Intrusive Traumatic Re-Experiencing Domain: Functional Connectivity Feature Classification by the ENIGMA PTSD Consortium.

Background: Intrusive traumatic re-experiencing domain (ITRED) was recently introduced as a novel perspective on posttraumatic psychopathology, proposing to focus research of posttraumatic stress disorder (PTSD) on the unique symptoms of intrusive and involuntary re-experiencing of the trauma, namely, intrusive memories, nightmares, and flashbacks. The aim of the present study was to explore ITRED from a neural network connectivity perspective. Methods: Data were collected from 9 sites taking part in the ENIGMA (Enhancing Neuro Imaging Genetics through Meta Analysis) PTSD Consortium (n= 584) and included itemized PTSD symptom scores and resting-state functional connectivity (rsFC) data. We assessed the utility of rsFC in classifying PTSD, ITRED-only (no PTSD diagnosis), and trauma-exposed (TE)-only (no PTSD or ITRED) groups using a machine learning approach, examining well-known networks implicated in PTSD. A random forest classification model was built on a training set using cross-validation, and the averaged cross-validation model performance for classification was evaluated using the area under the curve. The model was tested using a fully independent portion of the data (test dataset), and the test area under the curve was evaluated. Results: rsFC signatures differentiated TE-only participants from PTSD and ITRED-only participants at about 60% accuracy. Conversely, rsFC signatures did not differentiate PTSD from ITRED-only individuals (45% accuracy). Common features differentiating TE-only participants from PTSD and ITRED-only participants mainly involved default mode network-related pathways. Some unique features, such as connectivity within the frontoparietal network, differentiated TE-only participants from one group (PTSD or ITRED-only) but to a lesser extent from the other group. Conclusions: Neural network connectivity supports ITRED as a novel neurobiologically based approach to classifying posttrauma psychopathology.

Facilitating the transition home after military deployment: a systematic literature review of post-deployment adaptation programmes.

Background: Many countries pay special attention to the transition of their military personnel from deployment to home via post-deployment adaptation programmes (PDAPs). Objective: This systematic review aims to provide a structured analysis of structure, process, and outcomes based on available empirical evidence for PDAPs. Methods: A systematic literature search was performed to identify original peer-reviewed studies on PDAP in six databases (MEDLINE, Embase, PsycINFO, Cochrane Central Register of Controlled Trials, PTSDPubs, and OpenGrey). The overall risk of bias of the articles was assessed using GRADE guidelines. The literature was analysed in its description of PDAP structure, process, and outcomes. In addition, when effects were reported, these were extracted. Results: The search resulted in 1535 unique records that were screened for eligibility; 16 articles were included, of which only three showed low risk of bias according to GRADE. Few studies clearly described and investigated PDAP structure elements (i.e. combat exposure), process elements (i.e. who delivered the intervention), and other outcome elements (i.e. adjustment issues). Most articles included some form of third location decompression (N = 10; psychoeducation and time to rest and relax on a location that is not in the mission theatre or at home) and Battlemind (N = 4; interactive training focusing on how to adapt skills and cognitions after deployment at home). The results suggest positive mental health effects and satisfaction of these two types of PDAP, although the evidence is poor. Conclusions: Empirical, high-quality evidence for PDAP is scarce. In addition, the existing literature reveals a lack of systematic method in describing the goals of PDAP and the ways of achieving these. This leads to incomparability between studies and hinders the building of a knowledge base on PDAPs. A structure is proposed for describing the structure, process, and outcomes of PDAPs with measured effects. HIGHLIGHTS: High -quality evidence for post-deployment adaptation programmes is scarce.Programme structure, process, and aims with measured effects are not delineated.Positive mental health effects are reported for Battlemind and third location decompression.

