not stimulus- or task-specific, but process-specific, and thereby may result in enduring changes in mental function.

Self-awareness, self-regulation, and self-transcendence (S-ART): a framework for understanding the neurobiological mechanisms of mindfulness

Mindfulness-as a state, trait, process, type of meditation, and intervention has proven to be beneficial across a diverse group of psychological disorders as well as for general stress reduction. Yet, there remains a lack of clarity in the operationalization of this construct, and underlying mechanisms. Here, we provide an integrative theoretical framework and systems-based neurobiological model that explains the mechanisms by which mindfulness reduces biases related to self-processing and creates a sustainable healthy mind. Mindfulness is described through systematic mental training that develops meta-awareness (self-awareness), an ability to effectively modulate one's behavior (self-regulation), and a positive relationship between self and other that transcends self-focused needs and increases prosocial characteristics (self-transcendence). This framework of self-awareness, -regulation, and -transcendence (S-ART) illustrates a method for becoming aware of the conditions that cause (and remove) distortions or biases. The development of S-ART through meditation is proposed to modulate self-specifying and narrative self-networks through an integrative fronto-parietal control network. Relevant perceptual, cognitive, emotional, and behavioral neuropsychological processes are highlighted as supporting mechanisms for S-ART, including intention and motivation, attention regulation, emotion regulation, extinction and reconsolidation, prosociality, non-attachment, and decentering. The S-ART framework and neurobiological model is based on our growing understanding of the mechanisms for neurocognition, empirical literature, and through dismantling the specific meditation practices thought to cultivate mindfulness. The proposed framework will inform future research in the contemplative sciences and target specific areas for development in the treatment of psychological disorders.

Self-awareness, self-regulation, and self-transcendence (S-ART): a framework for understanding the neurobiological mechanisms of mindfulness

Mindfulness—as a state, trait, process, type of meditation, and intervention has proven to be beneficial across a diverse group of psychological disorders as well as for general stress reduction. Yet, there remains a lack of clarity in the operationalization of this construct, and underlying mechanisms. Here, we provide an integrative theoretical framework and systems-based neurobiological model that explains the mechanisms by which mindfulness reduces biases related to self-processing and creates a sustainable healthy mind. Mindfulness is described through systematic mental training that develops meta-awareness (self-awareness), an ability to effectively modulate one's behavior (self-regulation), and a positive relationship between self and other that transcends self-focused needs and increases prosocial characteristics (self-transcendence). This framework of self-awareness, -regulation, and -transcendence (S-ART) illustrates a method for becoming aware of the conditions that cause (and remove) distortions or biases. The development of S-ART through meditation is proposed to modulate self-specifying and narrative self-networks through an integrative fronto-parietal control network. Relevant perceptual, cognitive, emotional, and behavioral neuropsychological processes are highlighted as supporting mechanisms for S-ART, including intention and motivation, attention regulation, emotion regulation, extinction and reconsolidation, prosociality, non-attachment, and decentering. The S-ART framework and neurobiological model is based on our growing understanding of the mechanisms for neurocognition, empirical literature, and through dismantling the specific meditation practices thought to cultivate mindfulness. The proposed framework will inform future research in the contemplative sciences and target specific areas for development in the treatment of psychological disorders.

Mindfulness: top-down or bottom-up emotion regulation strategy?

The beneficial clinical effects of mindfulness practices are receiving increasing support from empirical studies. However, the functional neural mechanisms underlying these benefits have not been thoroughly investigated. Some authors suggest that mindfulness should be described as a 'top-down' emotion regulation strategy, while others suggest that mindfulness should be described as a 'bottom-up' emotion regulation strategy. Current discrepancies might derive from the many different descriptions and applications of mindfulness. The present review aims to discuss current descriptions of mindfulness and the relationship existing between mindfulness practice and most commonly investigated emotion regulation strategies. Recent results from functional neuro-imaging studies investigating mindfulness training within the context of emotion regulation are presented. We suggest that mindfulness training is associated with 'top-down' emotion regulation in short-term practitioners and with 'bottom-up' emotion regulation in long-term practitioners. Limitations of current evidence and suggestions for future research on this topic are discussed.

