The relation of worry to prefrontal cortex volume in older adults with and without generalized anxiety disorder

Hippocampal subfield volume in older adults with and without mild cognitive impairment: Effects of worry and cognitive reappraisal

Studies have confirmed that anxiety, especially worry and rumination, are associated with increased risk for cognitive decline, including Alzheimer's disease and related dementias (ADRD). Hippocampal atrophy is a hallmark of ADRD. We investigated the association between hippocampus and its subfield volumes and late-life global anxiety, worry, and rumination, and emotion regulation strategies. We recruited 110 participants with varying worry severity who underwent magnetic resonance imaging and clinical interviews. We conducted cross-sectional regression analysis between each subfield and anxiety, worry, rumination, reappraisal, and suppression while adjusting for age, sex, race, education, cumulative illness burden, stress, neuroticism, and intracranial volume. We imputed missing data and corrected for multiple comparisons across regions. Greater worry was associated with smaller subiculum volume, whereas greater use of reappraisal was associated with larger subiculum and CA1 volume. Greater worry may be detrimental to the hippocampus and to subfields involved in early ADRD pathology. Use of reappraisal appears protective of hippocampal structure. Worry and reappraisal may be modifiable targets for ADRD prevention.

Transdiagnostic symptom of depression and anxiety associated with reduced gray matter volume in prefrontal cortex

Dimensional models of psychopathology may provide insight into mechanisms underlying comorbid depression and anxiety and improve specificity and sensitivity of neuroanatomical findings. The present study is the first to examine neural structure alterations using the empirically derived Tri-level Model. Depression and anxiety symptoms of 269 young adults were assessed using the Tri-level Model dimensions: General Distress (transdiagnostic depression and anxiety symptoms), Anhedonia-Apprehension (relatively specific depression symptoms), and Fears (specific anxiety symptoms). Using structural MRI, gray matter volumes were extracted for emotion generation (amygdala, nucleus accumbens) and regulation (orbitofrontal, ventrolateral, and dorsolateral prefrontal cortex) regions, often implicated in depression and anxiety. Each Tri-level symptom was regressed onto each region of interest, separately, adjusting for relevant covariates. General Distress was significantly associated with smaller gray matter volumes in bilateral orbitofrontal cortex and ventrolateral prefrontal cortex, independent of Anhedonia-Apprehension and Fears symptom dimensions. These results suggests that prefrontal alterations are associated with transdiagnostic dysphoric mood common across depression and anxiety, rather than unique symptoms of these disorders. Additionally, no regions of interest were associated with Anhedonia-Apprehension or Fears, highlighting the importance of studying transdiagnostic features of depression and anxiety. This has implications for understanding mechanisms of and interventions for depression and anxiety.

Examining the relationship between anxiety and regional brain volumes in the National Alzheimer's Coordinating Center uniform, imaging, and biomarker datasets

Anxiety has been associated with a greater risk of Alzheimer's disease (AD). Existing research has identified structural differences in regional brain tissue in participants with anxiety, but results have been inconsistent. We sought to determine the association between anxiety and regional brain volumes, and the moderation effect of APOE ε4. Using data from participants in the National Alzheimer's Coordinating Center (NACC) Uniform Data Set, with complete imaging (MRI) and biomarker data (n = 1533), multiple linear regression estimated the adjusted effect of anxiety on 30 structural MRI regions. The moderation effect of APOE ε4 on the relation between structural MRI regions and anxiety was assessed as was the moderation effect of cognitive status. False discovery rate was used to adjust for multiple comparisons. After controlling for intracranial volume, age, sex, years of education, race, Hispanic ethnicity, and cognitive status, seven MRI regions demonstrated lower volumes among participants with anxiety: total cerebrum gray matter volume, right hippocampus volume, hippocampal volume (total), right and left frontal lobe cortical gray matter volume, and right and total temporal lobe cortical gray matter volume. Findings suggest that anxiety is associated with significant atrophy in multiple brain regions, with corresponding ventricular enlargement. Future research should investigate if anxiety-related changes to brain morphology contribute to greater AD risk.

White Noise-Is Anxiety in Late-Life Associated With White Matter Hyperintensity Burden?