Antecedentes: Muchos países ponen especial atención a la transición de su personal militar desde el despliegue al hogar por medio de los programas de adaptación luego del despliegue (PDAPs en su sigla en inglés).Objetivo: Esta revisión sistemática busca proveer un análisis estructurado de la estructura, proceso y resultados basados en la evidencia empírica disponible para PDAPs.Método: Se realizó una búsqueda sistemática de la literatura para identificar estudios originales revisados por pares en PDAP en seis bases de datos (MEDLINE, Embase, PsycINFO, Cochrane Central Register of Controlled Trials, PTSDPubs y OpenGrey). El riesgo de sesgo general de los artículos fue evaluado usando las guías de GRADE. La literatura fue analizada en su descripción de la estructura, proceso y resultados de PDAP. Además, se extrajeron los efectos cuando fueron reportados.Resultados: La búsqueda resultó en 1535 registros únicos que fueron evaluados por la idoneidad; 16 artículos fueron incluidos, de los cuales solo 3 mostraron bajo riesgo de sesgo de acuerdo con GRADE. Pocos estudios describieron e investigaron claramente los elementos de la estructura (por ej., exposición a combate), los elementos del proceso (por ej., quien entrego la intervención), y otros elementos de los resultados (por ej., problemas de adaptacion). La mayoría de los artículos incluyeron alguna forma de descompresión en un tercer lugar (N = 10; psicoeducación y tiempo para descansar y relajarse en un lugar que no sea el teatro de la misión o en el hogar) y Mentalidad de Batalla [Battlemind] (N = 4; un entrenamiento interactivo centrado en cómo adaptar habilidades y cogniciones luego del despliegue en el hogar). Los resultados sugieren efectos positivos para la salud mental y satisfacción de esos dos tipos de PDAP, aunque la evidencia es escasa.Conclusiones: La evidencia empírica de alta calidad para PDAP es escasa. Además, la literatura existente revela una carencia de un método sistemático en describir los objetivos de PDAP y las formas de lograrlos. Esto lleva a que los estudios no sean comparables y limita la construcción de una base de conocimiento sobre PDAP. Se propone una estructura para describir la estructura, proceso, y los resultados de PDAPs con los efectos medidos.

Spontaneous brain activity, graph metrics, and head motion related to prospective post-traumatic stress disorder trauma-focused therapy response.

Introduction: Trauma-focused psychotherapy for post-traumatic stress disorder (PTSD) is effective in about half of all patients. Investigating biological systems related to prospective treatment response is important to gain insight in mechanisms predisposing patients for successful intervention. We studied if spontaneous brain activity, brain network characteristics and head motion during the resting state are associated with future treatment success. Methods: Functional magnetic resonance imaging scans were acquired from 46 veterans with PTSD around the start of treatment. Psychotherapy consisted of trauma-focused cognitive behavioral therapy (tf-CBT), eye movement desensitization and reprocessing (EMDR), or a combination thereof. After intervention, 24 patients were classified as treatment responders and 22 as treatment resistant. Differences between groups in spontaneous brain activity were evaluated using amplitude of low-frequency fluctuations (ALFF), while global and regional brain network characteristics were assessed using a minimum spanning tree (MST) approach. In addition, in-scanner head motion was assessed. Results: No differences in spontaneous brain activity and global network characteristics were observed between the responder and non-responder group. The right inferior parietal lobule, right putamen and left superior parietal lobule had a more central position in the network in the responder group compared to the non-responder group, while the right dorsolateral prefrontal cortex (DLPFC), right inferior frontal gyrus and left inferior temporal gyrus had a less central position. In addition, responders showed less head motion. Discussion: These results show that areas involved in executive functioning, attentional and action processes, learning, and visual-object processing, are related to prospective PTSD treatment response in veterans. In addition, these findings suggest that involuntary micromovements may be related to future treatment success.

Psychological factors for the onset of depression: a meta-analysis of prospective studies.