Brain on stress: how the social environment gets under the skin

Stress is a state of the mind, involving both brain and body as well as their interactions; it differs among individuals and reflects not only major life events but also the conflicts and pressures of daily life that alter physiological systems to produce a chronic stress burden that, in turn, is a factor in the expression of disease. This burden reflects the impact of not only life experiences but also genetic variations and individual health behaviors such as diet, physical activity, sleep, and substance abuse; it also reflects stable epigenetic modifications in development that set lifelong patterns of physiological reactivity and behavior through biological embedding of early environments interacting with cumulative change from experiences over the lifespan. Hormones associated with the chronic stress burden protect the body in the short run and promote adaptation (allostasis), but in the long run, the burden of chronic stress causes changes in the brain and body that can lead to disease (allostatic load and overload). Brain circuits are plastic and remodeled by stress to change the balance between anxiety, mood control, memory, and decision making. Such changes may have adaptive value in particular contexts, but their persistence and lack of reversibility can be maladaptive. However, the capacity of brain plasticity to effects of stressful experiences in adult life has only begun to be explored along with the efficacy of top-down strategies for helping the brain change itself, sometimes aided by pharmaceutical agents and other treatments.

Cortical thickness, mental absorption and meditative practice: possible implications for disorders of attention

Mental training techniques rooted in meditation are associated with attention improvement, increased activation and cortical thickening of attention/executive-related brain areas. Interestingly, attention-deficit/hyperactivity disorder (ADHD) is associated with behavioural deficits, hypo-activation and cortical thinning of similar networks. This study assessed the relationship between prior meditative training, attentional absorption, and cortical thickness. Grey matter thickness was measured in 18 meditators and 18 controls. Subjective reports of attentional absorption were modestly higher in meditators and across the entire sample correlated positively with cortical thickness in several regions corresponding to cingulo-fronto-parietal attention networks. Within these regions the meditation group had greater cortical thickness which was positively related to the extent of prior training. Evidence suggesting that meditative practice activates these cortical areas, improves attention and may ameliorate symptoms of ADHD by targeting vulnerable brain regions is discussed.

A pilot study of the effects of meditation on regional brain metabolism in distressed dementia caregivers

AIMS: Caregiver distress can affect mood and cognition. Meditation can be used to reduce stress. This pilot study explored whether yogic meditation could change regional cerebral metabolism in distressed caregivers. METHODS: Nine dementia caregivers were randomized to undergo meditation training compared with relaxation for 12 min per day for 8 weeks. Caregivers received neuropsychiatric assessments and brain FDG-PET scans at baseline and postintervention. RESULTS: The groups did not differ on measures of mood, mental and physical health, and burden at baseline and follow-up. When comparing the regional cerebral metabolism between groups, significant differences over time were found in the bilateral cerebellum (p < 0.0005), right inferior lateral anterior temporal (p < 0.0005), right inferior frontal (p = 0.001), left superior frontal (p = 0.001), left associative visual (p = 0.002) and right posterior cingulate (p = 0.002) cortices. CONCLUSION: Meditation practice in distressed caregivers resulted in different patterns of regional cerebral metabolism from relaxation. These pilot results should be replicated in a larger study.

The structure of mindful brain

Mindfulness is currently attracting a great deal of attention as a psychotherapy technique. It is defined as bringing one's complete attention to the experiences occurring in the present moment in a nonjudgmental or accepting way. The Five Facet Mindfulness Questionnaire (FFMQ) was developed to assess individual differences in mindfulness states. The FFMQ is composed of five facets representing elements of mindfulness: non-reactivity to inner experience, non-judging, acting with awareness, describing, and observing. In the present study, we applied voxel-based morphometry to investigate the relationship between the brain structure and each facet as measured by the FFMQ. The results showed a positive association between the describing facet of mindfulness on the FFMQ and gray matter volume in the right anterior insula and the right amygdala. In conclusion, mindfulness was related with development in parts of the somatic marker circuit of the brain.

