Neuroimaging studies in post-traumatic stress disorder

Learning to forget: Hippocampal-amygdala connectivity partially mediates the effect of sexual trauma severity on verbal recall in older women undiagnosed with posttraumatic stress disorder

Verbal learning deficits are common among sexually traumatized women who have not been formally diagnosed with posttraumatic stress disorder (PTSD). Aberrant resting-state functional connectivity (rsFC) of the amygdala and hippocampus are implicated in PTSD and verbal memory impairment. We tested rsFC between bilateral dentate gyrus (DG) and both centromedial (CM) and basolateral (BL) nuclei of the amygdala as statistical mediators for the effect of sexual trauma-related symptom severity on delayed verbal recall performance in 63 older women (age: 60-85 years) undiagnosed with PTSD. Participant data were drawn from the NKI-Rockland Study. Individuals completed a 10-min resting-state scan, Rey Auditory Verbal Learning Test (RAVLT), and the Sexual Abuse Trauma Index (SATI) from the Trauma Symptom Checklist. Z-scores indicating rsFC of DG with BL and CM amygdala seeds were evaluated in two separate mediation models. Higher SATI scores were associated with lower RAVLT after controlling for age, β = -.23, 95% CI [.48, .03], p = .039. This effect was negated upon adding a negative path from SATI to rsFC of left DG and right CM, β = -.29, 95% CI [-.52, -.02], p = .022, and a positive path from that seed pair to RAVLT List A recall, β = .28, 95% CI [.03, 0.48], p = .015. Chi-square fit indices supported partial mediation by this seed pair, p = .762. In the absence of PTSD sexual trauma symptoms partially relate to verbal learning deficits as a function of aberrant rsFC between left hippocampus DG and right amygdala CM nuclei.

Early auditory-evoked potentials in body dysmorphic disorder: An ERP/sLORETA study

Body dysmorphic disorder (BDD) is characterized by excessive preoccupation with imagined or slight physical defects in appearance. BDD is associated with cognitive impairments (attention, visual processing). Our study aims to evaluate the early neural responses (N100, P200) to prepulse inhibition (PPI) and prepulse facilitation (PPF), to investigate attentional processing of BDD in the auditory domain. Fifty-five adults took part: 30 BDD patients and 25 healthy controls. We compared their brain responses to PPI and PPF by analyzing global field power (GFP), event-related potentials (ERPs) and their respective sources. BDD exhibited reduced N100 amplitudes compared to healthy controls in response to the startle tone elicited by both PPI and PPF, potentially suggesting impaired allocation of attention. Interestingly, the lower the GFP at the N100, the higher the BDD severity. Source reconstruction analysis showed reduced activation for BDD during the N100 time window in PPI. Scalp responses and source activations in PPI were decreased overall compared to PPF, confirming the gating effect of PPI. We provided evidence that the N100 may serve as an electrophysiological marker of BDD, predicting its severity. Our study demonstrated the potential of using ERPs combined with behavioural PPI and PPF protocols to advance our understanding of BDD pathophysiology.

High intensity interval training protects from Post Traumatic Stress Disorder induced cognitive impairment

This study aimed to show the possible protective effects of high intensity interval training (HIIT) in PTSD-induced rats and probable underlying mechanisms. Female rats (n = 44) were separated as; Sedentary (SED), moderate intensity continuous training (MICT), HIIT groups. Then the groups were divided into subgroups according to PTSD induction (n = 6-8/group). Exercise groups performed HIIT or MICT for 6 weeks. On the fifth week, PTSD was induced by single prolonged stress protocol. Cognitive functions were evaluated by object recognition, anxiety levels by hole-board and elevated plus maze, and fear conditioning by passive avoidance tests. Following decapitation, malondialdehyde (MDA), glutathione (GSH), luminol and lucigenin chemiluminescence levels, and myeloperoxidase (MPO), superoxide dismutase (SOD) and catalase (CAT) activities were measured, and histopathological damage was evaluated. The data was analyzed by one-way ANOVA. Cognitive decline and aggravated anxiety levels in SED + PTSD group were improved in both PTSD-induced exercise groups (p < 0.05-0.001). The increased chemiluminescence levels, MPO activity and histological damage were depressed in both PTSD-induced exercise groups (p < 0.05-0.001). The risen MDA levels in SED + PTSD group were suppressed only in HIIT + PTSD group (p < 0.01-0.001). The decreased GSH levels were increased by MICT (p < 0.05-0.001), and CAT and SOD activities were improved via HIIT (p < 0.05). Compared to SED group, latency was decreased in SED + PTSD (p < 0.05-0.01) group. Neuronal damage scores were alleviated in both PTSD-induced exercise groups (p < 0.001). PTSD-induced memory decline was protected by both of the exercise models however more effectively by HIIT via decreasing oxidative stress, anxiety levels and by improving antioxidant capacity as a protective system for neuronal damage.

The Utility of Event-Related Potentials in Clinical Psychology

Event-related potentials (ERPs) are direct measures of brain activity that can be leveraged for clinically meaningful research. They can relate robustly both to continuous measures of individual difference and to categorical diagnoses in ways that clarify similarities and distinctions between apparently related disorders and traits. ERPs can be linked to genetic risk, can act as moderators of developmental trajectories and responses to stress, and can be leveraged to identify those at greater risk for psychopathology, especially when used in combination with other neural and self-report measures. ERPs can inform models of the development of, and risk for, psychopathology. Finally, ERPs can be used as targets for existing and novel interventions and prevention efforts. We provide concrete examples for each of these possibilities by focusing on programmatic research on the error-related negativity and anxiety, and thus show that ERPs are poised to make greater contributions toward the identification, prediction, treatment, and prevention of mental disorders.

Timing is everything: differential effects of chronic stress on fear extinction

RATIONALE

Stress disorders cause abnormal regulation of fear-related behaviors. In most rodent models of these effects, stress was administered before fear conditioning, thereby assessing its impact on both the formation and extinction of fear memories, not the latter alone. Here, we dissociated the two processes by also administering stress after fear conditioning, and then compared how pre-conditioning versus post-conditioning exposure to chronic stress affects subsequent acquisition and recall of fear extinction.

METHODS

Male Wistar rats were subjected to chronic immobilization stress (2 h/day, 10 days); the morphological effects of which were analyzed using modified Golgi-Cox staining across brain areas mediating the formation and extinction of fear memories. Separate groups of rats underwent fear conditioning followed by acquisition and recall of extinction, wherein stress was administered either before or after fear conditioning.

RESULTS

When fear memories were formed after chronic stress, both acquisition and retrieval of extinction was impaired. Strikingly, these deficits were absent when fear memories were formed before the same stress. Chronic stress also reduced dendritic spine density in the infralimbic prefrontal cortex, but enhanced it in the basolateral amygdala.

CONCLUSION

Chronic stress, administered either before or after fear learning, had distinct effects on the acquisition and recall of fear extinction memories. Stress also strengthened the structural basis of synaptic connectivity in the amygdala, but weakened it in the prefrontal cortex. Thus, despite eliciting a specific pattern of brain region-specific morphological changes, the timing of the same stress gave rise to strikingly different behavioral effects on the extinction of fear.

