Effects of a mindfulness based behavioral intervention for young adults with childhood maltreatment history on hippocampal morphometry: a pilot MRI study with voxel-based morphometry

Neural correlates of reduction in self-judgment after mindful self-compassion training: A pilot study with resting state fMRI

Self-judgment is a trans-diagnostic symptom among various psychological disorders, therefore can be a therapeutic target for many common psychiatric conditions. Self-judgment often arises among those who experienced childhood maltreatment, which increases the risk for developing comorbid psychiatric disorders that are resistant to traditional pharmacological and psychological interventions. Understanding the neural correlates of the therapeutic effect of behavioral interventions for reducing self-judgment is key for developing and refining evidence-based intervention programs. This single arm pilot study (N = 24) explored the neural correlates of reduction in self-judgment after an eight-week mindful self-compassion (MSC) intervention program for a sample of adult patients with either anxiety or depressive disorders, with 83 % having more than one diagnoses. The results demonstrated significant reduction of self-judgment after the intervention (p < 0.001, d = -1.04) along with increased self-compassion (p < 0.001, d =1.20); in particular, participants with above median score on the Childhood Trauma Questionnaire had significantly more improvement than those with below median scores (p < 0.05). Resting state fMRI was used to study neural correlates and showed that reduced self-judgment was associated with increased posterior cingulate cortex functional connectivity with dorsal lateral prefrontal cortex, inferior frontal gyrus, and dorsal medial prefrontal cortex, accompanied by reduced posterior cingulate cortex functional connectivity with the amygdala-hippocampal complex. These findings suggest reduced self-judgment after MSC training was substantiated by reduced fear circuitry influences on self-referential processes along with enhanced frontal regulation from the executive network and language network.

Temporal dynamics and long-term effects of a mindfulness-based intervention for young adults with adverse childhood experiences

Objectives

Mindfulness-based interventions (MBIs) have been shown to be beneficial for young adults with adverse childhood experiences (ACE), but the temporal course of the therapeutic effects is still not well understood. This study aimed to investigate MBI-induced weekly changes and long-term effects in trait mindfulness and psychological symptoms.

Method

This study analyzed longitudinal data from a mechanistic clinical trial in which young adults (aged 21-35) with ACE were randomized to an 8-week MBI or an active control condition of Stress Management Education (SME), with 21 and 19 completers respectively. Mindful Attention Awareness Scale (MAAS), Perceived Stress Scale (PSS), and Kellner's Symptom Questionnaire (KSQ) were administered before, after, and weekly during the 8-week interventions, and at 6-, 12-, and 18-months follow-up. Data analyses were conducted with linear mixed effects models, Granger causality and Dynamic Structural Equation Modeling (DSEM).

Results

Group by time interaction effects were observed with PSS, MAAS, KSQ-depression, KSQ-hostility, and KSQ-anxiety with small effect sizes. Only in the MBI group, increases of MAAS scores predicted reductions of PSS, KSQ-somatization, and KSQ-hostility scores. MAAS score reached significant increase at the end of MBI, and most MBI-induced symptom reduction lasted 12 months without refresher courses.

Conclusions

MBI demonstrated unique effects of trait mindfulness improvement leading to psychological symptom reductions. At least 8 weeks of MBI program duration and refreshment at 12 months may be necessary for ACE survivors.

Preregistration

This study is not preregistered.

Smaller hippocampal volume is associated with anxiety symptoms in high-risk Black youth

Although there is an established link between smaller hippocampal volume and anxiety, the longitudinal relations between hippocampus structure and anxiety in diverse youth are not well understood. The present longitudinal study investigated hippocampal volumes related to anxiety symptoms in a sample of Black 8-14-year-old youth (N = 64), a population historically underrepresented in neuroimaging research. Smaller hippocampal volumes were associated with greater anxiety symptoms independent of age, sex, intracranial volume and trauma exposure. Exploratory longitudinal analyses showed smaller hippocampal volume as a predictor for anxiety symptoms (n = 37) and not a consequence of anxiety symptoms (n = 32), however results were inconclusive as this finding was no longer significant after correcting for baseline anxiety symptoms. Overall, this data increases our understanding of potential neurobiological mechanisms for anxiety in a high-risk sample of Black youth and suggests future directions into studying trajectories of developmental risk.