OBJECTIVES: A comprehensive overview of the evidence for factors derived from leading psychological theories of the onset of major depressive disorder (MDD) that underpin psychological interventions is scarce . We aimed to systematically investigate the prospective evidence for factors derived from the behavioural, cognitive, diathesis-stress, psychodynamic and personality-based theories for the first onset of MDD. DESIGN: Systematic review and meta-analysis. METHODS: Databases PubMed, PsycINFO, Cochrane and Embase and published articles were systematically searched from inception up to August 2019. Prospective, longitudinal studies that investigated theory-derived factors before the first onset of MDD, established by a clinical interview, were included. Screening, selection and data extraction of articles were conducted by two screeners. The Grading of Recommendations Assessment, Development and Evaluation criteria were used to estimate level of confidence and risk of bias. Meta-analysis was conducted using random-effects models and mixed-method subgroup analyses. PRIMARY AND SECONDARY OUTCOME MEASURES: Effect size of a factor predicting the onset of MDD (OR, risk ratio or HR). RESULTS: From 42 133 original records published to August 2019, 26 studies met the inclusion criteria. Data were only available for the cognitive (n=6585) and personality-based (n=14 394) theories. Factors derived from cognitive theories and personality-based theories were related to increased odds of MDD onset (pooled OR=2.12, 95% CI: 1.12 to 4.00; pooled OR=2.43, 95% CI: 1.41 to 4.19). Publication bias and considerable heterogeneity were observed. CONCLUSION: There is some evidence that factors derived from cognitive and personality-based theories indeed predict the onset of MDD (ie, dysfunctional attitudes and negative emotionality). There were no studies that prospectively studied factors derived from psychodynamic theories and not enough studies to examine the robust evidence for behavioural and diathesis-stress theories. Overall, the prospective evidence for psychological factors of MDD is limited, and more research on the leading psychological theories is needed. PROSPERO REGISTRATION NUMBER: CRD42017073975.

Altered white matter microstructural organization in posttraumatic stress disorder across 3047 adults: results from the PGC-ENIGMA PTSD consortium.

A growing number of studies have examined alterations in white matter organization in people with posttraumatic stress disorder (PTSD) using diffusion MRI (dMRI), but the results have been mixed which may be partially due to relatively small sample sizes among studies. Altered structural connectivity may be both a neurobiological vulnerability for, and a result of, PTSD. In an effort to find reliable effects, we present a multi-cohort analysis of dMRI metrics across 3047 individuals from 28 cohorts currently participating in the PGC-ENIGMA PTSD working group (a joint partnership between the Psychiatric Genomics Consortium and the Enhancing NeuroImaging Genetics through Meta-Analysis consortium). Comparing regional white matter metrics across the full brain in 1426 individuals with PTSD and 1621 controls (2174 males/873 females) between ages 18-83, 92% of whom were trauma-exposed, we report associations between PTSD and disrupted white matter organization measured by lower fractional anisotropy (FA) in the tapetum region of the corpus callosum (Cohen's d = -0.11, p = 0.0055). The tapetum connects the left and right hippocampus, for which structure and function have been consistently implicated in PTSD. Results were consistent even after accounting for the effects of multiple potentially confounding variables: childhood trauma exposure, comorbid depression, history of traumatic brain injury, current alcohol abuse or dependence, and current use of psychotropic medications. Our results show that PTSD may be associated with alterations in the broader hippocampal network.

Successful treatment of post-traumatic stress disorder reverses DNA methylation marks.

Epigenetic mechanisms play a role in the detrimental effects of traumatic stress and the development of post-traumatic stress disorder (PTSD). However, it is unknown whether successful treatment of PTSD restores these epigenetic marks. This study investigated longitudinal changes of blood-based genome-wide DNA methylation levels in relation to trauma-focused psychotherapy for PTSD in soldiers that obtained remission (N = 21), non-remitted PTSD patients (N = 23), and trauma-exposed military controls (N = 23). In an independent prospective cohort, we then examined whether these DMRs were also relevant for the development of deployment-related PTSD (N = 85). Successful treatment of PTSD was accompanied by significant changes in DNA methylation at 12 differentially methylated regions (DMRs) in the genes: APOB, MUC4, EDN2, ZFP57, GPX6, CFAP45, AFF3, TP73, UBCLP1, RPL13P, and two intergenic regions (p values < 0.0001 were confirmed using permutation and sensitivity analyses). Of the 12 DMRs related to PTSD symptom reduction, consistent prospective evidence was found for ZFP57 methylation changes related to changing PTSD symptoms (B = -0.84, t = -2.49, p = 0.014). Increasing ZFP57 methylation related to PTSD symptom reduction was present over and above the relation with symptoms, suggesting that psychological treatments exert biological effects independent of symptom reduction. Together, these data provide longitudinal evidence that ZFP57 methylation is involved in both the development and successful treatment of deployment-related PTSD. This study is a first step to disentangle the interaction between psychological and biological systems to identify genomic regions relevant for the etiology and treatment of stress-related disorders such as PTSD.

Prospective biomarkers of major depressive disorder: a systematic review and meta-analysis.

