Brain age prediction using combined deep convolutional neural network and multi-layer perceptron algorithms.

The clinical applications of brain age prediction have expanded, particularly in anticipating the onset and prognosis of various neurodegenerative diseases. In the current study, we proposed a deep learning algorithm that leverages brain structural imaging data and enhances prediction accuracy by integrating biological sex information. Our model for brain age prediction, built on deep neural networks, employed a dataset of 3004 healthy subjects aged 18 and above. The T1-weighted images were minimally preprocessed and analyzed using the convolutional neural network (CNN) algorithm. The categorical sex information was then incorporated using the multi-layer perceptron (MLP) algorithm. We trained and validated both a CNN-only algorithm (utilizing only brain structural imaging data), and a combined CNN-MLP algorithm (using both structural brain imaging data and sex information) for age prediction. By integrating sex information with T1-weighted imaging data, our proposed CNN-MLP algorithm outperformed not only the CNN-only algorithm but also established algorithms, such as brainageR, in prediction accuracy. Notably, this hybrid CNN-MLP algorithm effectively distinguished between mild cognitive impairment and Alzheimer's disease groups by identifying variances in brain age gaps between them, highlighting the algorithm's potential for clinical application. Overall, these results underscore the enhanced precision of the CNN-MLP algorithm in brain age prediction, achieved through the integration of sex information.

Changes of regional cerebral blood flow after deep brain stimulation in cervical dystonia.

INTRODUCTION: Cervical dystonia is considered as a network disorder affecting various brain regions in recent days. Presumably, deep brain stimulation (DBS) of the internal segment of globus pallidus (GPi) may exert therapeutic effects for cervical dystonia through modulation of the aberrant brain networks. In the present study, we investigated postoperative regional cerebral blood flow (rCBF) changes after GPi DBS using single-photon emission computed tomography (SPECT) to identify significant activity changes in several relevant brain areas of cervical dystonia patients. METHODS: A total of 9 patients with idiopathic cervical dystonia were recruited, and SPECT scans were conducted at baseline and 3 months after the bilateral GPi DBS. Voxel-wise changes of rCBF were analyzed using Statistical Parametric Mapping. Symptom severity of dystonia was measured using Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) at the baseline, and 1 week, and 3 months after GPi DBS. RESULTS: At the 3-month follow-up after DBS, rCBF was increased in the left pons and right postcentral gyrus and decreased in the left middle frontal gyrus, left cerebellum, right putamen and pallidum, and left thalamus (p < 0.001). Severity of cervical dystonia assessed by TWSTRS was significantly decreased at 1-week and 3-month follow-up (p = 0.004). CONCLUSIONS: Clinical improvement of cervical dystonia after GPi DBS may be accompanied by rCBF changes in several brain areas of the cortico-basal ganglia-cerebellar network which are important for sensorimotor integration.

Regional Cerebral Blood Flow Correlates of Neuropsychiatric Symptom Domains in Early Alzheimer's Disease.

Although various neuropsychiatric symptoms are frequently accompanied with Alzheimer's disease (AD) and pose a substantial burden to both patients and caregivers, their neurobiological underpinnings remain unclear. This study investigated associations between regional cerebral blood flow (rCBF) and neuropsychiatric symptom domains in early AD. A total of 59 patients with early AD underwent brain technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) single-photon emission computed tomography (SPECT) scans. Neuropsychiatric symptoms were assessed by the Neuropsychiatric Inventory and clustered into the affective, apathy, hyperactivity, and psychotic domains. A voxel-wise multiple regression analysis was performed with four domain scores as independent variables and age, sex, and Mini-Mental State Examination scores as covariates. The affective domain score was negatively correlated with rCBF in the prefrontal cortex, thalamus, and caudate. The apathy domain score showed inverse correlations with rCBF in the prefrontal and pre/postcentral gyri and midbrain. Patients with higher hyperactivity domain scores had increased rCBF in the prefrontal and temporal lobes. The psychotic symptom domain was positively correlated with rCBF in the cuneus and negatively associated with rCBF in the prefrontal, cingulate, and occipital regions and putamen. The score of each neuropsychiatric symptom domain showed the differential correlates of brain perfusion, while altered rCBF in the prefrontal cortex was found in all domains. Although preliminary, our results may suggest common and distinct patterns of rCBF underlying neuropsychiatric symptoms in early AD. Further studies with larger samples and control participants are warranted to confirm these findings.