A Neuroscience-Oriented Research Approach to Borderline Personality Disorder

Traditionally, the study of personality disorders had been based on psychoanalytic or behavioral models. Over the past two decades, there has been an emerging neuroscience model of borderline personality disorder (BPD) grounded in the concept of BPD as a condition in which dysfunctional neural circuits underlie its pathological dimensions, some of which include emotion dysregulation (broadly encompassing affective instability, negative affectivity, and hyperarousal), abnormal interpersonal functioning, and impulsive aggression. This article, initiated at a joint Columbia University- Cornell University Think Tank on BPD with representation from the Icahn School of Medicine at Mount Sinai, suggests how to advance research in BPD by studying the dimensions that underlie BPD in addition to studying the disorder as a unitary diagnostic entity. We suggest that linking the underlying neurobiological abnormalities to behavioral symptoms of the disorder can inform a research agenda to better understand BPD with its multiple presentations.

From Stress to Anhedonia: Molecular Processes through Functional Circuits

Converging evidence across species highlights the contribution of environmental stress to anhedonia (loss of pleasure and/or motivation). However, despite a clear link between stress and the emergence of anhedonic-like behavior in both human and animal models, the underlying biological pathways remain elusive. Here, we synthesize recent findings across multiple levels, from molecular signaling pathways through whole-brain networks, to discuss mechanisms through which stress may influence anhedonia. Recent work suggests the involvement of diverse systems that converge on the mesolimbic reward pathway, including medial-prefrontal cortical circuitry, neuroendocrine stress responses, homeostatic energy regulation systems, and inflammation. We conclude by emphasizing the need to disentangle the influences of key dimensions of stress on specific aspects of reward processing, taking into account individual differences that could moderate this relationship.

Disrupted cortical brain network in post-traumatic stress disorder patients: a resting-state electroencephalographic study

This study aimed to examine the source-level cortical brain networks of post-traumatic stress disorder (PTSD) based on the graph theory using electroencephalography (EEG). Sixty-six cortical source signals were estimated from 78 PTSD and 58 healthy controls (HCs) of resting-state EEG. Four global indices (strength, clustering coefficient (CC), path length (PL) and efficiency) and one nodal index (CC) were evaluated in six frequency bands (delta, theta, alpha, low beta, high beta and gamma). PTSD showed decreased global strength, CC and efficiency, in delta, theta, and low beta band and enhanced PL in theta and low beta band. In low beta band, the strength and CC correlated positively with the anxiety scores, while PL had a negative correlation. In addition, nodal CCs were reduced in PTSD in delta, theta and low beta band. Nodal CCs of theta band correlated negatively with rumination and re-experience symptom scores; while, nodal CCs in low beta band correlated positively with anxiety and pain severity. Inefficiently altered and symptom-dependent changes in cortical networks were seen in PTSD. Our source-level cortical network indices might be promising biomarkers for evaluating PTSD.

Long-Term Effects of Acute Stress on the Prefrontal-Limbic System in the Healthy Adult

Most people are exposed to at least one traumatic event during the course of their lives, but large numbers of people do not develop posttraumatic stress disorders. Although previous studies have shown that repeated and chronic stress change the brain’s structure and function, few studies have focused on the long-term effects of acute stressful exposure in a nonclinical sample, especially the morphology and functional connectivity changes in brain regions implicated in emotional reactivity and emotion regulation. Forty-one months after the 5/12 Wenchuan earthquake, we investigated the effects of trauma exposure on the structure and functional connectivity of the brains of trauma-exposed healthy individuals compared with healthy controls matched for age, sex, and education. We then used machine-learning algorithms with the brain structural features to distinguish between the two groups at an individual level. In the trauma-exposed healthy individuals, our results showed greater gray matter density in prefrontal-limbic brain systems, including the dorsal anterior cingulate cortex, medial prefrontal cortex, amygdala and hippocampus, than in the controls. Further analysis showed stronger amygdala-hippocampus functional connectivity in the trauma-exposed healthy compared to the controls. Our findings revealed that survival of traumatic experiences, without developing PTSD, was associated with greater gray matter density in the prefrontal-limbic systems related to emotional regulation.

24-hour-restraint stress induces long-term depressive-like phenotypes in mice

There is an increasing risk of mental disorders, such as acute stress disorder (ASD), post-traumatic stress disorder (PTSD) and depression among survivors who were trapped in rubble during earthquake. Such long-term impaction of a single acute restraint stress has not been extensively explored. In this study, we subjected mice to 24-hour-restraint to simulate the trapping episode, and investigated the acute (2 days after the restraint) and long-term (35 days after the restraint) impacts. Surprisingly, we found that the mice displayed depression-like behaviors, decreased glucose uptake in brain and reduced adult hippocampal neurogenesis 35 days after the restraint. Differential expression profiling based on microarrays suggested that genes and pathways related to depression and other mental disorders were differentially expressed in both PFC and hippocampus. Furthermore, the depression-like phenotypes induced by 24-hour-restraint could be reversed by fluoxetine, a type of antidepressant drug. These findings demonstrated that a single severe stressful event could produce long-term depressive-like phenotypes. Moreover, the 24-hour-restraint stress mice could also be used for further studies on mood disorders.

Male veterans with PTSD exhibit aberrant neural dynamics during working memory processing: an MEG study

BACKGROUND

Posttraumatic stress disorder (PTSD) is associated with executive functioning deficits, including disruptions in working memory. In this study, we examined the neural dynamics of working memory processing in veterans with PTSD and a matched healthy control sample using magnetoencephalography (MEG).

METHODS

Our sample of recent combat veterans with PTSD and demographically matched participants without PTSD completed a working memory task during a 306-sensor MEG recording. The MEG data were preprocessed and transformed into the time-frequency domain. Significant oscillatory brain responses were imaged using a beamforming approach to identify spatiotemporal dynamics.

RESULTS

Fifty-one men were included in our analyses: 27 combat veterans with PTSD and 24 controls. Across all participants, a dynamic wave of neural activity spread from posterior visual cortices to left frontotemporal regions during encoding, consistent with a verbal working memory task, and was sustained throughout maintenance. Differences related to PTSD emerged during early encoding, with patients exhibiting stronger α oscillatory responses than controls in the right inferior frontal gyrus (IFG). Differences spread to the right supramarginal and temporal cortices during later encoding where, along with the right IFG, they persisted throughout the maintenance period.

LIMITATIONS

This study focused on men with combat-related PTSD using a verbal working memory task. Future studies should evaluate women and the impact of various traumatic experiences using diverse tasks.

CONCLUSION

Posttraumatic stress disorder is associated with neurophysiological abnormalities during working memory encoding and maintenance. Veterans with PTSD engaged a bilateral network, including the inferior prefrontal cortices and supramarginal gyri. Right hemispheric neural activity likely reflects compensatory processing, as veterans with PTSD work to maintain accurate performance despite known cognitive deficits associated with the disorder.

Fluoxetine treatment prevents the inflammatory response in a mouse model of posttraumatic stress disorder

Despite intense research efforts the molecular mechanisms affecting stress-vulnerable brain regions in posttraumatic stress disorder (PTSD) remain elusive. In the current study we have applied global transcriptomic profiling to a PTSD mouse model induced by foot shock fear conditioning. We compared the transcriptomes of prelimbic cortex, anterior cingulate cortex (ACC), basolateral amygdala, central nucleus of amygdala, nucleus accumbens (NAc) and CA1 of the dorsal hippocampus between shocked and non-shocked (control) mice, with and without fluoxetine treatment by RNA sequencing. Differentially expressed (DE) genes were identified and clustered for in silico pathway analysis. Findings in relevant brain regions were further validated with immunohistochemistry. DE genes belonging to 11 clusters were identified including increased inflammatory response in ACC in shocked mice. In line with this finding, we noted higher microglial activation in ACC of shocked mice. Chronic fluoxetine treatment initiated in the aftermath of the trauma prevented inflammatory gene expression alterations in ACC and ameliorated PTSD-like symptoms, implying an important role of the immune response in PTSD pathobiology. Our results provide novel insights into molecular mechanisms affected in PTSD and suggest therapeutic applications with anti-inflammatory agents.