OBJECTIVE

We investigated the relationship between anxiety phenotypes (global anxiety, worry, and rumination) and white matter hyperintensities (WMH), with special consideration for the roles of age and executive function (EF). Our hypotheses were 1) anxiety phenotypes would be associated with WMH and 2) EF would moderate this relationship.

DESIGN

Cross-sectional.

SETTING

Participants were recruited from the local community (Pittsburgh, PA).

PARTICIPANTS

We recruited 110 older adults (age ≥ 50) with varying worry severity and clinical comorbidity.

INTERVENTIONS

Not applicable.

MEASUREMENTS

Demographics (age, sex, race, education), clinical measures (cumulative illness burden, global anxiety, worry, and rumination), EF, and WMH quantified with magnetic resonance imaging.

RESULTS

Lower global anxiety and worry severity were significantly correlated with higher WMH volume, though the global anxiety relationship was not significant after controlling for age. Rumination as not associated with WMH burden. EF was not correlated with either global anxiety, worry, rumination, or WMH. However, in those with advanced age and/or greater WMH burden, there was an association between worry and EF as well as EF and WMH.

CONCLUSION

Longitudinal studies are needed in order to clarify the complex interactions between anxiety phenotypes, WMH, and EF.

Mindfulness attenuates the impact of worry on late-life cognitive function

Objectives: Worry has been shown to have a negative impact on many aspects of neurocognitive performance. Interestingly, research indicates mindfulness both improves aspects of cognitive ability and reduces worry symptoms. Yet, the impact of mindfulness on the relationship between worry and cognition has yet to be explored. Based on research discussed herein, we hypothesize that those with higher levels of dispositional mindfulness will have better cognitive performance than those with lower levels of dispositional mindfulness, regardless of worry level. The present study investigated the potential moderating influence of mindfulness on the relationship between worry and cognitive performance.Methods: The sample included 113 older veterans who were screened at the VA Palo Alto Health Care System in Palo Alto, CA. Cognitive domains of interest included learning and memory, processing speed, attention, working memory, and executive function. Mindfulness was assessed with the Five Facet Mindfulness Questionnaire (FFMQ), and worry symptoms were assessed using the Penn State Worry Questionnaire (PSWQ). Hypotheses were tested with multiple regression analyses using the Hayes (2003) PROCESS macro.Results: Contrary to what was hypothesized, only mindful awareness significantly moderated the relationship between worry and processing speed.Conclusion: This finding has important implications for introducing mindfulness techniques into older adults' routines to decrease worry and mitigate its negative effects on processing speed.

Associations between anxiety, centromedial amygdala volume, and complex verbal fluency in middle-aged to older adults

Symptoms of anxiety are related to decreases in cognitive performance in middle-aged to older adults (i.e., ages 50 and older; MOA). Verbal fluency (VF), assessed with the Delis-Kaplan Executive Function System (D-KEFS) Category Switching (VF-CS) task, captures elements of executive function such as semantic memory, response initiation and inhibition, and cognitive flexibility. The present study examined the link between anxiety symptoms and VF-CS to better understand how this association affects such executive functions in MOA. We hypothesized that higher subclinical Beck Anxiety Inventory (BAI) scores would be associated with lower VF-CS. To further investigate the underlying neurobiological basis of an expected inverse relationship, total amygdala volume, centromedial amygdala (CMA) volume, and basolateral amygdala (BLA) volume were examined as they related to VF-CS scores on the D-KEFS. Based on extant research on connectivity and functioning between the CMA and BLA, we hypothesized that larger BLA volumes would be associated with lower anxiety scores and exhibit positive relationships with VF-CS. A sample of 63 MOA were recruited from the Providence, Rhode Island area as a part of a parent study on cardiovascular diseases. Participants completed self-report measures about physical and emotional health, a neuropsychological assessment, and a magnetic resonance imaging scan (MRI). Multiple hierarchical regressions were performed to examine relationships between variables of interest. Contrary to hypotheses, no significant relationship emerged between VF-CS and BAI scores, and BLA volume was not associated with either BAI scores or VF-CS. However, a significant positive relationship was observed between CMA volume and VF-CS. The significant relationship found between CMA and VF-CS may reflect the upward slope of the quadratic relationship between arousal and cognitive performance on the Yerkes-Dodson curve. These findings newly implicate CMA volume specifically as a possible neuromarker linking emotional arousal and cognitive performance in MOA.