Changes in Prefrontal Gamma-Aminobutyric Acid and Perfusion After the Computerized Relaxation Training in Women With Psychological Distress: A Preliminary Report.

Computerized relaxation training has been suggested as an effective and easily accessible intervention for individuals with psychological distress. To better elucidate the neural mechanism that underpins the effects of relaxation training, we investigated whether a 10-session computerized relaxation training program changed prefrontal gamma-aminobutyric acid (GABA) levels and cerebral blood flow (CBF) in women with psychological distress. We specifically focused on women since they were reported to be more vulnerable to develop stress-related disorders than men. Nineteen women with psychological distress but without a diagnosis of psychiatric disorders received the 10-day computerized relaxation training program that consisted of 30-min cognitive-relaxation training and 10-min breathing-relaxation training per day. At baseline and post-intervention, perceived stress levels, anxiety, fatigue, and sleep quality were assessed by self-report questionnaires. Brain magnetic resonance spectroscopy and arterial spin labeling scans were also performed before and after the intervention to evaluate GABA levels and relative CBF in the prefrontal region. Levels of perceived stress (t = 4.02, P < 0.001), anxiety (z = 2.33, P = 0.02), fatigue (t = 3.35, P = 0.004), and sleep quality (t = 4.14, P < 0.001) improved following 10 sessions of computerized relaxation training, resulting in a significant relief in composite scores of stress-related symptoms (t = -5.25, P < 0.001). The prefrontal GABA levels decreased (t = 2.53, P = 0.02), while relative CBF increased (t = -3.32, P = 0.004) after the intervention. In addition, a greater increase in relative prefrontal CBF was associated with better composite scores of stress-related symptoms following the intervention (t = 2.22, P = 0.04). The current findings suggest that computerized relaxation training may improve stress-related symptoms through modulating the prefrontal GABA levels and CBF in women with psychological distress.

Elevating the level of hypoxia inducible factor may be a new potential target for the treatment of depression.

Hypoxia inducible factor-1 (HIF-1) is a transcriptional factor that regulates gene expressions in response to decreased oxygen levels in the tissue, or hypoxia. HIF-1 exerts protective effects against hypoxia by mediating mitochondrial metabolism and consequently reducing oxidative stress. Recently, increased levels of oxidative stress and abnormal energy metabolism in the brain have been suggested to play essential roles in the pathogenesis of depression. Given that HIF-1 activates creatine metabolism and increases phosphocreatine levels in the intestinal epithelial cells, we assume that HIF-1 may induce similar processes in the brain. Elevated phosphocreatine levels in the brain, as measured by magnetic resonance spectroscopy, were associated with better treatment response to the antidepressants in individuals with depression. In addition, oral creatine supplements, which led to increased phosphocreatine levels in the brain, also enhanced the effects of antidepressants in individuals with depression. As such, we hypothesized that increasing the HIF-1, which potentially facilitates creatine metabolism in the brain, might be a new therapeutic target in depression. With this regard, we suggested that interventions to elevate the HIF-1 levels in the brain, including the intermittent hypoxia conditioning and hyperbaric oxygen therapy, might be considered as new additional treatments for depression.

Shorter sleep duration is associated with lower GABA levels in the anterior cingulate cortex.