Leading biological hypotheses propose that biological changes may underlie major depressive disorder onset and relapse/recurrence. Here, we investigate if there is prospective evidence for biomarkers derived from leading theories. We focus on neuroimaging, gastrointestinal factors, immunology, neurotrophic factors, neurotransmitters, hormones, and oxidative stress. Searches were performed in Pubmed, Embase and PsychInfo for articles published up to 06/2019. References and citations of included articles were screened to identify additional articles. Inclusion criteria were having an MDD diagnosis as outcome, a biomarker as predictor, and prospective design search terms were formulated accordingly. PRISMA guidelines were applied. Meta-analyses were performed using a random effect model when three or more comparable studies were identified, using a random effect model. Our search resulted in 67,464 articles, of which 75 prospective articles were identified on: Neuroimaging (N = 24), Gastrointestinal factors (N = 1), Immunology (N = 8), Neurotrophic (N = 2), Neurotransmitters (N = 1), Hormones (N = 39), Oxidative stress (N = 1). Meta-analyses on brain volumes and immunology markers were not significant. Only cortisol (N = 19, OR = 1.294, p = 0.024) showed a predictive effect on onset/relapse/recurrence of MDD, but not on time until MDD onset/relapse/recurrence. However, this effect disappeared when studies including participants with a baseline clinical diagnosis were removed from the analyses. Other studies were too heterogeneous to compare. Thus, there is a lack of evidence for leading biological theories for onset and maintenance of depression. Only cortisol was identified as potential predictor for MDD, but results are influenced by the disease state. High-quality (prospective) studies on MDD are needed to disentangle the etiology and maintenance of MDD.

Individual prediction of psychotherapy outcome in posttraumatic stress disorder using neuroimaging data.

Trauma-focused psychotherapy is the first-line treatment for posttraumatic stress disorder (PTSD) but 30-50% of patients do not benefit sufficiently. We investigated whether structural and resting-state functional magnetic resonance imaging (MRI/rs-fMRI) data could distinguish between treatment responders and non-responders on the group and individual level. Forty-four male veterans with PTSD underwent baseline scanning followed by trauma-focused psychotherapy. Voxel-wise gray matter volumes were extracted from the structural MRI data and resting-state networks (RSNs) were calculated from rs-fMRI data using independent component analysis. Data were used to detect differences between responders and non-responders on the group level using permutation testing, and the single-subject level using Gaussian process classification with cross-validation. A RSN centered on the bilateral superior frontal gyrus differed between responders and non-responder groups (PFWE < 0.05) while a RSN centered on the pre-supplementary motor area distinguished between responders and non-responders on an individual-level with 81.4% accuracy (P < 0.001, 84.8% sensitivity, 78% specificity and AUC of 0.93). No significant single-subject classification or group differences were observed for gray matter volume. This proof-of-concept study demonstrates the feasibility of using rs-fMRI to develop neuroimaging biomarkers for treatment response, which could enable personalized treatment of patients with PTSD.

Psychological theories of depressive relapse and recurrence: A systematic review and meta-analysis of prospective studies.

Psychological factors hypothesized to account for relapse of major depressive disorder (MDD) roughly originate from five main theories: Cognitive, diathesis-stress, behavioural, psychodynamic, and personality-based. In a meta-analysis we investigated prospective, longitudinal evidence for these leading psychological theories and their factors in relation to depressive relapse. Included studies needed to establish history of MDD and prospective depressive relapse through a clinical interview, have a longitudinal and prospective design, and measure at least one theory-derived factor before relapse. We identified 66 eligible articles out of 43,586 records published up to November 2018. Pooled odds ratios (OR) indicated a significant relationship between the cognitive, behavioural, and personality-based theories and depressive relapse (cognitive: k = 17, OR = 1.24, 95% CI = 1.10-1.40; behavioural, k = 8, OR = 1.15, 95% CI = 1.05-1.25; personality: k = 12, OR = 1.26, 95% CI = 1.02-1.54), but not for the psychodynamic theories (k = 4, OR = 1.29, 95% CI = 0.83-1.99). Pooled hazard ratios of the theories were not significant. There were no articles identified for the diathesis-stress theories. To conclude, there is a restricted number of prospective studies, and some evidence that the cognitive, behavioural, and personality-based theories indeed partially account for depressive relapse.