The relationship between chronic PTSD, cortical volumetry and white matter microstructure among Australian combat veterans

BACKGROUND

Posttraumatic stress disorder (PTSD) has been associated with volumetric and white matter microstructural changes among general and veteran populations. However, regions implicated have greatly varied and often conflict between studies, potentially due to confounding comorbidities within samples. This study compared grey matter volume and white matter microstructure among Australian combat veterans with and without a lifetime diagnosis of PTSD, in a homogenous sample assessed for known confounding comorbidities.

METHODS

Sixty-eight male trauma-exposed veterans (16 PTSD-diagnosed; mean age 69 years) completed a battery of psychometric assessments and underwent magnetic resonance and diffusion tensor imaging. Analyses included tract-based spatial statistics, voxel-wise analyses, diffusion connectome-based group-wise analysis, and volumetric analysis.

RESULTS

Significantly smaller grey matter volumes were observed in the left prefrontal cortex (P = 0.026), bilateral middle frontal gyrus (P = 0.021), and left anterior insula (P = 0.048) in the PTSD group compared to controls. Significant negative correlations were found between PTSD symptom severity and fractional anisotropy values in the left corticospinal tract (R² = 0.34, P = 0.024) and left inferior cerebellar peduncle (R² = 0.62, P = 0.016). No connectome-based differences in white matter properties were observed.

CONCLUSIONS

Findings from this study reinforce reports of white matter alterations, as indicated by reduced fractional anisotropy values, in relation to PTSD symptom severity, as well as patterns of reduced volume in the prefrontal cortex. These results contribute to the developing profile of neuroanatomical differences uniquely attributable to veterans who suffer from chronic PTSD.

Heterogenous Subtypes of Late-Life Depression and Their Cognitive Patterns: A Latent Class Analysis

Background

Late-life depression (LLD), characterized by cognitive deficits, is considered heterogeneous across individuals. Previous studies have identified subtypes with diverse symptom profiles, but their cognitive patterns are unknown. This study aimed to investigate the subtypes of LLD and the cognitive profile of each group.

Methods

In total, 109 depressed older adults were enrolled. We performed latent class analysis using Geriatric Depression Scale items as indicators to generate latent classes. We compared the sociodemographic and clinical characteristics with cognitive functions between groups and conducted regression analysis to investigate the association between class membership and variables with significant differences.

Results

Two classes were identified: the "pessimistic" group was characterized by pessimistic thoughts and the "worried" group with a relatively high prevalence of worry symptoms. The two groups did not differ in sociodemographic characteristics. The "pessimistic" group showed a higher rate of past history of depression and lower age of onset. The "worried" group had more physical comorbidities and a higher rate of past history of anxiety. The "pessimistic" group was more impaired in general cognitive function, executive function, information processing speed, and attention. Lower general and executive functions were associated with the membership in the "pessimistic" group.

Conclusions

Subjects with pessimistic symptoms and subjects with a propensity to worry may form two distinct subtypes of late-life depression with different cognitive profiles. Further, the cognitive evaluation of subjects with pessimistic symptoms is of utmost importance.

Association between cortical thickness and anxiety measures: A scoping review

Cortical thickness has been increasingly studied in the context of structural-brain-behavior associations, such as anxiety; however, the literature is scattered across methods and research fields. This scoping review aims to summarize the available data concerning the association between cortical thickness and anxiety-related measures and identify the current research gaps. Searches were conducted in PubMed, PsycINFO/PsycARTICLES, Web of Science, OpenGrey and Networked Digital Library of Theses and Dissertations, and reference lists of key studies. Two researchers independently screened the abstracts and full-text reports according to the eligibility criteria, as well as extracted and charted the data. Quantitative and descriptive syntheses were conducted. The included publications (n = 18) reported cross-sectional studies, and 17 used surface-based approaches to estimate cortical thickness. Differences in regional cortical thickness were found to be associated with different anxiety-related measures/processes. Brain regions of interest include the medial orbitofrontal cortex, the ventromedial prefrontal cortex, the insula, the temporo-parietal areas, and the anterior cingulate cortex. However, caution should be warranted when interpreting the available results, as there is high variability in the field across anxiety-related measures, distinctive anxiety disorders, and data processing conditions and analysis. More research into this association is needed, to replicate and clarify existing findings.

