Interdependent self-construal predicts increased gray matter volume of scene processing regions in the brain.

Interdependent self-construal (SC) is thought to lead to a more holistic cognitive style that emphasizes the processing of the background scene of a focal object. At present, little is known about whether the structural properties of the brain might underlie this functional relationship. Here, we examined the gray matter (GM) volume of three cortical regions involved in scene processing -- a cornerstone of contextual processing. Study 1 tested 78 European American non-student adults and found that interdependent (vs. independent) SC predicts higher GM volume in the parahippocampal place area (PPA), one of the three target regions. Testing both European American and East Asian college students (total N = 126), Study 2 replicated this association. Moreover, the GM volume of all the three target regions was greater for East Asians than for European Americans. Our findings suggest that there is a structural neural underpinning for the cultural variation in cognitive style.

A neurobehavioral account for decentering as the salve for the distressed mind.

Distress is commonly characterized by prolonged internal suffering that can range from self-focused processing of negative emotions and stressors, to highly intensely aversive and prolonged emotional states, thereby, worsening or complicating emotional and physical conditions. Decentering represents a metacognitive capacity thought to reflect three interrelated processes: meta-awareness, disidentification from internal experience, and reduced reactivity to thought content-which is reliably increased with mindfulness-based interventions. In this essay, we seek to link the clinical presentation of distress disorders to known or hypothesized disruptions in neural networks that underlie emotion, cognition, and goal directed behavior, and offer a neurobehavioral account for how and why treatments imbued with mindfulness meditation might ameliorate these conditions, in part through increases in decentering.

Smaller Hippocampal Volume in Posttraumatic Stress Disorder: A Multisite ENIGMA-PGC Study: Subcortical Volumetry Results From Posttraumatic Stress Disorder Consortia.

BACKGROUND: Many studies report smaller hippocampal and amygdala volumes in posttraumatic stress disorder (PTSD), but findings have not always been consistent. Here, we present the results of a large-scale neuroimaging consortium study on PTSD conducted by the Psychiatric Genomics Consortium (PGC)-Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) PTSD Working Group. METHODS: We analyzed neuroimaging and clinical data from 1868 subjects (794 PTSD patients) contributed by 16 cohorts, representing the largest neuroimaging study of PTSD to date. We assessed the volumes of eight subcortical structures (nucleus accumbens, amygdala, caudate, hippocampus, pallidum, putamen, thalamus, and lateral ventricle). We used a standardized image-analysis and quality-control pipeline established by the ENIGMA consortium. RESULTS: In a meta-analysis of all samples, we found significantly smaller hippocampi in subjects with current PTSD compared with trauma-exposed control subjects (Cohen's d = -0.17, p = .00054), and smaller amygdalae (d = -0.11, p = .025), although the amygdala finding did not survive a significance level that was Bonferroni corrected for multiple subcortical region comparisons (p < .0063). CONCLUSIONS: Our study is not subject to the biases of meta-analyses of published data, and it represents an important milestone in an ongoing collaborative effort to examine the neurobiological underpinnings of PTSD and the brain's response to trauma.

A Pilot Study of Mindfulness-Based Exposure Therapy in OEF/OIF Combat Veterans with PTSD: Altered Medial Frontal Cortex and Amygdala Responses in Social-Emotional Processing.

Combat-related posttraumatic stress disorder (PTSD) is common among returning veterans, and is a serious and debilitating disorder. While highly effective treatments involving trauma exposure exist, difficulties with engagement and early drop may lead to sub-optimal outcomes. Mindfulness training may provide a method for increasing emotional regulation skills that may improve engagement in trauma-focused therapy. Here, we examine potential neural correlates of mindfulness training and in vivo exposure (non-trauma focused) using a novel group therapy [mindfulness-based exposure therapy (MBET)] in Afghanistan (OEF) or Iraq (OIF) combat veterans with PTSD. OEF/OIF combat veterans with PTSD (N = 23) were treated with MBET (N = 14) or a comparison group therapy [Present-centered group therapy (PCGT), N = 9]. PTSD symptoms were assessed at pre- and post-therapy with Clinician Administered PTSD scale. Functional neuroimaging (3-T fMRI) before and after therapy examined responses to emotional faces (angry, fearful, and neutral faces). Patients treated with MBET had reduced PTSD symptoms (effect size d = 0.92) but effect was not significantly different from PCGT (d = 0.43). Improvement in PTSD symptoms from pre- to post-treatment in both treatment groups was correlated with increased activity in rostral anterior cingulate cortex, dorsal medial prefrontal cortex (mPFC), and left amygdala. The MBET group showed greater increases in amygdala and fusiform gyrus responses to Angry faces, as well as increased response in left mPFC to Fearful faces. These preliminary findings provide intriguing evidence that MBET group therapy for PTSD may lead to changes in neural processing of social-emotional threat related to symptom reduction.