The relation between anxious personality traits and fear generalization in healthy subjects: A systematic review and meta-analysis.

BACKGROUND: Anxious personality characteristics form a risk factor for anxiety disorders. A proposed mechanistic pathway is that anxious personality could lead to greater vulnerability by increasing fear generalization. Here, we investigate if there is evidence for this relationship before the onset of pathological anxiety, with a meta-analysis in healthy subjects. METHODS: Our search (anxious personality & fear generalization) was performed in PubMed, PsychInfo, and Embase and via snowballing. RESULTS: In total, 4892 studies were screened and 19 studies (1348 participants) were included in the current review (meta-analysis: 18 studies, 1310 participants). The meta-analysis showed a significant, small, positive relationship between anxious personality and fear generalization (r = .19, 95%CI [.126, .260], p <.001). No moderators of the relationship were identified. CONCLUSIONS: The identified robust relation suggests that people who score high on anxious personality have a somewhat stronger tendency to generalize fear to safe or novel situations. This might explain their vulnerability to anxiety disorders mechanistically, yet future (prospective) studies are warranted to confirm the hypothesized directionality of this effect.

The effects of cognitive-behavior therapy for depression on repetitive negative thinking: A meta-analysis.

It is not clear if treatments for depression targeting repetitive negative thinking (RNT: rumination, worry and content-independent perseverative thinking) have a specific effect on RNT resulting in better outcomes than treatments that do not specifically target rumination. We conducted a systematic search of PsycINFO, PubMed, Embase and the Cochrane library for randomized trials in adolescents, adults and older adults comparing CBT treatments for (previous) depression with control groups or with other treatments and reporting outcomes on RNT. Inclusion criteria were met by 36 studies with a total of 3307 participants. At post-test we found a medium-sized effect of any treatment compared to control groups on RNT (g = 0.48; 95% CI: 0.37-0.59). Rumination-focused CBT: g = 0.76, <0.01; Cognitive Control Training: g = 0.62, p < .01; CBT: g = 0.57, p < .01; Concreteness training: g = 0.53, p < .05; and Mindfulness-based Cognitive Therapy: g = 0.42, p < .05 had medium sized and significantly larger effect sizes than other types of treatment (i.e., anti-depressant medication, light therapy, engagement counseling, life review, expressive writing, yoga) (g = 0.14) compared to control groups. Effects on RNT at post-test were strongly associated with the effects on depression severity and this association was only significant in RNT-focused CBT. Our results suggest that in particular RNT-focused CBT may have a more pronounced effect on RNT than other types of interventions. Further mediation and mechanistic studies to test the predictive value of reductions in RNT following RNT-focused CBT for subsequent depression outcomes are called for.

Predicting Treatment Outcome in PTSD: A Longitudinal Functional MRI Study on Trauma-Unrelated Emotional Processing.

In about 30-50% of patients with posttraumatic stress disorder (PTSD), symptoms persist after treatment. Although neurobiological research has advanced our understanding of PTSD, little is known about the neurobiology underlying persistence of PTSD. Two functional MRI scans were collected from 72 war veterans with and without PTSD over a 6- to 8-month interval, during which PTSD patients received trauma-focused therapy. All participants performed a trauma-unrelated emotional processing task in the scanner. Based on post-treatment symptom severity, a distinction was made between remitted and persistent patients. Behavioral and imaging measures of trauma-unrelated emotional processing were compared between the three groups (remitted patients, N=21; persistent patients, N=22; and combat controls, N=25) with repeated-measures (pre- and post-treatment) analyses. Second, logistic regression was used to predict treatment outcome. Before and after treatment, persistent patients showed a higher dorsal anterior cingulate cortex (dACC) and insula response to negative pictures compared with remitted patients and combat controls. Before treatment, persistent patients showed increased amygdala activation in response to negative pictures compared with remitted patients. The remitted patients and combat controls did not differ on the behavioral or imaging measures. Finally, higher dACC, insula, and amygdala activation before treatment were significant predictors of symptom persistence. Our results highlight a pattern of brain activation that may predict poor response to PTSD treatment. These findings can contribute to the development of alternative or additional therapies. Further research is needed to elucidate the heterogeneity within PTSD and describe how differences in neural function are related to treatment outcome. Such approaches are critical for defining parameters to customize PTSD treatment and improve treatment response rates.