The neuroanatomical correlates of repetitive negative thinking: A systematic review

Repetitive negative thinking (RNT) is a cognitive process characterised by intrusive, repetitive, and difficult-to-disengage-from negative thoughts. Heightened RNT levels are prevalent across clinical disorders and have been associated with ill-health (e.g. cardiovascular disease), even at lower, non-clinical levels. Identifying the neuroanatomical correlates of RNT could help characterise structural alterations that transcend diagnostic boundaries and further understanding of the pathogenesis of clinical disorders. We therefore conducted a systematic review to investigate associations between RNT and brain morphology. Following title/abstract and full-text screening, 24 studies were included. We found evidence that RNT severity is associated with grey and white matter volumes/microstructure, particularly in the dorsolateral prefrontal cortex, anterior cingulate cortex and superior longitudinal fasciculus, regions heavily implicated in cognitive control, and emotional processing and regulation. However, inconsistent associations, potentially due to the heterogeneity of included studies (e.g. methodological differences, type of RNT assessed), preclude specific conclusions being reached regarding any one region's association with RNT. Further, given the defuse nature of thoughts, it may be that RNT is associated with distributed brain regions operating within large-scale networks, rather than with a single structure. High quality longitudinal studies, investigating structural networks, are required to confirm the neuroanatomical basis of RNT and elucidate the direction of relationships.

Preexisting conditions in older adults with mild traumatic brain injuries

OBJECTIVE

This study examined the prevalence of preexisting conditions that could affect premorbid brain health, cognition, and functional independence among older adults with mild traumatic brain injury (MTBI), and the relationship between preexisting conditions, injury characteristics, and emergency department (ED) discharge location (home versus continued care).

METHODS

Older adults (N = 1,427; 55-104 years-old; 47.4% men) who underwent head computed tomography (CT) after acute head trauma were recruited from the ED. Researchers documented preexisting medical conditions retrospectively from hospital records.

RESULTS

Multiple preexisting conditions increased in frequency with greater age, including circulatory and nervous system diseases and preexisting abnormalities on head CT. Psychiatric and substance use disorders (SUDs) decreased in frequency with greater age. Among participants with uncomplicated MTBI and GCS = 15, preexisting nervous system diseases and preexisting CT abnormalities were associated with higher odds of continued care for all participants, whereas psychiatric disorders and SUDs were only associated with higher odds of continued care among participants <70 years-old. Preexisting circulatory diseases, loss of consciousness, and amnesia were unassociated with discharge location.

CONCLUSIONS

Preexisting medical conditions that could affect brain and cognitive health occur commonly among older adults who sustain MTBIs. These conditions can confound research examining post-injury outcomes within this age group.

Pathological Worry is Related to Poor Long-Term Pharmacological Treatment Response in Patients With Panic Disorder

OBJECTIVE

Several predictors of unfavorable pharmacological treatment response (PTR) in panic disorder (PD) patients have been suggested, such as the duration of the illness, presence of agoraphobia, depression, being a woman, and early trauma. This study aimed to examine whether pathological worry is associated with PTR in PD patients.

METHODS

This study included 335 PD patients and 418 healthy controls (HCs). The Penn State Worry Questionnaire (PSWQ), the Early Trauma Inventory Self Report-Short Form (ETISR-SF), Beck Depression Inventory (BDI), Panic Disorder Severity Scale (PDSS), and Anxiety Sensitivity Inventory-Revised (ASI-R) were administered. We measured the PTR at 8 weeks and 6 months. Student t-test, chisquare tests, Pearson's correlation analyses, and binary logistic regression model were used.