Chronic stress and brain plasticity: Mechanisms underlying adaptive and maladaptive changes and implications for stress-related CNS disorders

Stress responses entail neuroendocrine, autonomic, and behavioral changes to promote effective coping with real or perceived threats to one's safety. While these responses are critical for the survival of the individual, adverse effects of repeated exposure to stress are widely known to have deleterious effects on health. Thus, a considerable effort in the search for treatments to stress-related CNS disorders necessitates unraveling the brain mechanisms responsible for adaptation under acute conditions and their perturbations following chronic stress exposure. This paper is based upon a symposium from the 2014 International Behavioral Neuroscience Meeting, summarizing some recent advances in understanding the effects of stress on adaptive and maladaptive responses subserved by limbic forebrain networks. An important theme highlighted in this review is that the same networks mediating neuroendocrine, autonomic, and behavioral processes during adaptive coping also comprise targets of the effects of repeated stress exposure in the development of maladaptive states. Where possible, reference is made to the similarity of neurobiological substrates and effects observed following repeated exposure to stress in laboratory animals and the clinical features of stress-related disorders in humans.

EEG correlates of the severity of posttraumatic stress symptoms: A systematic review of the dimensional PTSD literature

BACKGROUND

Considering the Research Domain Criteria (RDoC) framework, it is crucial to investigate posttraumatic stress disorder (PTSD) as a spectrum that ranges from normal to pathological. This dimensional approach is especially important to aid early PTSD detection and to guide better treatment options. In recent years, electroencephalography (EEG) has been used to investigate PTSD; however, reviews regarding EEG data related to PTSD are lacking, especially considering the dimensional approach. This systematic review examined the literature regarding EEG alterations in trauma-exposed people with posttraumatic stress symptoms (PTSS) to identify putative EEG biomarkers of PTSS severity.

METHOD

A systematic review of EEG studies of trauma-exposed participants with PTSS that reported dimensional analyses (e.g., correlations or regressions) between PTSS and EEG measures was performed.

RESULTS

The literature search yielded 1178 references, of which 34 studies were eligible for inclusion. Despite variability among the reviewed studies, the PTSS severity was often associated with P2, P3-family event-related potentials (ERPs) and alpha rhythms.

LIMITATIONS

The search was limited to articles published in English; no information about non-published studies or studies reported in other languages was obtained. Another limitation was the heterogeneity of studies, which made meta-analysis challenging.

CONCLUSIONS

EEG provides promising candidates to act as biomarkers, although further studies are required to confirm the findings. Thus, EEG, in addition to being cheaper and easier to implement than other central techniques, has the potential to reveal biomarkers of PTSS severity.

Intracisternal Gtf2i Gene Therapy Ameliorates Deficits in Cognition and Synaptic Plasticity of a Mouse Model of Williams-Beuren Syndrome

Williams-Beuren syndrome (WBS) is a neurodevelopmental disorder caused by a heterozygous deletion of 26-28 genes at chromosome band 7q11.23. Haploinsufficiency at GTF2I has been shown to play a major role in the neurobehavioral phenotype. By characterizing the neuronal architecture in four animal models with intragenic, partial, and complete deletions of the WBS critical interval (ΔGtf2i(+/-), ΔGtf2i( -/-), PD, and CD), we clarify the involvement of Gtf2i in neurocognitive features. All mutant mice showed hypersociability, impaired motor learning and coordination, and altered anxiety-like behavior. Dendritic length was decreased in the CA1 of ΔGtf2i(+/-), ΔGtf2i ( -/-), and CD mice. Spine density was reduced, and spines were shorter in ΔGtf2i ( -/-), PD, and CD mice. Overexpression of Pik3r1 and downregulation of Bdnf were observed in ΔGtf2i(+/-), PD, and CD mice. Intracisternal Gtf2i-gene therapy in CD mice using adeno-associated virus resulted in increased mGtf2i expression and normalization of Bdnf levels, along with beneficial effects in motor coordination, sociability, and anxiety, despite no significant changes in neuronal architecture. Our findings further indicate that Gtf2i haploinsufficiency plays an important role in the neurodevelopmental and cognitive abnormalities of WBS and that it is possible to rescue part of this neurocognitive phenotype by restoring Gtf2i expression levels in specific brain areas.

Clinical effectiveness of interventions for treatment-resistant anxiety in older people: a systematic review

BACKGROUND

Anxiety and related disorders include generalised anxiety disorder, obsessive-compulsive disorder, panic disorder, post-traumatic stress disorder and phobic disorders (intense fear of an object or situation). These disorders share the psychological and physical symptoms of anxiety, but each disorder has its own set of characteristic symptoms. Anxiety disorders can be difficult to recognise, particularly in older people (those aged over 65 years). Older people tend to be more reluctant to discuss mental health issues and there is the perception that older people are generally more worried than younger adults. It is estimated that between 3 and 14 out of every 100 older people have an anxiety disorder. Despite treatment, some people will continue to have symptoms of anxiety. People are generally considered to be 'resistant' or 'refractory' to treatment if they have an inadequate response or do not respond to their first treatment. Older adults with an anxiety disorder find it difficult to manage their day-to-day lives and are at an increased risk of comorbid depression, falls, physical and functional disability, and loneliness.

OBJECTIVE

To evaluate the effectiveness of pharmacological, psychological and alternative therapies in older adults with an anxiety disorder who have not responded, or have responded inadequately, to treatment.

DATA SOURCES

Electronic databases (MEDLINE, MEDLINE In-Process and Other Non-Indexed citations, EMBASE, The Cochrane Library databases, PsycINFO and Web of Science) were searched from inception to September 2013. Bibliographies of relevant systematic reviews were hand-searched to identify additional potentially relevant studies. ClinicalTrials.gov was searched for ongoing and planned studies.

REVIEW METHODS

A systematic review of the clinical effectiveness of treatments for treatment-resistant anxiety in older adults was carried out.

RESULTS

No randomised controlled trial or prospective comparative observational study was identified meeting the prespecified inclusion criteria. Therefore, it was not possible to draw any conclusions on clinical effectiveness.

LIMITATIONS

As no study was identified in older adults, there is uncertainty as to which treatments are clinically effective for older adults with an anxiety disorder who have not responded to prior treatment. The comprehensive methods implemented to carry out this review are a key strength of the research presented. However, this review highlights the extreme lack of research in this area, identifying no comparative studies, which is a marked limitation.

CONCLUSIONS

Specific studies evaluating interventions in older adults with an anxiety disorder who have not responded to first-line treatment are needed to address the lack of evidence. The lack of evidence in this area means that older adults are perhaps receiving inappropriate treatment or are not receiving a particular treatment because there is limited evidence to support its use. At this time there is scope to develop guidance on service provision and, as a consequence, to advance the standard of care received by older adults with a treatment-resistant anxiety disorder in primary and secondary care. Evaluation of the relative clinical effectiveness and acceptability of pharmacological and psychological treatment in older adults with an anxiety disorder that has not responded to first-line treatment is key future research to inform decision-making of clinicians and patients. An important consideration would be the enrolment of older adults who would be representative of older adults in general, i.e. those with multiple comorbid physical and mental disorders who might require polypharmacy.