Treatment Outcome-Related White Matter Differences in Veterans with Posttraumatic Stress Disorder.

Posttraumatic stress disorder (PTSD) is a debilitating disorder that has been associated with brain abnormalities, including white matter alterations. However, little is known about the effect of treatment on these brain alterations. To investigate the course of white matter alterations in PTSD, we used a longitudinal design investigating treatment effects on white matter integrity using diffusion tensor imaging (DTI). Diffusion tensor and magnetization transfer images were obtained pre- and posttreatment from veterans with (n=39) and without PTSD (n=22). After treatment, 16 PTSD patients were remitted, and 23 had persistent PTSD based on PTSD diagnosis. The dorsal and hippocampal cingulum bundle, stria terminalis, and fornix were investigated as regions of interest. Exploratory whole-brain analyses were also performed. Groups were compared with repeated-measures ANOVA for fractional anisotropy (FA), and magnetization transfer ratio. Persistently symptomatic PTSD patients had increasing FA of the dorsal cingulum over time, and at reassessment these FA values were higher than both combat controls and the remitted PTSD group. Group-by-time interactions for FA were found in the hippocampal cingulum, fornix, and stria terminalis, posterior corona radiata, and superior longitudinal fasciculus. Our results indicate that higher FA of the dorsal cingulum bundle may be an acquired feature of persistent PTSD that develops over time. Furthermore, treatment might have differential effects on the hippocampal cingulum, fornix, stria terminalis, posterior corona radiata, and superior longitudinal fasciculus in remitted vs persistent PTSD patients. This study contributes to a better understanding of the neural underpinnings of PTSD treatment outcome.

Neural correlates of inhibition and contextual cue processing related to treatment response in PTSD.

Thirty to fifty percent of posttraumatic stress disorder (PTSD) patients do not respond to treatment. Understanding the neural mechanisms underlying treatment response could contribute to improve response rates. PTSD is often associated with decreased inhibition of fear responses in a safe environment. Importantly, the mechanism of effective treatment (psychotherapy) relies on inhibition and so-called contextual cue processing. Therefore, we investigate inhibition and contextual cue processing in the context of treatment. Forty-one male war veterans with PTSD and 22 healthy male war veterans (combat controls) were scanned twice with a 6- to 8-month interval, in which PTSD patients received treatment (psychotherapy). We distinguished treatment responders from nonresponders on the base of percentage symptom decrease. Inhibition and contextual cue processing were assessed with the stop-signal anticipation task. Behavioral and functional MRI measures were compared between PTSD patients and combat controls, and between responders and nonresponders using repeated measures analyses. PTSD patients showed behavioral and neural deficits in inhibition and contextual cue processing at both time points compared with combat controls. These deficits were unaffected by treatment; therefore, they likely represent vulnerability factors or scar aspects of PTSD. Second, responders showed increased pretreatment activation of the left inferior parietal lobe (IPL) during contextual cue processing compared with nonresponders. Moreover, left IPL activation predicted percentage symptom improvement. The IPL has an important role in contextual cue processing, and may therefore facilitate the effect of psychotherapy. Hence, increased left IPL activation may represent a potential predictive biomarker for PTSD treatment response.

Resting state functional connectivity of the anterior cingulate cortex in veterans with and without post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is an anxiety disorder that is associated with structural and functional alterations in several brain areas, including the anterior cingulate cortex (ACC). Here, we examine resting state functional connectivity of ACC subdivisions in PTSD, using a seed-based approach. Resting state magnetic resonance images were obtained from male veterans with (n = 31) and without (n = 25) PTSD, and healthy male civilian controls (n = 25). Veterans with and without PTSD (combat controls) had reduced functional connectivity compared to healthy controls between the caudal ACC and the precentral gyrus, and between the perigenual ACC and the superior medial gyrus and middle temporal gyrus. Combat controls had increased connectivity between the rostral ACC and precentral/middle frontal gyrus compared to PTSD patients and healthy civilian controls. The resting state functional connectivity differences in the perigenual ACC network reported here indicate that veterans differ from healthy controls, potentially due to military training, deployment, and/or trauma exposure. In addition, specific alterations in the combat controls may potentially be related to resilience. These results underline the importance of distinguishing trauma-exposed (combat) controls from healthy civilian controls when studying PTSD.