RESULTS

Our results showed that the total scores of the PSWQ correlated with the ETISR-SF, BDI, and ASI-R were significantly higher in patients with PD compared with HCs. The PSWQ and BDI could predict unfavorable PTR at 6 months in PD patients.

CONCLUSION

This is the first study to demonstrate that pathological worry may contribute to poor long-term PTR in PD patients. Therefore, our research suggests that clinicians must be aware of worry to optimize PTR for PD patients.

Heart Rate Variability Moderates the Association Between Beliefs About Worry and Generalized Anxiety Disorder Symptoms

Paradoxically, some individuals who experience pathological worry also have good capacity for top-down control over their thoughts. Why such individuals would nevertheless worry excessively remains unclear. One explanation is suggested by research showing that those experiencing pathological worry are set apart from healthy controls by their beliefs that worry has utility and that effective worrying requires them to consider all possibilities before terminating a worry bout. This suggests that worriers with good capacity for cognitive control may engage in prolonged worry because they believe it is adaptive to do so. In a sample of 109 college students, among whom individuals reporting pathological worry were overrepresented, we tested this hypothesis using an objective index of top-down control capacity (i.e., resting vagally mediated heart rate variability [vmHRV]) and self-report measures of beliefs about worry and generalized anxiety disorder (GAD) symptom severity/status. As predicted, GAD symptom severity and vmHRV interacted to predict beliefs about worry. Specifically, high GAD symptoms were most strongly associated with beliefs that worry has utility at higher levels of vmHRV. Furthermore, this pattern was mostly a function of the belief that worry serves to distract the worrier from more emotional things. Similarly, high GAD symptoms were most strongly associated with endorsement of an ‘as many as can’ (AMAC) problem-solving rule when vmHRV was high. From the opposite perspective, both worry utility beliefs and AMAC rule endorsement were associated with the highest GAD symptom severity at higher levels of vmHRV. This was also true for the belief that worry distracts from more emotional things predicting analog GAD status. These results suggest that worriers who have higher levels of top-down control capacity may initiate and persist in worry, at least initially, because they value it. However, why they nevertheless rate their worry as excessive and uncontrollable is an important question for future research.

Neurocognitive predictors of long-term outcome in CBT for late life generalized anxiety disorder

Generalized anxiety disorder (GAD) is currently recognized as one of the most common and impairing psychiatric conditions in adults age 65 and over. Although clinical trials have indicated that cognitive behavior therapy (CBT) is efficacious, it has not shown consistent superiority over other types of psychosocial interventions. This study sought to identify baseline neurocognitive predictors of posttreatment and distal follow-up outcome of CBT for late life GAD, which could be used to estimate response and optimize the intervention. First, results indicated that CBT was effective in reducing worry and other symptoms immediately following and 18 months after the last full session of treatment. Regression models of baseline predictors included pretreatment worry scores, the number of comorbid conditions, hypertension, and scores on a working memory task or hippocampal volumes as predictors of endpoint PSWQ scores. Results replicated known baseline predictors of outcome at both assessment points, and identified one new predictor of distal outcome. Clinicians may benefit from including working memory tasks as assessment and augmentation tools in treating older GAD patients.

Systematic review and meta-analyses of neural structural and functional differences in generalized anxiety disorder and healthy controls using magnetic resonance imaging

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PFC-amygdala FC is altered in GAD, indicating top-down processing deficits.

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GAD had reduced activity for emotion regulation and working memory in the culmen.

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Salience, default, and central executive nodes have altered structure and function.

Objective

To compare structure, functional connectivity (FC) and task-based neural differences in subjects with generalized anxiety disorder (GAD) compared to healthy controls (HC).

Methods

The Embase, Ovid Medline, PsycINFO, Scopus, and Web of Science databases were searched from inception until March 12, 2018. Two reviewers independently screened titles, abstracts, and full-text articles. Data were extracted from records directly contrasting GAD and HC that included structure (connectivity and local indices such as volume, etc.), FC, or task-based magnetic resonance imaging data. Meta-analyses were conducted, as applicable, using AES-SDM software.