BACKGROUND: Alterations in the levels of gamma-aminobutyric acid (GABA) and glutamate + glutamine (Glx), which are major inhibitory and excitatory neurotransmitters, respectively, are frequently associated with insomnia. Previous reports also suggested the involvement of the anterior cingulate cortex (ACC) and medial prefrontal cortex (mPFC) in insomnia and shorter sleep duration. In the current study, we investigated whether the GABA and Glx levels were altered in the ACC/mPFC in subclinical insomnia while focusing on the sleep duration. METHODS: We examined levels of GABA and Glx in the ACC/mPFC of the brain with magnetic resonance spectroscopy in 166 individuals with subjective sleep complaints but without a diagnosis of insomnia. Participants were divided into two groups according to sleep duration (≥6 h/night: n = 79 vs. < 6 h/night: n = 74), which was measured using a wrist-worn actigraphy. Working memory function and overall subjective sleep quality were assessed with a computerized neuropsychological test and self-report questionnaire, respectively. RESULTS: GABA levels in the ACC/mPFC were lower in the shorter sleep duration group relative to the longer sleep duration group (t = -2.21, p = 0.03). Glx levels did not differ between the two groups (t = -0.20, p = 0.84). Lower GABA levels were associated with lower spatial working memory performance in the shorter sleep duration group (ß = -0.21, p = 0.03), but not the longer sleep duration group (ß = 0.04, p = 0.72). CONCLUSION: Shorter sleep duration was associated with lower GABA levels in the ACC/mPFC. These findings may provide insight into the underlying mechanisms of impaired working memory function related to insomnia and sleep loss.

Low Prefrontal GABA Levels Are Associated With Poor Cognitive Functions in Professional Boxers.

Cognitive dysfunction has long been recognized as a frequently observed symptom in individuals with repetitive mild traumatic brain injury (rmTBI) such as professional boxers. The exact neurobiological mechanisms underlying this cognitive deficit have not yet been identified, but it is agreed upon that the prefrontal cortex (PFC) is one of the most commonly affected brain regions in professional boxers. Noting the pivotal role of the two major brain metabolites in human cognitive functions, γ-aminobutyric acid (GABA) and glutamate/glutamine (Glx), we hypothesized that alterations in levels of GABA and Glx in the PFC would be prominent and may correlate with cognitive deficits in professional boxers. Twenty male professional boxers (Boxers) and 14 age-matched healthy males who had never experienced any TBI (CON) were recruited. Using a 3T magnetic resonance imaging (MRI) scanner, single-voxel proton magnetic resonance spectroscopy with Mescher-Garwood point-resolved spectroscopy (MEGA-PRESS) sequence was performed to evaluate the levels of GABA and Glx in the PFC. Cognitive function was assessed using the memory and attention domains from the Cambridge Neuropsychological Test Automated Battery. The Boxers showed lower GABA level in the PFC compared to the CON, while also showing lower performance in the attention and memory domains. There were no significant between-group differences in Glx levels. Furthermore, the GABA level correlated with memory performance in the Boxers, but not in attention performance. The current findings may suggest that alterations in GABA levels in the PFC may be a potential neurochemical correlate underlying memory dysfunction related to rmTBI.

Altered functional connectivity in the fear network of firefighters with repeated traumatic stress.

BACKGROUND: Firefighters are routinely exposed to various traumatic events and often experience a range of trauma-related symptoms. Although these repeated traumatic exposures rarely progress to the development of post-traumatic stress disorder, firefighters are still considered to be a vulnerable population with regard to trauma.AimsTo investigate how the human brain responds to or compensates for the repeated experience of traumatic stress. METHOD: We included 98 healthy firefighters with repeated traumatic experiences but without any diagnosis of mental illness and 98 non-firefighter healthy individuals without any history of trauma. Functional connectivity within the fear circuitry, which consists of the dorsal anterior cingulate cortex, insula, amygdala, hippocampus and ventromedial prefrontal cortex (vmPFC), was examined using resting-state functional magnetic resonance imaging. Trauma-related symptoms were evaluated using the Impact of Event Scale - Revised. RESULTS: The firefighter group had greater functional connectivity between the insula and several regions of the fear circuitry including the bilateral amygdalae, bilateral hippocampi and vmPFC as compared with healthy individuals. In the firefighter group, stronger insula-amygdala connectivity was associated with greater severity of trauma-related symptoms (ß = 0.36, P = 0.005), whereas higher insula-vmPFC connectivity was related to milder symptoms in response to repeated trauma (ß = -0.28, P = 0.01). CONCLUSIONS: The current findings suggest an active involvement of insular functional connectivity in response to repeated traumatic stress. Functional connectivity of the insula in relation to the amygdala and vmPFC may be potential pathways that underlie the risk for and resilience to repeated traumatic stress, respectively.Declaration of interestNone.