Impaired right inferior frontal gyrus response to contextual cues in male veterans with PTSD during response inhibition.

BACKGROUND: Posttraumatic stress disorder (PTSD) is often associated with impaired fear inhibition and decreased safety cue processing; however, studies capturing the cognitive aspect of inhibition and contextual cue processing are limited. In this fMRI study, the role of contextual cues in response inhibition was investigated. METHODS: Male medication-naive war veterans with PTSD, male control veterans (combat controls) and healthy nonmilitary men (healthy controls) underwent fMRI while performing the stop-signal anticipation task (SSAT). The SSAT evokes 2 forms of response inhibition: reactive inhibition (outright stopping) and proactive inhibition (anticipation of stopping based on contextual cues). RESULTS: We enrolled 28 veterans with PTSD, 26 combat controls and 25 healthy controls in our study. Reduced reactive inhibition was observed in all veterans, both with and without PTSD, but not in nonmilitary controls, whereas decreased inhibition of the left pre/postcentral gyrus appeared to be specifically associated with PTSD. Impaired behavioural proactive inhibition was also specific to PTSD. Furthermore, the PTSD group showed a reduced right inferior frontal gyrus response during proactive inhibition compared with the combat control group. LIMITATIONS: Most patients with PTSD had comorbid psychiatric disorders, but such comorbidity is common in patients with PTSD. Also, the education level (estimate of intelligence) of participants, but not of their parents, differed among the groups. CONCLUSION: Our findings of reduced proactive inhibition imply that patients with PTSD show reduced contextual cue processing. These results complement previous findings on fear inhibition and demonstrate that contextual cue processing in patients with PTSD is also reduced during cognitive processes, indicating a more general deficit.

Altered functional connectivity in posttraumatic stress disorder with versus without comorbid major depressive disorder: a resting state fMRI study.

Posttraumatic stress disorder (PTSD) is an anxiety disorder that is often diagnosed with comorbid depressive disorder. Therefore, neuroimaging studies investigating PTSD typically include both patients with and without comorbid depression. Differences in activity of the anterior cingulate cortex (ACC) and insula have been shown to differentiate PTSD patients with and without major depressive disorder (MDD). Whether or not comorbid MDD affects resting state functional connectivity of PTSD patients has not been investigated to our knowledge. Here, resting state functional connectivity of PTSD patients with (PTSD+MDD; n=27) and without (PTSD-MDD; n=23) comorbid MDD was investigated. The subgenual ACC and insula were investigated as seed regions. Connectivity between the subgenual ACC and perigenual parts of the ACC was increased in PTSD+MDD versus PTSD-MDD. Reduced functional connectivity of the subgenual ACC with the thalamus was found in the PTSD+MDD group versus the PTSD-MDD group. These results remained significant after controlling for PTSD severity. In addition, the PTSD+MDD group showed reduced functional connectivity of the insula with the hippocampus compared to the PTSD-MDD group. However, this cluster was no longer significantly different when controlling for PTSD severity. Thus, resting state functional connectivity of the subgenual ACC may distinguish PTSD+MDD from PTSD-MDD. As PTSD patients with comorbid MDD are more treatment resistant, this result may be important for treatment development.

Neural correlates of personality: an integrative review.

This review examines the neural correlates of Gray's model (Gray and McNaughton, 2000; McNaughton and Corr, 2004), supplemented by a fourth dimension: constraint (Carver, 2005). The purpose of this review is to summarize findings from fMRI studies that tap on neural correlates of personality aspects in healthy subjects, in order to provide insight into the neural activity underlying human temperament. BAS-related personality traits were consistently reported to correlate positively to activity of the ventral and dorsal striatum and ventral PFC in response to positive stimuli. FFFS and BIS-related personality traits are positively correlated to activity in the amygdala in response to negative stimuli. There is limited evidence that constraint is associated with PFC and ACC activity. In conclusion, functional MRI research sheds some light on the specific neural networks underlying personality. It is clear that more sophisticated task paradigms are required, as well as personality questionnaires that effectively differentiate between BAS, FFFS, BIS, and constraint. Further research is proposed to potentially reveal new insight in the neural subsystems governing basic human behavior.