Results

The literature search produced 4,645 total records, of which 85 met the inclusion criteria for the systematic review. Records included structural (n = 35), FC (n = 33), and task-based (n = 42) findings. Meta-analyses were conducted on voxel-based morphometry and task-based results.

Discussion

The systematic review confirms and extends findings from previous reviews. Although few whole-brain resting state studies were conducted, key nodes of resting state networks have altered physiology: the hippocampus (default network), ACC and amygdala (salience network), have reduced volume, and the dlPFC (central executive network) and ACC have reduced FC with the amygdala in GAD. Nodes in the sensorimotor network are also altered with greater pre- and postcentral volume, reduced supplementary motor area volume, and reduced FC in anterior and increased FC in posterior cerebellum.

Conclusions

Despite limitations due to sample size, the meta-analyses highly agree with the systematic review and provide evidence of widely distributed neural differences in subjects with GAD, compared to HC. Further research optimized for meta-analyses would greatly improve large-scale comparisons.

Individualized prediction of dispositional worry using white matter connectivity

BACKGROUND

Excessive worry is a defining feature of generalized anxiety disorder and is present in a wide range of other psychiatric conditions. Therefore, individualized predictions of worry propensity could be highly relevant in clinical practice, with respect to the assessment of worry symptom severity at the individual level.

METHODS

We applied a multivariate machine learning approach to predict dispositional worry based on microstructural integrity of white matter (WM) tracts.

RESULTS

We demonstrated that the machine learning model was able to decode individual dispositional worry scores from microstructural properties in widely distributed WM tracts (mean absolute error = 10.46, p < 0.001; root mean squared error = 12.82, p < 0.001; prediction R2 = 0.17, p < 0.001). WM tracts that contributed to worry prediction included the posterior limb of internal capsule, anterior corona radiate, and cerebral peduncle, as well as the corticolimbic pathways (e.g. uncinate fasciculus, cingulum, and fornix) already known to be critical for emotion processing and regulation.

CONCLUSIONS

The current work thus elucidates potential neuromarkers for clinical assessment of worry symptoms across a wide range of psychiatric disorders. In addition, the identification of widely distributed pathways underlying worry propensity serves to better improve the understanding of the neurobiological mechanisms associated with worry.

Structural and functional neuroimaging studies in generalized anxiety disorder: a systematic review

OBJECTIVES

Brain imaging studies carried out in patients suffering from generalized anxiety disorder (GAD) have contributed to better characterize the pathophysiological mechanisms underlying this disorder. The present study reviews the available functional and structural brain imaging evidence on GAD, and suggests further strategies for investigations in this field.

METHODS

A systematic literature review was performed in PubMed, PsycINFO, and Google Scholar, aiming to identify original research evaluating GAD patients with the use of structural and functional magnetic resonance imaging as well as diffusion tensor imaging.

RESULTS

The available studies have shown impairments in ventrolateral and dorsolateral prefrontal cortex, anterior cingulate, posterior parietal regions, and amygdala in both pediatric and adult GAD patients, mostly in the right hemisphere. However, the literature is often tentative, given that most studies have employed small samples and included patients with comorbidities or in current use of various medications. Finally, different methodological aspects, such as the type of imaging equipment used, also complicate the generalizability of the findings.

CONCLUSIONS

Longitudinal neuroimaging studies with larger samples of both juvenile and adult GAD patients, as well as at risk individuals and unaffected relatives, should be carried out in order to shed light on the specific biological signature of GAD.

Reduced cortical thickness and increased gyrification in generalized anxiety disorder: a 3 T MRI study

BACKGROUND

Although the study of the neuroanatomical correlates of generalized anxiety disorder (GAD) is gaining increasing interest, up to now the cortical anatomy of GAD patients has been poorly investigated and still no data on cortical gyrification are available. The aim of the present study is to quantitatively examine the cortical morphology in patients with GAD compared with healthy controls (HC) using magnetic resonance imaging (MRI). To the best of our knowledge, this is the first study analyzing the gyrification patterns in GAD.

METHODS

A total of 31 GAD patients and 31 HC underwent 3 T structural MRI. For each subject, cortical surface area (CSA), cortical thickness (CT), gray matter volume (GMV), and local gyrification index (LGI) were estimated in 19 regions of interest using the Freesurfer software. These parameters were then compared between the two groups using General Linear Model designs.