Alterations in structural rich-club connectivity of the precuneus are associated with depressive symptoms among individuals with subjective memory complaints.

The association between subjective memory complaints (SMCs) and depressive symptoms has been widely reported and both have been regarded as risk factors for dementia, such as Alzheimer's disease (AD). Although SMCs arise as early as in middle age, the exact neural correlates of comorbid depressive symptoms among individuals who are middle-aged and with SMCs have not yet been well investigated. Because rich-club organization of the brain plays a key role in the pathophysiology of various neuropsychiatric disorders, the investigation of rich club organization may provide insight regarding the neurobiological mechanisms of depressive symptoms in SMCs. In the current study, we compared the rich-club organization in the structural brain connectivity between individuals who have SMCs along with depressive symptoms (SMCD) and individuals with SMCs but without depressive symptoms (SMCO). A total of 53 individuals with SMCD and 91 individuals with SMCO participated in the study. For all participants, high-resolution, T1-weighted images and diffusion tensor images were obtained, and the network analysis was performed. Individuals with SMCD had lower connectivity strength between the precuneus and other rich-club nodes than those with SMCO, which was significant after adjusting for potential confounders. Our findings suggest that disruptions of rich-club connectivity strength of the precuenus are associated with depressive symptoms in middle-aged individuals with SMCs. Given that the precuneus is one of the commonly affected regions in the early stages of AD, our findings may imply that the concomitant depressive symptoms in middle-aged individuals with SMCs could reflect structural alterations related to AD.

Altered attentional control over the salience network in complex regional pain syndrome.

The degree and salience of pain have been known to be constantly monitored and modulated by the brain. In the case of maladaptive neural responses as reported in centralized pain conditions such as complex regional pain syndrome (CRPS), the perception of pain is amplified and remains elevated even without sustained peripheral pain inputs. Given that the attentional state of the brain greatly influences the perception and interpretation of pain, we investigated the role of the attention network and its dynamic interactions with other pain-related networks of the brain in CRPS. We examined alterations in the intra- and inter-network functional connectivities in 21 individuals with CRPS and 49 controls. CRPS-related reduction in intra-network functional connectivity was found in the attention network. Individuals with CRPS had greater inter-network connectivities between the attention and salience networks as compared with healthy controls. Furthermore, individuals within the CRPS group with high levels of pain catastrophizing showed greater inter-network connectivities between the attention and salience networks. Taken together, the current findings suggest that these altered connectivities may be potentially associated with the maladaptive pain coping as found in CRPS patients.

Brain structural changes in cynomolgus monkeys administered with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine: A longitudinal voxel-based morphometry and diffusion tensor imaging study.

In animal models of Parkinson's disease (PD), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is one of the most widely used agents that damages the nigrostriatal dopaminergic pathway. However, brain structural changes in response to MPTP remain unclear. This study aimed to investigate in vivo longitudinal changes in gray matter (GM) volume and white matter (WM) microstructure in primate models administered with MPTP. In six cynomolgus monkeys, high-resolution magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) scans were acquired 7 times over 32 weeks, and assessments of motor symptoms were conducted over 15 months, before and after the MPTP injection. Changes in GM volume and WM microstructure were estimated on a voxel-by-voxel basis. Mixed-effects regression models were used to examine the trajectories of these structural changes. GM volume initially increased after the MPTP injection and gradually decreased in the striatum, midbrain, and other dopaminergic areas. The cerebellar volume temporarily decreased and returned to its baseline level. The rate of midbrain volume increase was positively correlated with the increase rate of motor symptom severity (Spearman rho = 0.93, p = 0.008). Mean, axial, and radial diffusivity in the striatum and frontal areas demonstrated initial increases and subsequent decreases. The current multi-modal imaging study of MPTP-administered monkeys revealed widespread and dynamic structural changes not only in the nigrostriatal pathway but also in other cortical, subcortical, and cerebellar areas. Our findings may suggest the need to further investigate the roles of inflammatory reactions and glial activation as potential underlying mechanisms of these structural changes.