STUDY REGISTRATION

The protocol for the systematic review is registered on PROSPERO (registration number CRD42013005612).

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Repetitive transcranial magnetic stimulation for clinical applications in neurological and psychiatric disorders: an overview

Neurological and psychiatric disorders are characterized by several disabling symptoms for which effective, mechanism-based treatments remain elusive. Consequently, more advanced non-invasive therapeutic methods are required. A method that may modulate brain activity and be viable for use in clinical practice is repetitive transcranial magnetic stimulation (rTMS). It is a non-invasive procedure whereby a pulsed magnetic field stimulates electrical activity in the brain. Here, we focus on the basic foundation of rTMS, the main stimulation parametters, the factors that influence individual responses to rTMS and the experimental advances of rTMS that may become a viable clinical application to treat neurological and psychiatric disorders. The findings showed that rTMS can improve some symptoms associated with these conditions and might be useful for promoting cortical plasticity in patients with neurological and psychiatric disorders. However, these changes are transient and it is premature to propose these applications as realistic therapeutic options, even though the rTMS technique has been evidenced as a potential modulator of sensorimotor integration and neuroplasticity. Functional imaging of the region of interest could highlight the capacity of rTMS to bring about plastic changes of the cortical circuitry and hint at future novel clinical interventions. Thus, we recommend that further studies clearly determine the role of rTMS in the treatment of these conditions. Finally, we must remember that however exciting the neurobiological mechanisms might be, the clinical usefulness of rTMS will be determined by its ability to provide patients with neurological and psychiatric disorders with safe, long-lasting and substantial improvements in quality of life.

Changes in integrin αv, vinculin and connexin43 in the medial prefrontal cortex in rats under single-prolonged stress

Post‑traumatic stress disorder (PTSD) is a stress‑accociated mental disorder that occurs as a result of exposure to a traumatic event, with characteristic symptoms, including intrusive memories, hyperarousal and avoidance. The medial prefrontal cortex (mPFC) is known to be significantly involved in emotional adjustment, particularly introspection, inhibition of the amygdala and emotional memory. Previous structural neuroimaging studies have revealed that the mPFC of PTSD patients was significantly smaller when compared with that of controls and their emotional adjustment function was weakened. However, the mechanisms that cause such atrophy remain to be elucidated. The aim of the present study was to elucidate the possible mechanisms involved in apoptosis induced by single‑prolonged stress (SPS) in the mPFC of PTSD rats. SPS is an animal model reflective of PTSD. Of the proposed animal models of PTSD, SPS is one that has been shown to be reliably reproducible in patients with PTSD. Wistar rats were sacrificed at 1, 4, 7 and 14 days after exposure to SPS. Apoptotic cells were assessed using electron microscopy and the TUNEL method. Expression of integrin αv, vinculin and connexin43 were detected using immunohistochemistry, western blotting and reverse transcription polymerase chain reaction. The present results demonstrated that apoptotic cells significantly increased in the mPFC of SPS rats, accompanied with changes in expression of integrin αv, vinculin and connexin43. The present results indicated that SPS‑induced apoptosis in the mPFC of PTSD rats and the mitochondrial pathway were involved in the process of SPS‑induced apoptosis.

Hippocampal--prefrontal BDNF and memory for fear extinction

Infusing brain-derived neurotrophic factor (BDNF) into the infralimbic (IL) prefrontal cortex is capable of inducing extinction. Little is known, however, about the circuits mediating BDNF effects on extinction or the extent to which extinction requires BDNF in IL. Using local pharmacological infusion of BDNF protein, or an antibody against BDNF, we found that BDNF in the IL, but not prelimbic (PL) prefrontal cortex, is both necessary and sufficient for fear extinction. Furthermore, we report that BDNF in IL can induce extinction of older fear memories (14 days) as well as recent fear memories (1 day). Using immunocytochemistry, we show that BDNF is increased in the ventral hippocampus (vHPC), but not IL or PL, following extinction training. Finally, we observed that infusing BDNF into the vHPC increased the firing rate of IL, but not PL neurons in fear conditioned rats. These findings indicate that an extinction-induced increase in BDNF within the vHPC enhances excitability in IL targets, thereby supporting extinction memories.

Biofeedback-based training for stress management in daily hassles: an intervention study

BACKGROUND

The day-to-day causes of stress are called daily hassles. Daily hassles are correlated with ill health. Biofeedback (BF) is one of the tools used for acquiring stress-coping skills. However, the anatomical correlates of the effects of BF with long training periods remain unclear. In this study, we aimed to investigate this.

METHODS

PARTICIPANTS WERE ASSIGNED RANDOMLY TO TWO GROUPS: the intervention group and the control group. Participants in the intervention group performed a biofeedback training (BFT) task (a combination task for heart rate and cerebral blood flow control) every day, for about 5 min once a day. The study outcomes included MRI, psychological tests (e.g., Positive and Negative Affect Schedule, Center for Epidemiologic Studies Depression Scale, and Brief Job Stress Questionnaire), and a stress marker (salivary cortisol levels) before (day 0) and after (day 28) the intervention.

RESULTS

We observed significant improvements in the psychological test scores and salivary cortisol levels in the intervention group compared to the control group. Furthermore, voxel-based morphometric analysis revealed that compared to the control group, the intervention group had significantly increased regional gray matter (GM) volume in the right lateral orbitofrontal cortex, which is an anatomical cluster that includes mainly the left hippocampus, and the left subgenual anterior cingulate cortex. The GM regions are associated with the stress response, and, in general, these regions seem to be the most sensitive to the detrimental effects of stress.

CONCLUSIONS

Our findings suggest that our BFT is effective against the GM structures vulnerable to stress.

A practical measure of workplace resilience: developing the resilience at work scale

OBJECTIVE

To develop an effective measure of resilience at work for use in individual work-related performance and emotional distress contexts.

METHODS

Two separate cross-sectional studies investigated: (1) exploratory factor analysis of 45 items putatively underpinning workplace resilience among 397 participants and (2) confirmatory factor analysis of resilience measure derived from Study 1 demonstrating a credible model of interaction, with performance outcome variables among 194 participants.

RESULTS

A 20-item scale explaining 67% of variance, measuring seven aspects of workplace resilience, which are teachable and capable of conscious development, was achieved. A credible model of relationships with work engagement, sleep, stress recovery, and physical health was demonstrated in the expected directions.

CONCLUSION

The new scale shows considerable promise as a reliable instrument for use in the area of employee support and development.

Prefrontal responses to digit span memory phases in patients with post-traumatic stress disorder (PTSD): a functional near infrared spectroscopy study

Neuroimaging studies of post-traumatic stress disorder (PTSD)-related memory impairments have consistently implicated abnormal activities in the frontal and parietal lobes. However, most studies have used block designs and could not dissociate the multiple phases of working memory. In this study, the involvement of the prefrontal cortex in working memory phases was assessed among veterans with PTSD and age-/gender-matched healthy controls. Multichannel functional near infrared spectroscopy (fNIRS) was utilized to measure prefrontal cortex hemodynamic activations during memory of neutral (i.e., not trauma-related) forward and backward digit span tasks. An event-related experimental design was utilized to dissociate the different phases (i.e., encoding, maintenance and retrieval) of working memory. The healthy controls showed robust hemodynamic activations during the encoding and retrieval processes. In contrast, the veterans with PTSD were found to have activations during the encoding process, but followed by distinct deactivations during the retrieval process. The PTSD participants, but not the controls, appeared to suppress prefrontal activity during memory retrieval. This deactivation was more pronounced in the right dorsolateral prefrontal cortex during the retrieval phase. These deactivations in PTSD patients might implicate an active inhibition of dorsolateral prefrontal neural activity during retrieval of working memory.