ALTERED DEFAULT MODE NETWORK (DMN) RESTING STATE FUNCTIONAL CONNECTIVITY FOLLOWING A MINDFULNESS-BASED EXPOSURE THERAPY FOR POSTTRAUMATIC STRESS DISORDER (PTSD) IN COMBAT VETERANS OF AFGHANISTAN AND IRAQ.

BACKGROUND: Recent studies suggest that mindfulness may be an effective component for posttraumatic stress disorder (PTSD) treatment. Mindfulness involves practice in volitional shifting of attention from "mind wandering" to present-moment attention to sensations, and cultivating acceptance. We examined potential neural correlates of mindfulness training using a novel group therapy (mindfulness-based exposure therapy (MBET)) in combat veterans with PTSD deployed to Afghanistan (OEF) and/or Iraq (OIF). METHODS: Twenty-three male OEF/OIF combat veterans with PTSD were treated with a mindfulness-based intervention (N = 14) or an active control group therapy (present-centered group therapy (PCGT), N = 9). Pre-post therapy functional magnetic resonance imaging (fMRI, 3 T) examined resting-state functional connectivity (rsFC) in default mode network (DMN) using posterior cingulate cortex (PCC) and ventral medial prefrontal cortex (vmPFC) seeds, and salience network (SN) with anatomical amygdala seeds. PTSD symptoms were assessed at pre- and posttherapy with Clinician Administered PTSD Scale (CAPS). RESULTS: Patients treated with MBET had reduced PTSD symptoms (effect size d = 0.92) but effect was not significantly different from PCGT (d = 0.46). Increased DMN rsFC (PCC seed) with dorsolateral dorsolateral prefrontal cortex (DLPFC) regions and dorsal anterior cingulate cortex (ACC) regions associated with executive control was seen following MBET. A group × time interaction found MBET showed increased connectivity with DLPFC and dorsal ACC following therapy; PCC-DLPFC connectivity was correlated with improvement in PTSD avoidant and hyperarousal symptoms. CONCLUSIONS: Increased connectivity between DMN and executive control regions following mindfulness training could underlie increased capacity for volitional shifting of attention. The increased PCC-DLPFC rsFC following MBET was related to PTSD symptom improvement, pointing to a potential therapeutic mechanism of mindfulness-based therapies.

Biological and symptom changes in posttraumatic stress disorder treatment: a randomized clinical trial.

BACKGROUND: Understanding cognitive and biological mechanisms of PTSD treatment can help refine treatments and increase rates of response. METHODS: Thirty-six veterans with PTSD were randomly assigned to receive Prolonged exposure therapy (PE) or Present-Centered therapy (PCT). We examined symptoms, trauma-related cognitions, and two indices of HPA axis function (cortisol awakening response and cortisol response to a script-driven imagery task). RESULTS: Thirty veterans started treatment and 26 completed. PE resulted in significantly more symptom reduction than PCT (P = .008). High treatment responders collapsed across treatments showed nominally higher cortisol levels measured at pretreatment 30 min after trauma script exposure compared to low responders (P = .08). At midtreatment, high treatment responders showed higher cortisol levels throughout the imagery task (Ps = .03-.04). There were no differences between high and low treatment responders at posttreatment. Thoughts of incompetence (F (1.6, 35.8) = 16.8, P = .000) and a dangerous world (F (1.3, 29.9) = 8.2, P = .004) significantly improved over time in high treatment responders but showed no change in low responders. Script-associated cortisol response prior to treatment and reductions in thoughts of incompetence accounted for 83% of the variance in reductions in PTSD severity with PE. CONCLUSIONS: Both increased cortisol response to personal trauma script prior to PTSD therapy and reductions in cognitive symptoms of PTSD were significantly and uniquely related to reductions in the core symptoms of PTSD in PE. However, contrary to our hypotheses, cortisol measures were not related to cognitive changes.