Beneficial effects of mindfulness-based intervention on hippocampal volumes and episodic memory for childhood adversity survivors

Background

Adverse Childhood Experience (ACE) has detrimental impacts on neural development, especially hippocampal morphometry. Mindfulness-Based Interventions (MBI) has been shown to induce adaptive hippocampal changes especially at the subiculum. The present study aims to investigate the effects of MBI on subiculum volumes among ACE survivors, as well as the effects on episodic memory as a probe into hippocampal functionality.

Methods

We analyzed anatomical MRI data and performance indices from an episodic memory task called the Mnemonic Similarity Task (MST) collected from a randomized controlled longitudinal study that compared an 8-week MBI (N = 20) to an active control condition of Stress Management Education (SME) (N = 19). FreeSurfer 6.0 was used for automated hippocampal subfield segmentation and volumetric estimation.

Results

Significant group differences were observed with the volumetric changes of the right whole hippocampus and right subiculum. Only the MBI group showed improved pattern separation capability from MST, which was associated with stress reduction and right subiculum volumetric changes.

Limitations

Modest sample size. MST task was performed outside of MRI.

Conclusions

These findings suggest beneficial effects of MBI for hippocampal volumes and episodic memory, while highlighting the importance of the subiculum for MBI-induced neural and cognitive changes. The subiculum's known role in inhibitory control was interpreted as a potential mechanism for it to exhibit MBI-induced volumetric changes, which sheds light on the potential neural underpinnings of mindfulness meditation for reducing stress reactivity among ACE survivors.

The neurobiological effects of childhood maltreatment on brain structure, function, and attachment

Childhood maltreatment is a risk factor for psychopathologies, and influences brain development at specific periods, particularly during early childhood and adolescence. This narrative review addresses phenotypic alterations in sensory systems associated with specific types of childhood maltreatment exposure, periods of vulnerability to the neurobiological effects of maltreatment, and the relationships between childhood maltreatment and brain structure, function, connectivity, and network architecture; psychopathology; and resilience. It also addresses neurobiological alterations associated with maternal communication and attachment disturbances, and uses laboratory-based measures during infancy and case-control studies to elucidate neurobiological alterations in reactive attachment disorders in children with maltreatment histories. Moreover, we review studies on the acute effects of oxytocin on reactive attachment disorder and maltreatment and methylation of oxytocin regulatory genes. Epigenetic changes may play a critical role in initiating or producing the atypical structural and functional brain alterations associated with childhood maltreatment. However, these changes could be reversed through psychological and pharmacological interventions, and by anticipating or preventing the emergence of brain alterations and subsequent psychopathological risks.

Neural correlates of mindfulness meditation and hypnosis on magnetic resonance imaging: similarities and differences. A scoping review

BACKGROUND

Mindfulness meditation (MM) and hypnosis practices are gaining interest in mental health, but their physiological mechanisms remain poorly understood. This study aimed to synthesize the functional, morphometric and metabolic changes associated with each practice using magnetic resonance imaging (MRI), and to identify their similarities and differences.

METHODS

MRI studies investigating MM and hypnosis in mental health, specifically stress, anxiety, and depression, were systematically screened following PRISMA guidelines from four research databases (PubMed, Web of Science, Embase, PsycINFO) between 2010 and 2022.

RESULTS

In total, 97 references met the inclusion criteria (84 for MM and 13 for hypnosis). This review showed common and divergent points regarding the regions involved and associated brain connectivity during MM practice and hypnosis. The primary commonality between mindfulness and hypnosis was decreased default mode network intrinsic activity and increased central executive network - salience network connectivity. Increased connectivity between the default mode network and the salience network was observed in meditative practice and mindfulness predisposition, but not in hypnosis.

CONCLUSIONS

While MRI studies provide a better understanding of the neural basis of hypnosis and meditation, this review underscores the need for more rigorous studies.

Practitioner Review: Neurobiological consequences of childhood maltreatment - clinical and therapeutic implications for practitioners

BACKGROUND

Childhood maltreatment is one of the most important preventable risk factors for a wide variety of psychiatric disorders. Further, when psychiatric disorders emerge in maltreated individuals they typically do so at younger ages, with greater severity, more psychiatric comorbid conditions, and poorer response to established treatments, resulting in a more pernicious course with an increased risk for suicide. Practitioners treating children, adolescents, and young adults with psychiatric disorders will likely encounter the highest prevalence of clients with early-onset maltreatment-associated psychiatric disorders. These may be some of their most challenging cases.

METHOD

In this report, we explore key validated alterations in brain structure, function, and connectivity associated with exposure to childhood maltreatment as potential mechanisms behind their patients' clinical presentations.