Natural Products from Single Plants as Sleep Aids: A Systematic Review.

Insufficient sleep, insomnia, and sleep-related problems are important health issues, as their overall prevalence accounts for about 30% of the general population. The aim of this study was to systematically review previous studies investigating the effects of orally administered single plant-derived extracts on sleep-related outcomes in humans. Data sources were PubMed, Google Scholar, and Cochrane Library. The data search was conducted in two steps: step 1, names of plants which have been studied as sleep aids in humans were searched and retrieved; and step 2, each ingredient listed in step 1 was then added into the search term. Only original articles or reviews were applicable to the scope of this review. Studies on human subjects, with or without sleep-related disorders, were included. Sleep-related disorders refer to not only insomnia or sleep behavior disorders but also diseases with sleep-related symptoms. Studies were considered eligible for this review when the plant extracts were administered orally. Outcome measures relevant to sleep quality, duration, or other sleep-related problems were included. Twenty-one plants were listed in the first step of the search as potential candidates for natural sleep aids. Seventy-nine articles using these single plant-derived natural products were included in the final review. Although valerian was most frequently studied, conflicting results were reported, possibly due to the various outcome measures of each study. Other plants were not as rigorously tested in human studies. There was limited evidence with inconclusive results regarding the effects of single plant-derived natural products on sleep, warranting further studies.

Firefighters, posttraumatic stress disorder, and barriers to treatment: Results from a nationwide total population survey.

Repeated exposure to traumatic experiences may put professional firefighters at increased risk of developing posttraumatic stress disorder (PTSD). To date, however, the rate of PTSD symptoms, unmet need for mental health treatment, and barriers to treatment have only been investigated in subsamples rather than the total population of firefighters. We conducted a nationwide, total population-based survey of all currently employed South Korean firefighters (n = 39,562). The overall response rate was 93.8% (n = 37,093), with 68.0% (n = 26,887) complete responses for all variables. The rate of current probable PTSD was estimated as 5.4%. Among those with current probable PTSD (n = 1,995), only a small proportion (9.7%) had received mental health treatment during the past month. For those who had not received treatment, perceived barriers of accessibility to treatment (29.3%) and concerns about potential stigma (33.8%) were reasons for not receiving treatment. Although those with higher PTSD symptom severity and functional impairment were more likely to seek treatment, greater symptom severity and functional impairment were most strongly associated with increased concerns about potential stigma. This nationwide study points to the need for new approaches to promote access to mental health treatment in professional firefighters.

Brain Perfusion Correlates of Apathy in Alzheimer's Disease.

BACKGROUND AND PURPOSE: Apathy is one of the most common neuropsychiatric symptoms in patients with Alzheimer's disease (AD). It may have adverse impacts on the progression of AD. However, its neurobiological underpinnings remain unclear. The objective of this study was to investigate differences in regional cerebral blood flow (rCBF) between AD patients with apathy and those without apathy. METHODS: Sixty-six apathetic AD patients and 66 AD patients without apathy completed Neuropsychiatric Inventory (NPI) and underwent technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPECT) scans. Voxel-wise differences in rCBF between the 2 groups were examined. Association between rCBF and levels of apathy in the apathetic group was also assessed. RESULTS: AD patients with apathy showed lower rCBF in the bilateral orbitofrontal cortex, left putamen, left nucleus accumbens, left thalamus, and bilateral insula than those without (all p<0.005). Mean perfusion across all significant clusters showed a negative linear correlation with NPI apathy score in AD patients with apathy (ß=-0.25; p=0.04). CONCLUSIONS: Hypoperfusion in the prefrontal, striatal, and insular areas may be neural correlates of apathy in AD patients.

Metabolic alterations in the anterior cingulate cortex and related cognitive deficits in late adolescent methamphetamine users.