The ever-changing brain: cellular and molecular mechanisms for the effects of stressful experiences

The adult brain is capable of considerable structural and functional plasticity and the study of hormone actions in brain has contributed to our understanding of this important phenomenon. In particular, stress and stress-related hormones such as glucocorticoids and mineralocorticoids play a key role in the ability of acute and chronic stress to cause reversible remodeling of neuronal connections in the hippocampus, prefrontal cortex, and amygdala. To produce this plasticity, these hormones act by both genomic and non-genomic mechanisms together with ongoing, experience-driven neural activity mediated by excitatory amino acid neurotransmitters, neurotrophic factors such as brain derived neurotrophic factor, extracellular molecules such as neural cell adhesion molecule, neuropeptides such as corticotrophin releasing factor, and endocannabinoids. The result is a dynamic brain architecture that can be modified by experience. Under this view, the role of pharmaceutical agents, such as antidepressants, is to facilitate such plasticity that must also be guided by experiences.

The effects of mindfulness-based cognitive therapy on affective memory recall dynamics in depression: a mechanistic model of rumination

OBJECTIVES

converging research suggests that mindfulness training exerts its therapeutic effects on depression by reducing rumination. Theoretically, rumination is a multifaceted construct that aggregates multiple neurocognitive aspects of depression, including poor executive control, negative and overgeneral memory bias, and persistence or stickiness of negative mind states. Current measures of rumination, most-often self-reports, do not capture these different aspects of ruminative tendencies, and therefore are limited in providing detailed information about the mechanisms of mindfulness.

METHODS

we developed new insight into the potential mechanisms of rumination, based on three model-based metrics of free recall dynamics. These three measures reflect the patterns of memory retrieval of valenced information: the probability of first recall (Pstart) which represents initial affective bias, the probability of staying with the same valence category rather than switching, which indicates strength of positive or negative association networks (Pstay), and probability of stopping (Pstop) or ending recall within a given valence, which indicates persistence or stickiness of a mind state. We investigated the effects of Mindfulness-Based Cognitive Therapy (MBCT; N = 29) vs. wait-list control (N = 23) on these recall dynamics in a randomized controlled trial in individuals with recurrent depression. Participants completed a standard laboratory stressor, the Trier Social Stress Test, to induce negative mood and activate ruminative tendencies. Following that, participants completed a free recall task consisting of three word lists. This assessment was conducted both before and after treatment or wait-list.

RESULTS

while MBCT participant's Pstart remained relatively stable, controls showed multiple indications of depression-related deterioration toward more negative and less positive bias. Following the intervention, MBCT participants decreased in their tendency to sustain trains of negative words and increased their tendency to sustain trains of positive words. Conversely, controls showed the opposite tendency: controls stayed in trains of negative words for longer, and stayed in trains of positive words for less time relative to pre-intervention scores. MBCT participants tended to stop recall less often with negative words, which indicates less persistence or stickiness of negatively valenced mental context.

CONCLUSION

MBCT participants showed a decrease in patterns that may perpetuate rumination on all three types of recall dynamics (Pstart, Pstay, and Pstop), compared to controls. MBCT may weaken the strength of self-perpetuating negative associations networks that are responsible for the persistent and "sticky" negative mind states observed in depression, and increase the positive associations that are lacking in depression. This study also offers a novel, objective method of measuring several indices of ruminative tendencies indicative of the underlying mechanisms of rumination.

Influence of mindfulness practice on cortisol and sleep in long-term and short-term meditators

BACKGROUND

There is growing scientific interest in assessing the biological correlates of non-pharmacological interventions such as mindfulness. Examinations of the beneficial effects of mindfulness on hypothalamus-pituitary-adrenocortical system activity (HPA SA) and sleep are sparse. The aim of the present study was to explore the impact of long- and short-term meditation experience on HPA SA and sleep.

METHOD

There were 20 participants, 9 of whom had long-term experience in meditation (mean = 264 months) and 11 novices. Novices underwent an 8-week course in Mindfulness-Based Stress Reduction (MBSR), and cortisol samples were taken in the lab at the beginning and end of the course. To assess the cortisol awakening response, 4 morning cortisol samples were collected. Sleep and mindfulness were assessed by self-rating questionnaires.

RESULTS

Among participants with long-term meditation experience, morning cortisol decreased with length of experience. For novices, after an 8-week introductory MBSR course, morning cortisol levels had decreased, while both sleep and self-attribution of mindfulness significantly improved. Cortisol levels did not, however, change between the beginning and end of individual MBSR sessions.

CONCLUSIONS

The pattern of results lends support to the view that MBSR/meditation has a favorable influence both on biomarkers of stress regulation, such as cortisol secretion, and on sleep.