Hypnotizability, hypnosis and prepulse inhibition of the startle reflex in healthy women: an ERP analysis

A working model of the neurophysiology of hypnosis suggests that highly hypnotizable individuals (HHs) have more effective frontal attentional systems implementing control, monitoring performance, and inhibiting unwanted stimuli from conscious awareness, than low hypnotizable individuals (LHs). Recent studies, using prepulse inhibition (PPI) of the auditory startle reflex (ASR), suggest that HHs, in the waking condition, may show reduced sensory gating although they may selectively attend and disattend different stimuli. Using a within subject design and a strict subject selection procedure, in waking and hypnosis conditions we tested whether HHs compared to LHs showed a significantly lower inhibition of the ASR and startle-related brain activity in both time and intracerebral source localization domains. HHs, as compared to LH participants, exhibited (a) longer latency of the eyeblink startle reflex, (b) reduced N100 responses to startle stimuli, and (c) higher PPI of eyeblink startle and of the P200 and P300 waves. Hypnosis yielded smaller N100 waves to startle stimuli and greater PPI of this component than in the waking condition. sLORETA analysis revealed that, for the N100 (107 msec) elicited during startle trials, HHs had a smaller activation in the left parietal lobe (BA2/40) than LHs. Auditory pulses of pulse-with prepulse trials in HHs yielded less activity of the P300 (280 msec) wave than LHs, in the cingulate and posterior cingulate gyrus (BA23/31). The present results, on the whole, are in the opposite direction to PPI findings on hypnotizability previously reported in the literature. These results provide support to the neuropsychophysiological model that HHs have more effective sensory integration and gating (or filtering) of irrelevant stimuli than LHs.

Evening-type military veterans report worse lifetime posttraumatic stress symptoms and greater brainstem activity across wakefulness and REM sleep

Evening chronotypes exhibit increased rates of affective dyregulation and sleep disturbances (e.g., insomnia and nightmares). Such symptoms are common to military veterans with posttraumatic stress disorder (PTSD); however, the influence of chronotype on this population remains unknown. We examined behavioral, psychological, and neural correlates of chronotype in 36 combat-exposed military veterans with varying degrees of posttraumatic stress symptomatology. We employed FDG-PET to assess neural activity across wakefulness and rapid eye movement (REM) sleep. We used polysomnography and diaries to monitor sleep, and a self-report survey to measure chronotype. Eveningness was associated with greater lifetime PTSD symptoms, more disturbed sleep, and more frequent and intense nightmares. Eveningness was also associated with greater brain activity in posterior cingulate/precuneus and brainstem regions across wakefulness and REM sleep, overlapping with regions related to arousal and REM sleep generation. Chronotype may be an important correlate of neural activity in REM sleep-generating and/or arousal regulatory regions among combat-exposed veterans with PTSD symptoms. Further investigations of the role of chronotype in PTSD are warranted.

Impact of early vs. late childhood early life stress on brain morphometrics

Previous studies of early life trauma suggest that in addition to its emotional impact, exposure to early life stress (ELS) is associated with alterations in brain structure. However, little attention has been devoted to the relationship between emotional processing and brain integrity as a function of age of ELS onset. In the present study we examined whether ELS onset in older ages of youth rather than younger ages is associated with smaller limbic and basal ganglia volumes as measured by magnetic resonance imaging (MRI). We hypothesized that later age of manifestation during youth is associated with smaller volumetric morphology in limbic and basal ganglia volumes in adulthood. A total of 173 individuals were divided into three groups based on the age of self-reported ELS. The three groups included individuals only experiencing early childhood ELS (1 month-7 years, n = 38), those only experiencing later childhood ELS (8 years -17 years, n = 59), and those who have not experienced ELS (n = 76). Anterior cingulate cortex (ACC), hippocampus, amygdala, insula and caudate volumes were measured using a T1-weighted MRI. Analyses confirmed that later childhood ELS was associated with volumetric reductions in the ACC and insula volumes, while ELS experienced between the ages of 1 month and 7 years was not associated with lower brain volumes in these regions. The results may reflect the influence of more fully developed emotional processing of ELS on the developing brain and reinforce a body of research implicating both the ACC and insula in neuropsychiatric disorders and emotional regulation.

Epigenetic mechanisms in learned fear: implications for PTSD

One of the most exciting discoveries in the learning and memory field in the past two decades is the observation that active regulation of gene expression is necessary for experience to trigger lasting functional and behavioral change, in a wide variety of species, including humans. Thus, as opposed to the traditional view of 'nature' (genes) being separate from 'nurture' (environment and experience), it is now clear that experience actively drives alterations in central nervous system (CNS) gene expression in an ongoing fashion, and that the resulting transcriptional changes are necessary for experience to trigger altered long-term behavior. In parallel over the past decade, epigenetic mechanisms, including regulation of chromatin structure and DNA methylation, have been shown to be potent regulators of gene transcription in the CNS. In this review, we describe data supporting the hypothesis that epigenetic molecular mechanisms, especially DNA methylation and demethylation, drive long-term behavioral change through active regulation of gene transcription in the CNS. Specifically, we propose that epigenetic molecular mechanisms underlie the formation and stabilization of context- and cue-triggered fear conditioning based in the hippocampus and amygdala, a conclusion reached in a wide variety of studies using laboratory animals. Given the relevance of cued and contextual fear conditioning to post-traumatic stress, by extension we propose that these mechanisms may contribute to post-traumatic stress disorder (PTSD) in humans. Moreover, we speculate that epigenetically based pharmacotherapy may provide a new avenue of drug treatment for PTSD-related cognitive and behavioral function.

Sex differences in fear conditioning in posttraumatic stress disorder

BACKGROUND

Women are twice as likely as men to develop Posttraumatic Stress Disorder (PTSD). Abnormal acquisition of conditioned fear has been suggested as a mechanism for the development of PTSD. While some studies of healthy humans suggest that women are either no different or express less conditioned fear responses during conditioning relative to men, differences in the acquisition of conditioned fear between men and women diagnosed with PTSD has not been examined.

METHODS

Thirty-one participants (18 men; 13 women) with full or subsyndromal PTSD completed a fear conditioning task. Participants were shown computer-generated colored circles that were paired (CS+) or unpaired (CS-) with an aversive electrical stimulus and skin conductance levels were assessed throughout the task.

RESULTS

Repeated measures ANOVA indicated a significant sex by stimulus interaction during acquisition. Women had greater differential conditioned skin conductance responses (CS + trials compared to CS- trials) than did men, suggesting greater acquisition of conditioned fear in women with PTSD.

CONCLUSIONS

In contrast to studies of healthy individuals, we found enhanced acquisition of conditioned fear in women with PTSD. Greater fear conditioning in women may either be a pre-existing vulnerability trait or an acquired phenomenon that emerges in a sex-dependent manner after the development of PTSD. Characterizing the underlying mechanisms of these differences is needed to clarify sex-related differences in the pathophysiology of PTSD.