The adolescent brain, with ongoing prefrontal maturation, may be more vulnerable to drug use-related neurotoxic changes as compared to the adult brain. We investigated whether the use of methamphetamine (MA), a highly addictive psychostimulant, during adolescence affect metabolic and cognitive functions of the anterior cingulate cortex (ACC). In adolescent MA users (n = 44) and healthy adolescents (n = 53), the levels of N-acetyl aspartate (NAA), a neuronal marker, were examined in the ACC using proton magnetic resonance spectroscopy. The Stroop color-word task was used to assess Stroop interference, which may reflect cognitive functions of behavior monitoring and response selection that are mediated by the ACC. Adolescent MA users had lower NAA levels in the ACC (t = -2.88, P = 0.005) and relatively higher interference scores (t = 2.03, P = 0.045) than healthy adolescents. Moreover, there were significant relationships between lower NAA levels in the ACC and worse interference scores in adolescent MA users (r = -0.61, P < 0.001). Interestingly, early onset of MA use, as compared to late onset, was related to both lower NAA levels in the ACC (t = -2.24, P = 0.03) as well as lower performance on interference measure of the Stroop color-word task (t = 2.25, P = 0.03). The current findings suggest that metabolic dysfunction in the ACC and its related cognitive impairment may play an important role in adolescent-onset addiction, particularly during early adolescence.

Diagnostic potential of multimodal neuroimaging in posttraumatic stress disorder.

Despite accumulating evidence of physiological abnormalities related to posttraumatic stress disorder (PTSD), the current diagnostic criteria for PTSD still rely on clinical interviews. In this study, we investigated the diagnostic potential of multimodal neuroimaging for identifying posttraumatic symptom trajectory after trauma exposure. Thirty trauma-exposed individuals and 29 trauma-unexposed healthy individuals were followed up over a 5-year period. Three waves of assessments using multimodal neuroimaging, including structural magnetic resonance imaging (MRI) and diffusion-weighted MRI, were performed. Based on previous findings that the structural features of the fear circuitry-related brain regions may dynamically change during recovery from the trauma, we employed a machine learning approach to determine whether local, connectivity, and network features of brain regions of the fear circuitry including the amygdala, orbitofrontal and ventromedial prefrontal cortex (OMPFC), hippocampus, insula, and thalamus could distinguish trauma-exposed individuals from trauma-unexposed individuals at each recovery stage. Significant improvement in PTSD symptoms was observed in 23%, 52%, and 88% of trauma-exposed individuals at 1.43, 2.68, and 3.91 years after the trauma, respectively. The structural features of the amygdala were found as major classifiers for discriminating trauma-exposed individuals from trauma-unexposed individuals at 1.43 years after the trauma, but these features were nearly normalized at later phases when most of the trauma-exposed individuals showed clinical improvement in PTSD symptoms. Additionally, the structural features of the OMPFC showed consistent predictive values throughout the recovery period. In conclusion, the current study provides a promising step forward in the development of a clinically applicable predictive model for diagnosing PTSD and predicting recovery from PTSD.

Psychometric Properties of the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) in Public First Responders.

Problematic alcohol consumption is prevalent among first responders because alcohol is commonly used to cope with occupational stress and frequent exposure to traumatic incidents, making them an at-risk population for alcohol use disorders (AUD). This study investigated the psychometric properties of the Korean version of the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) among public first responders. The Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders-IV-Text Revision (SCID), AUDIT-C, AUDIT, and CAGE were administered to 222 public first responders, who were recruited by convenience sampling. One-week test-retest reliability was evaluated in a subsample (n = 24). Receiver operating characteristic (ROC) curve analyses were conducted to evaluate the diagnostic accuracy and estimate the optimal cut-off scores for any AUD and alcohol dependence. Three different analytic criteria were utilized to calculate the cut-off scores. The AUDIT-C demonstrated good test-retest reliability (intraclass correlation coefficient for test-retest reliability = 0.91) and satisfactory convergent validity. The areas under the ROC curves for any AUD and alcohol dependence of the AUDIT-C were 0.87 and 0.93, respectively. For any AUD, all three criteria suggested a cut-off score of 7.5 (sensitivity = 81.8%, specificity = 79.8%), whereas for alcohol dependence, a cut-off score of 8.5 (sensitivity = 85.7%, specificity = 86.1%) was derived from two criteria. In conclusion, the AUDIT-C demonstrated good reliability and validity and proved to be a brief and effective screening test for AUD among first responders.