RESULTS

We then summarize key behavioral presentations likely associated with neurobiological alterations and propose a toolkit of established trauma and skills-based strategies that may help diminish symptoms and foster recovery. We also discuss how some of these alterations may serve as latent vulnerability factors for the possible development of future psychopathology.

CONCLUSIONS

Research on the neurobiological consequences of childhood adversity provides a vastly enriched biopsychosocial understanding of the developmental origins of health and pathology that will hopefully lead to fundamental advances in clinical psychology and psychiatry.

Childhood adversity severity modulates the associations between adaptive psychological changes and amygdala volumetric changes in response to behavioral interventions

Background

Adverse Childhood Experience (ACE) has been shown to have detrimental impact on amygdala structure. Prior research found that adaptive psychological changes after Mindfulness-Based Interventions (MBI) were associated with amygdala volumetric changes. The present study aims to further investigate whether such effects also occur among ACE survivors and whether the effects are unique to MBI.

Methods

A total of 64 young adult childhood adversity survivors were randomized to an eight-week MBI or Stress Management Education (SME) as an active control condition. Anatomical MRI and questionnaires on mindfulness, stress and psychological health were collected at baseline and post-intervention. Due to subject dropout, the final sample included 39 subjects (MBI:20, SME:19).

Results

Both groups showed increased mindfulness levels, reduced stress, and improved psychological symptoms (depression, anxiety, and somatization), with no significant group by time interaction effect. There was no significant group difference on amygdala volumetric changes. Within the MBI group, childhood maltreatment severity was a significant mediator between changes of mindfulness levels and right amygdala volumetric changes. Across pooled sample of both groups, childhood maltreatment was a significant moderator for the effect of trait anxiety level changes on left amygdala volumetric changes.

Limitations

Modest sample size, relatively low retention rates, suboptimal monitoring of home practice.

Conclusions

MBI did not demonstrate overall better clinical effects than SME. Psychological-change-dependent amygdala volumetric change was not specific to MBI. Childhood maltreatment severity modulated the relationships between adaptive psychological changes and amygdala volumetric changes.

There Is More to Mindfulness Than Emotion Regulation: A Study on Brain Structural Networks

Dispositional mindfulness and emotion regulation are two psychological constructs closely interrelated, and both appear to improve with the long-term practice of mindfulness meditation. These constructs appear to be related to subcortical, prefrontal, and posterior brain areas involved in emotional processing, cognitive control, self-awareness, and mind wandering. However, no studies have yet discerned the neural basis of dispositional mindfulness that are minimally associated with emotion regulation. In the present study, we use a novel brain structural network analysis approach to study the relationship between structural networks and dispositional mindfulness, measured with two different and widely used instruments [Mindfulness Attention Awareness Scale (MAAS) and Five Facet Mindfulness Questionnaire (FFMQ)], taking into account the effect of emotion regulation difficulties. We observed a number of different brain regions associated with the different scales and dimensions. The total score of FFMQ and MAAS overlap with the bilateral parahippocampal and fusiform gyri. Additionally, MAAS scores were related to the bilateral hippocampus and the FFMQ total score to the right insula and bilateral amygdala. These results indicate that, depending on the instrument used, the characteristics measured could differ and could also involve different brain systems. However, it seems that brain areas related to emotional reactivity and semantic processing are generally related to Dispositional or trait mindfulness (DM), regardless of the instrument used.

A pilot study on amygdala volumetric changes among young adults with childhood maltreatment histories after a mindfulness intervention

The amygdala morphometry is highly sensitive to stress and is implicated in various psychopathologies that are common among individuals with childhood maltreatment histories. This pilot study investigated bilateral amygdala volumetric changes among 15 young adults with childhood maltreatment histories undergoing an eight-week mindfulness intervention compared to 19 matched participants in a waitlist control group. Results indicated significant cross-individual variability in amygdala volumetric changes after the intervention, which resulted in no significant group by time interaction effect. Degree and direction of changes in right amygdala volume correlated with baseline volumes, with larger than average right amygdala showing an increase in volume and smaller amygdala a decrease. Increasing right amygdala volume was also associated with higher intervention compliance, and a greater increase in self-compassion. Increasing left amygdala volume was associated with more reduction in perceived stress, rejection sensitivity and interpersonal distress. Findings from the present study highlight the importance of investigating individual variability and its contributing factors in future studies on neural responses of mindfulness interventions, as well as the distinct responses of the left and right amygdala.