Individual variations in maternal care early in life correlate with later life decision-making and c-fos expression in prefrontal subregions of rats

Early life adversity affects hypothalamus-pituitary-adrenal axis activity, alters cognitive functioning and in humans is thought to increase the vulnerability to psychopathology--e.g. depression, anxiety and schizophrenia--later in life. Here we investigated whether subtle natural variations among individual rat pups in the amount of maternal care received, i.e. differences in the amount of licking and grooming (LG), correlate with anxiety and prefrontal cortex-dependent behavior in young adulthood. Therefore, we examined the correlation between LG received during the first postnatal week and later behavior in the elevated plus maze and in decision-making processes using a rodent version of the Iowa Gambling Task (rIGT). In our cohort of male and female animals a high degree of LG correlated with less anxiety in the elevated plus maze and more advantageous choices during the last 10 trials of the rIGT. In tissue collected 2 hrs after completion of the task, the correlation between LG and c-fos expression (a marker of neuronal activity) was established in structures important for IGT performance. Negative correlations existed between rIGT performance and c-fos expression in the lateral orbitofrontal cortex, prelimbic cortex, infralimbic cortex and insular cortex. The insular cortex correlations between c-fos expression and decision-making performance depended on LG background; this was also true for the lateral orbitofrontal cortex in female rats. Dendritic complexity of insular or infralimbic pyramidal neurons did not or weakly correlate with LG background. We conclude that natural variations in maternal care received by pups may significantly contribute to later-life decision-making and activity of underlying brain structures.

A meta-analysis of functional neuroimaging studies of self- and other judgments reveals a spatial gradient for mentalizing in medial prefrontal cortex

The distinction between processes used to perceive and understand the self and others has received considerable attention in psychology and neuroscience. Brain findings highlight a role for various regions, in particular the medial PFC (mPFC), in supporting judgments about both the self and others. We performed a meta-analysis of 107 neuroimaging studies of self- and other-related judgments using multilevel kernel density analysis [Kober, H., & Wager, T. D. Meta-analyses of neuroimaging data. Wiley Interdisciplinary Reviews, 1, 293-300, 2010]. We sought to determine what brain regions are reliably involved in each judgment type and, in particular, what the spatial and functional organization of mPFC is with respect to them. Relative to nonmentalizing judgments, both self- and other judgments were associated with activity in mPFC, ranging from ventral to dorsal extents, as well as common activation of the left TPJ and posterior cingulate. A direct comparison between self- and other judgments revealed that ventral mPFC as well as left ventrolateral PFC and left insula were more frequently activated by self-related judgments, whereas dorsal mPFC, in addition to bilateral TPJ and cuneus, was more frequently activated by other-related judgments. Logistic regression analyses revealed that ventral and dorsal mPFC lay at opposite ends of a functional gradient: The z coordinates reported in individual studies predicted whether the study involved self- or other-related judgments, which were associated with increasingly ventral or dorsal portions of mPFC, respectively. These results argue for a distributed rather than localizationist account of mPFC organization and support an emerging view on the functional heterogeneity of mPFC.

Source imaging of P300 auditory evoked potentials and clinical correlations in patients with posttraumatic stress disorder

OBJECTIVE

Posttraumatic stress disorder (PTSD) is associated with abnormal information processing. The P300 component of event-related potentials (ERPs) is known to be a useful marker of information processing. The purposes of this study were to determine the P300 current source density in PTSD patients, and its relationship with symptom severity.

METHODS

ERPs were recorded in 30 PTSD patients and 33 healthy controls while participants were performing the auditory oddball task. We compared P300 current source density data--obtained by standardized low-resolution brain electromagnetic tomography (sLORETA)--between the two groups. The correlation between P300 current source density and clinical symptoms (as evaluated using the Korean version of the Structured Interview for PTSD--K-SIPS and Davidson Trauma Scale--K-DTS) was conducted.

RESULTS

In PTSD patients, the current source density of P300 is significantly reduced in the inferior frontal gyrus, precentral gyrus, insula, and anterior cingulate compared to healthy controls. Total K-DTS scores were correlated with the P300 current source density in the posterior cingulate gyrus. The K-SIP B items (re-experiencing) and K-SIB D items (increased arousal) were positively correlated with P300 current source densities in several brain regions located in the frontal, parietal, and temporal lobe (p<0.05). Conversely, the K-SIP C items (avoidance and numbing) were negatively correlated with P300 current source densities in the superior and middle frontal gyri in the frontal lobes (p<0.05).

CONCLUSION

The P300 current source densities reflected the pathophysiology of PTSD patients. PTSD symptoms were related to different neural activities, depending on their symptom characteristics.

The effect of comorbid anxiety disorder on neuropsychological function in bipolar II disorder

OBJECTIVES

Bipolar disorder (BP) is often comorbid with anxiety disorder (ANX), especially in bipolar II disorder (BP-II). BP patients with comorbid ANX often manifest intensified symptoms and harmful dysfunctions. However, most studies have focused on bipolar I disorder (BP-I); few have investigated the effect of comorbid ANX on the neuropsychological function of BP-II patients. We examined neuropsychological functions in BP-II patients with and without comorbid ANX.

METHODS

Fifty-nine participants were recruited: 20 patients with interepisode (symptom-free) BP-II without comorbid ANX, 20 with interepisode BP-II with comorbid ANX, and 19 healthy controls. All participants were screened using the Chinese version of the Modified Schedule of Affective Disorder and Schizophrenia-Lifetime (SADS-L). Individuals comorbid with major or minor mental illness other than BP-II were excluded. Comparisons were made between the three groups using neuropsychological tests to assess memory, attention, psychomotor speed, and frontal executive function.

RESULTS

BP-II patients with comorbid ANX showed poorer neuropsychological functions than those in the BP-II-only and control groups. Additionally, BP-II-only patients and controls showed equal cognitive performance.

CONCLUSIONS

Because BP-II patients with comorbid ANX had the lowest scores in the majority of neuropsychological functional tests, we conclude that they have greater cognitive impairments than do BP-II patients without comorbid ANX. Neuropsychological dysfunctions seemed more strongly associated with ANX than with BP-II in interepisode periods. Identifying and managing ANX comorbidity is critical when treating BP-II patients.

Cortisol awakening response prospectively predicts peritraumatic and acute stress reactions in police officers

BACKGROUND

The hypothalamic-pituitary-adrenal axis is a major stress response system hypothesized to be involved in the pathogenesis of posttraumatic stress disorder (PTSD). However, few studies have prospectively examined the relationships among pre-exposure hypothalamic-pituitary-adrenal activity, acute stress reactions and PTSD.

METHODS

Two hundred ninety-six police recruits were assessed during academy training before critical incident exposure and provided salivary cortisol at first awakening and after 30 minutes. A measure of cortisol awakening response (CAR) was computed as the change in cortisol level from the first to the second collection. At 12, 24, and 36 months following the start of active police service, officers were assessed for peritraumatic distress, peritraumatic dissociation, acute stress disorder (ASD) symptoms, and PTSD symptoms to their self-identified worst duty-related critical incident. Mixed models for repeated measures were used to analyze the effects of CAR on the outcome variables pooled across the three follow-up assessments.

RESULTS

After controlling for time of awakening, first awakening cortisol levels, and cumulative critical incident stress exposure, CAR during academy training was associated with greater peritraumatic dissociation, β = .14, z = 3.49, p < .0001, and greater ASD symptoms during police service assessed at 12, 24, and 36 months, β = .09, Z = 2.03, p < .05, but not with peritraumatic distress, β = .03, z = .81, p = .42, or PTSD symptoms, β = -.004, z = -.09, p = .93.