Recovery from Posttraumatic Stress Requires Dynamic and Sequential Shifts in Amygdalar Connectivities.

The neural mechanisms underlying the development and maintenance of posttraumatic stress disorder (PTSD) have long been studied. However, little is known about the neural correlates of the recovery process from PTSD. A 5-year longitudinal study was conducted to investigate the trajectory of structural connectivities of the amygdala in disaster survivors with PTSD. Thirty disaster survivors, who were diagnosed with PTSD, and 29 healthy individuals, who were not exposed to trauma, underwent three waves of assessments including neuroimaging scanning over a 5-year period from the time of the disaster at approximately 1.3-year intervals. All disaster survivors showed significant improvements in PTSD symptoms over time. Using diffusion tensor imaging analysis, a 5-year trajectory of amygdalar structural connectivities with key brain regions was assessed. The amygdala-insula connection was initially strengthened and then normalized during recovery, while the amygdala-prefrontal cortex (PFC) connection was at first unaffected, then strengthened, and eventually normalized. The lower tract strength of the amygdala-thalamus connection normalized during recovery, while that of amygdala-hippocampus connection remained low. The greater amygdala-PFC connectivity was associated with less PTSD symptom severity. The present longitudinal study revealed that recovery from PTSD parallels dynamic and sequential shifts in amygdalar connectivities with multiple brain regions, suggesting the expanded view of fear circuitry including the insula and thalamus, beyond the traditional model which primarily involves the amygdala, PFC, and hippocampus.

Prefrontal Cortical Thickness Deficit in Detoxified Alcohol-dependent Patients.

Alcohol dependence is a serious disorder that can be related with a number of potential health-related and social consequences. Cortical thickness measurements would provide important information on the cortical structural alterations in patients with alcohol dependence. Twenty-one patients with alcohol dependence and 22 healthy comparison subjects have been recruited and underwent high-resolution brain magnetic resonance (MR) imaging and clinical assessments. T1-weighted MR images were analyzed using the cortical thickness analysis program. Significantly thinner cortical thickness in patients with alcohol dependence than healthy comparison subjects was noted in the left superior frontal cortical region, correcting for multiple comparisons and adjusting with age and hemispheric average cortical thickness. There was a significant association between thickness in the cluster of the left superior frontal cortex and the duration of alcohol use. The prefrontal cortical region may particularly be vulnerable to chronic alcohol exposure. It is also possible that the pre-existing deficit in this region may have rendered individuals more susceptible to alcohol dependence.

Validation of the Korean version of the Connor-Davidson Resilience Scale-2 in firefighters and rescue workers.

OBJECTIVE: Resilience has been considered as a protective factor against stress. Evaluating resilience in firefighters and rescue workers, who are frequently exposed to traumatic events, is important and relevant. This study examined the psychometric properties of the Korean version of the Connor-Davidson Resilience Scale-2 (CD-RISC2). METHODS: Two-hundred twenty-two current professional firefighters and rescue workers were assessed by standardized, semi-structured clinical interviews and self-report questionnaires. Internal consistency, correlation with the CD-RISC, convergent validity, divergent validity, and predictive validity of posttraumatic stress disorder (PTSD) symptom severity were analyzed. RESULTS: The CD-RISC2 demonstrated good internal consistency (α=0.75), item-total correlation (r=0.89-0.90), and convergent and divergent validity. The total score of the CD-RISC2 showed significant correlations with the subtotal of the remaining 23 CD-RISC items (r=0.77, p<0.001) and with the score of each CD-RISC item (r=0.15-0.66, all p<0.05). The magnitude of the relationship between the number of traumatic experiences and PTSD symptom severity was greater in the low resilience group than in the high resilience group (p for interaction=0.002). The likelihood-ratio test confirmed that the model predicting PTSD symptom severity based on the CD-RISC2 total score was not improved by the inclusion of subtotal scores of the remaining 23 CD-RISC items (χ(2)=0.31, p=0.58). CONCLUSIONS: These results suggest that the CD-RISC2 would be a valuable tool in evaluating resilience quickly and efficiently in firefighters and rescue workers.