A pilot study of group mindfulness-based cognitive therapy (MBCT) for combat veterans with posttraumatic stress disorder (PTSD).

BACKGROUND: "Mindfulness-based" interventions show promise for stress reduction in general medical conditions, and initial evidence suggests that they are accepted in trauma-exposed individuals. Mindfulness-based cognitive therapy (MBCT) shows substantial efficacy for prevention of depression relapse, but it has been less studied in anxiety disorders. This study investigated the feasibility, acceptability, and clinical outcomes of an MBCT group intervention adapted for combat posttraumatic stress disorder (PTSD). METHODS: Consecutive patients seeking treatment for chronic PTSD at a VA outpatient clinic were enrolled in 8-week MBCT groups, modified for PTSD (four groups, n = 20) or brief treatment-as-usual (TAU) comparison group interventions (three groups, n = 17). Pre and posttherapy psychological assessments with clinician administered PTSD scale (CAPS) were performed with all patients, and self-report measures (PTSD diagnostic scale, PDS, and posttraumatic cognitions inventory, PTCI) were administered in the MBCT group. RESULTS: Intent to treat analyses showed significant improvement in PTSD (CAPS (t(19) = 4.8, P < .001)) in the MBCT condition but not the TAU conditions, and a significant Condition × Time interaction (F[1,35] = 16.4, P < .005). MBCT completers (n = 15, 75%) showed good compliance with assigned homework exercises, and significant and clinically meaningful improvement in PTSD symptom severity on posttreatment assessment in CAPS and PDS (particularly in avoidance/numbing symptoms), and reduced PTSD-relevant cognitions in PTCI (self blame). CONCLUSIONS: These data suggest group MBCT as an acceptable brief intervention/adjunctive therapy for combat PTSD, with potential for reducing avoidance symptom cluster and PTSD cognitions. Further studies are needed to examine efficacy in a randomized controlled design and to identify factors influencing acceptability and efficacy.

Medial prefrontal cortex and right insula activity predict plasma ACTH response to trauma recall.

Neural substrates underlying psychological activation of the limbic-hypothalamic-pituitary-adrenal (LHPA) axis are not well understood in humans. Trauma recall (using autobiographical script-driven imagery) may provide a model to study neural circuitry involved in LHPA axis activation to personally threatening psychological stimuli. This study sought to identify brain activation patterns that differentiated combat veterans who mounted an LHPA response to trauma recall from those who did not. Twenty-five Vietnam combat veterans (14 with current PTSD, 11 with no PTSD history) experienced autobiographic script-driven imagery in an [(15)O] H(2)O positron emission tomography (PET) paradigm with recurrent blood sampling. Trauma recall elicited acute ACTH responses in some but not all veterans, regardless of the PTSD status and independent of emotional responses. ACTH responders (mean ACTH increase of 24+/-7 pg/ml, n=13) were compared to non-responders (mean decrease of -0.6+/-0.6 pg/ml, n=12) in regional cerebral blood flow (rCBF). Both groups activated right insula (BA13) in response to trauma recall. However, ACTH responders deactivated rostral mPFC (BA10)/rostral ACC (BA32), whereas non-responders activated this same mPFC region, and deactivated amygdala, hippocampus, and temporal pole. In group contrasts comparing ACTH responders to non-responders, the responders had significantly higher rCBF in right insula and right temporal pole, whereas non-responders had higher rCBF in rostral mPFC and dorsal ACC. These results support the hypotheses that right insula is involved in psychological activation of the LHPA axis and that rostral mPFC may negatively modulate LHPA axis responses.