CONCLUSIONS

These findings suggest that greater cortisol response to awakening is a pre-exposure risk factor for peritraumatic dissociation and ASD symptoms during police service.

Long-lasting effects of maternal separation on an animal model of post-traumatic stress disorder: effects on memory and hippocampal oxidative stress

Adverse early life events, such as periodic maternal separation, may alter the normal pattern of brain development and subsequently the vulnerability to a variety of mental disorders in adulthood. Patients with a history of early adversities show higher frequency of post-traumatic stress disorder (PTSD). This study was undertaken to verify if repeated long-term separation of pups from dams would affect memory and oxidative stress parameters after exposure to an animal model of PTSD. Nests of Wistar rats were divided into intact and subjected to maternal separation (incubator at 32°C, 3 h/day) during post-natal days 1-10. When adults, the animals were subdivided into exposed or not to a PTSD model consisting of exposure to inescapable footshock, followed by situational reminders. One month after exposure to the shock, the animals were exposed to a memory task (Morris water maze) and another month later animals were sacrificed and DNA breaks and antioxidant enzymes activities were measured in the hippocampus. Rats exposed to shock or maternal separation plus shock showed long-lasting effects on spatial memory, spending more time in the opposite quadrant of the water maze. This effect was higher in animals subjected to both maternal separation and shock. Both shock and maternal separation induced a higher score of DNA breaks in the hippocampus. No differences were observed on antioxidant enzymes activities. In conclusion, periodic maternal separation may increase the susceptibility to the effects of a stressor applied in adulthood on performance in the water maze. Increased DNA breaks in hippocampus was induced by both, maternal separation and exposure to shock.

Stress modulation of cognitive and affective processes

This review summarizes the major discussion points of a symposium on stress modulation of cognitive and affective processes, which was held during the 2010 workshop on the neurobiology of stress (Boulder, CO, USA). The four discussants addressed a number of specific cognitive and affective factors that are modulated by exposure to acute or repeated stress. Dr David Morilak discussed the effects of various repeated stress situations on cognitive flexibility, as assessed with a rodent model of attentional set-shifting task, and how performance on slightly different aspects of this test is modulated by different prefrontal regions through monoaminergic neurotransmission. Dr Serge Campeau summarized the findings of several studies exploring a number of factors and brain regions that regulate habituation of various autonomic and neuroendocrine responses to repeated audiogenic stress exposures. Dr Kerry Ressler discussed a body of work exploring the modulation and extinction of fear memories in rodents and humans, especially focusing on the role of key neurotransmitter systems including excitatory amino acids and brain-derived neurotrophic factor. Dr Israel Liberzon presented recent results on human decision-making processes in response to exogenous glucocorticoid hormone administration. Overall, these discussions are casting a wider framework on the cognitive/affective processes that are distinctly regulated by the experience of stress and some of the brain regions and neurotransmitter systems associated with these effects.

Changes in brain anatomy during the course of posttraumatic stress disorder

The goal of this study was to determine whether posttraumatic stress disorder (PTSD) was associated with an increase in time-related decline in macrostructural brain volume and whether these changes were associated with accelerated cognitive decline. To quantify brain structure, three-dimensional T1-weighted MRI scans were performed at baseline and again after a minimum of 24months in 25 patients with PTSD (PTSD+) and 22 controls (PTSD-). Longitudinal changes in brain volume were measured using deformation morphometry. For the group as a whole, PTSD+ patients did not show significant ongoing brain atrophy compared to PTSD-. PTSD+ patients were then subgrouped into those with decreasing or increasing symptoms. We found little evidence for brain markers of accelerated atrophy in PTSD+ veterans whose symptoms improved over time, with only a small left parietal region showing greater ongoing tissue loss than PTSD-. PTSD patients whose symptoms increased over time showed accelerated atrophy throughout the brain, particularly brainstem and frontal and temporal lobes. Lastly, for the sample as a whole, greater rates of brain atrophy were associated with greater rates of decline in verbal memory and delayed facial recognition.

Chronic stress induces changes in the structure of interneurons and in the expression of molecules related to neuronal structural plasticity and inhibitory neurotransmission in the amygdala of adult mice

Chronic stress in experimental animals, one of the most accepted models of chronic anxiety and depression, induces structural remodeling of principal neurons in the amygdala and increases its excitation by reducing inhibitory tone. These changes may be mediated by the polysialylated form of the neural cell adhesion molecule (PSA-NCAM), a molecule related to neuronal structural plasticity and expressed by interneurons in the adult CNS, which is downregulated in the amygdala after chronic stress. We have analyzed the amygdala of adult mice after 21 days of restraint stress, studying with qRT-PCR the expression of genes related to general and inhibitory neurotransmission, and of PSA synthesizing enzymes. The expression of GAD67, synaptophysin and PSA-NCAM was also studied in specific amygdaloid nuclei using immunohistochemistry. We also analyzed dendritic arborization and spine density, and cell activity, monitoring c-Fos expression, in amygdaloid interneurons. At the mRNA level, the expression of GAD67 and of St8SiaII was significantly reduced. At the protein level there was an overall reduction in the expression of GAD67, synaptophysin and PSA-NCAM, but significant changes were only detected in specific amygdaloid regions. Chronic stress did not affect dendritic spine density, but reduced dendritic arborization in interneurons of the lateral and basolateral amygdala. These results indicate that chronic stress modulates inhibitory neurotransmission in the amygdala by regulating the expression of molecules involved in this process and by promoting the structural remodeling of interneurons. The addition of PSA to NCAM by St8SiaII may be involved in these changes.

Is rTMS an effective therapeutic strategy that can be used to treat anxiety disorders?

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive procedure whereby a pulsed magnetic field stimulates electrical activity in the brain. Anxiety disorders are the most common of all mental health problems for which effective, mechanism-based treatments remain elusive. Consequently, more advanced non-invasive therapeutic methods are required. A possible method to modulate brain activity and potentially viable for use in clinical practice is rTMS. Here, we focus on the main findings of rTMS from animal models of anxiety and the experimental advances of rTMS that may become a viable clinical application to treat anxiety disorders, one of the most common causes of disability in the workplace in the world. Key advances in combining rTMS with neuroimaging technology may aid such future developments. This article is part of a Special Issue entitled 'Anxiety and Depression'.

Subcortical volumes in long-term abstinent alcoholics: associations with psychiatric comorbidity

BACKGROUND

Research in chronic alcoholics on memory, decision-making, learning, stress, and reward circuitry has increasingly highlighted the importance of subcortical brain structures. In addition, epidemiological studies have established the pervasiveness of co-occurring psychiatric diagnoses in alcoholism. Subcortical structures have been implicated in externalizing pathology, including alcohol dependence, and in dysregulated stress and reward circuitry in anxiety and mood disorders and alcohol dependence. Most studies have focused on active or recently detoxified alcoholics, while subcortical structures in long-term abstinent alcoholics (LTAA) have remained relatively uninvestigated.

METHODS

Structural MRI was used to compare volumes of 8 subcortical structures (lateral ventricles, thalamus, caudate, putamen, pallidum, hippocampus, amygdala, and nucleus accumbens) in 24 female and 28 male LTAA (mean abstinence=6.3 years, mean age= 46.6 years) and 23 female and 25 male nonalcoholic controls (NAC) (mean age=45.6 years) to explore relations between subcortical brain volumes and alcohol use measures in LTAA and relations between subcortical volumes and psychiatric diagnoses and symptom counts in LTAA and NAC.

RESULTS

We found minimal differences between LTAA and NAC in subcortical volumes. However, in LTAA, but not NAC, volumes of targeted subcortical structures were smaller in individuals with versus without comorbid lifetime or current psychiatric diagnoses, independent of lifetime alcohol consumption.

CONCLUSIONS

Our finding of minimal differences in subcortical volumes between LTAA and NAC is consistent with LTAA never having had volume deficits in these regions. However, given that imaging studies have frequently reported smaller subcortical volumes in active and recently detoxified alcoholics compared to controls, our results are also consistent with the recovery of subcortical volumes with sustained abstinence. The finding of persistent smaller subcortical volumes in LTAA, but not NAC, with comorbid psychiatric diagnoses, suggests that the smaller volumes are a result of the combined effects of chronic alcohol dependence and psychiatric morbidity and suggests that a comorbid psychiatric disorder (even if not current) interferes with the recovery of subcortical volumes.

Impact of childhood trauma, alexithymia, dissociation, and emotion suppression on emotional Stroop task

OBJECTIVE

Attentional bias to emotion- and illness-related information plays a prominent role in many mental disorders, particularly major depressive disorder and anxiety disorders. Using the emotional Stroop task we investigated which variables beyond aspects of patients' psychopathology might influence reaction times and interference in the Stroop test.

METHODS

We investigated 82 psychosomatic inpatients and 39 healthy controls. Diagnosis of depressive disorders, anxiety disorders, and somatoform disorders were established using the Structured Clinical Interview for DSM-IV. Severity of depression, anxiety, somatic symptoms, as well as experiences of childhood trauma, alexithymia, dissociation and emotion suppression were assessed via questionnaires. The emotional Stroop test was performed by using neutral and negative words, words related to depression, anxiety and somatization, respectively, and individually chosen words, which were related to the main problems of the participants.

RESULTS

In multivariate regression analyses, reaction times were best predicted by self-reported experiences of childhood trauma. Interference, by contrast, was predicted by emotion suppression, but only for negative words, anxiety-related words and individually relevant words. Against our hypothesis, measurements of psychopathology were not associated with Stroop performance.

CONCLUSIONS

The present study provides further support for the idea that the experience of childhood trauma influences adult neuropsychological performance. Furthermore, the findings suggest that the ability to suppress emotions may be an important predictor of attentional bias.

Functional neural correlates of mindfulness meditations in comparison with psychotherapy, pharmacotherapy and placebo effect. Is there a link?

Chiesa A, Brambilla P, Serretti A. Functional neural correlates of mindfulness meditations in comparison with psychotherapy, pharmacotherapy and placebo effect. Is there a link?

OBJECTIVE

Mindfulness meditations (MM) are a group of meditation practices which are increasingly receiving attention. The aim of the present work is to review current findings about the neural correlates of MM and compare such findings with other specific and non-specific treatments.

METHODS

A literature search was undertaken using MEDLINE, ISI web of knowledge, the Cochrane database and references of retrieved articles. Studies which focused on the functional neural correlates of MM, psychotherapy, pharmacotherapy and placebo published up to August 2009 were screened in order to be considered for the inclusion.

RESULTS

Main findings suggest that long-term MM practice allows a more flexible emotional regulation by engaging frontal cortical structures to dampen automatic amygdala activation. A large overlap exists between cerebral areas activated during MM, psychotherapy, pharmacotherapy and those activated by placebo. However, while MM, psychotherapy and placebo seem to act through a top-down regulation, antidepressants seem to act through a bottom-up process.

CONCLUSION

MM seem to target specific brain areas related to emotions and emotional regulation. Similar mechanisms have been observed also in other interventions, particularly psychotherapy.

Gray matter density in limbic and paralimbic cortices is associated with trauma load and EMDR outcome in PTSD patients

There is converging evidence of gray matter (GM) structural alterations in different limbic structures in Post-Traumatic Stress Disorder (PTSD) patients. The aim of this study was to evaluate GM density in PTSD in relation to trauma load, and to assess the GM differences between responders (R) and non-responders (NR) to EMDR therapy. Magnetic Resonance Imaging (MRI) scans of 21 subjects exposed to occupational trauma, who developed PTSD (S), and of 22 who did not (NS), were compared by means of an optimized Voxel-Based Morphometry (VBM) analysis as implemented in SPM. Within S, further comparisons were made between 10 R and 5 NR. A regression analysis between GM density and the Traumatic Antecedents Questionnaire (TAQ) was also performed on all 43 subjects. Results showed a significantly lower GM density in S as compared to NS in the left posterior cingulate and the left posterior parahippocampal gyrus. Moreover, NR showed a significantly lower GM density as compared to R in bilateral posterior cingulate, as well as anterior insula, anterior parahippocampal gyrus and amygdala in the right hemisphere. Regression analysis showed that GM density negatively correlated with trauma load in bilateral posterior cingulate, left anterior insula, and right anterior parahippocampal gyrus. In conclusion, a GM lower density in limbic and paralimbic cortices were found to be associated with PTSD diagnosis, trauma load, and EMDR treatment outcome, suggesting a view of PTSD characterized by memory and dissociative disturbances.

Re-examination of the Controversial Coexistence of Traumatic Brain Injury and Posttraumatic Stress Disorder: Misdiagnosis and Self-Report Measures

The coexistence of traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD) remains a controversial issue in the literature. To address this controversy, we focused primarily on the civilian-related literature of TBI and PTSD. Some investigators have argued that individuals who had been rendered unconscious or suffered amnesia due to a TBI are unable to develop PTSD because they would be unable to consciously experience the symptoms of fear, helplessness, and horror associated with the development of PTSD. Other investigators have reported that individuals who sustain TBI, regardless of its severity, can develop PTSD even in the context of prolonged unconsciousness. A careful review of the methodologies employed in these studies reveals that investigators who relied on clinical interviews of TBI patients to diagnose PTSD found little or no evidence of PTSD. In contrast, investigators who relied on PTSD questionnaires to diagnose PTSD found considerable evidence of PTSD. Further analysis revealed that many of the TBI patients who were initially diagnosed with PTSD according to self-report questionnaires did not meet the diagnostic criteria for PTSD upon completion of a clinical interview. In particular, patients with severe TBI were often misdiagnosed with PTSD. A number of investigators found that many of the severe TBI patients failed to follow the questionnaire instructions and erroneously endorsed PTSD symptoms because of their cognitive difficulties. Because PTSD questionnaires are not designed to discriminate between PTSD and TBI symptoms or determine whether a patient's responses are accurate or exaggerated, studies that rely on self-report questionnaires to evaluate PTSD in TBI patients are at risk of misdiagnosing PTSD. Further research should evaluate the degree to which misdiagnosis of PTSD occurs in individuals who have sustained mild TBI.

Borderline personality disorder: hypothalamus pituitary adrenal axis and findings from neuroimaging studies

Borderline personality disorder (BPD) is a complex and serious mental disorder that is commonly seen psychiatric practice. Although stress, especially early life stress, seems to be associated with the development of the disorder, there has been far less research on the function of the hypothalamic-pituitary-adrenal (HPA) axis in BPD, compared to other psychiatric disorders, such as major depressive disorder and post-traumatic stress disorder. Stress has been suggested to exert damaging effects on the brain, particularly the hippocampus; therefore, neuroimaging studies yield important insight into the neurobiology of BPD. This article reviews research on the HPA axis and neuroimaging studies in BPD and aims to integrate these findings.