RESULTS

Compared with HC, GAD patients showed: (1) reduced CT in right caudal middle frontal gyrus (p < 0.05, Bonferroni corrected), (2) hyper-gyrification in right fusiform, inferior temporal, superior parietal and supramarginal gyri and in left supramarginal and superior frontal gyri (p < 0.05, Bonferroni corrected). No significant alterations in CSA and GMV were observed.

CONCLUSIONS

Our findings support the hypothesis of a neuroanatomical basis for GAD, highlighting a possible key role of the right hemisphere. The alterations of CT and gyrification in GAD suggest a neurodevelopmental origin of the disorder. Further studies on GAD are needed to understand the evolution of the cerebral morphology with age and during the clinical course of the illness.

Brain-heart interaction in perseverative cognition

The move from the concept of homeostasis to that of allostasis has led reactivity stress research to widen the object of its investigation: from the brief physiological response that occurs when one is facing a stressor to what happens when one is anticipating or recovering from a stressor. A paradigmatic example is represented by perseverative cognition, during which human beings react "as if" they were constantly facing a concrete stressor. The core idea behind this review is that the cognitive inflexibility that characterizes perseverative cognition is reflected in both our body (by increased autonomic nervous system rigidity assessed by heart rate variability; HRV) and our brain (by reduced prefrontal-amygdala functional connectivity). This is a review of studies conducted in different settings (laboratory, daily life), populations (healthy, major depression, generalized anxiety), location (United States, Europe), and age groups (children, adults) that consistently replicated the association between autonomic, subjective, and behavioral measures of cognitive inflexibility during perseverative cognition. Moreover, compelling neuroimaging data suggest that HRV reduction from pre- to post-induction of perseverative cognition is associated with both structural and functional brain abnormalities reflecting impaired prefrontal inhibitory control over subcortical structures (e.g., diminished prefrontal-amygdala functional connectivity). The integration of neuroscience techniques with clinical autonomic research has advanced our understanding of the neurobiology of brain-heart interaction during perseverative cognition, potentially yielding to more effective treatment packages. This is clinically relevant if one considers that perseverative cognition is a pervasive transdiagnostic factor that carries prognostic risk for both psychological and somatic health.

Advances and Barriers for Clinical Neuroimaging in Late-Life Mood and Anxiety Disorders

PURPOSE OF REVIEW

Mood and anxiety disorders are very commonly experienced by older adults and are becoming a growing concern due to the rapidly aging global population. Recent advances in neuroimaging may help in improving outcomes in late-life mood and anxiety disorders. The elucidation of mechanisms contributing to late-life mental health disorders may ultimately lead to the identification of novel therapeutic interventions. Alternatively, clinically validated imaging biomarkers may allow for the prediction of treatment response and identification of better therapeutic approaches in late-life mood and anxiety disorders.

RECENT FINDINGS

In community samples, late-life depression and late-life generalized anxiety disorder occur up to 38 and 15%, respectively, while late-life bipolar disorder is less common and occur in approximately 0.5% of the population. There are significant challenges in treating and improving outcome in late-life mood and anxiety disorders. Time to treatment response and treatment resistance are increased in older adults. Novel neuroimaging techniques have the potential to improve diagnostic and therapeutic outcome in late-life mood and anxiety disorders either through "personalized pharmacotherapy" or through identifying dysfunction regions/networks to be subsequently used for direct interventions such as transcranial magnetic stimulation. This review will provide an overview of recent literature that substantiates the potential role of neuroimaging in clinical practice, as well as the barriers that must be overcome prior to clinical translation.

Brain structural changes in late-life generalized anxiety disorder

Late-life Generalized Anxiety Disorder (GAD) is relatively understudied and the underlying structural and functional neuroanatomy has received little attention. In this study, we compare the brain structural characteristics in white and gray matter in 31 non-anxious older adults and 28 late-life GAD participants. Gray matter indices (cortical thickness and volume) were measured using FreeSurfer parcellation and segmentation, and mean diffusivity was obtained through Diffusion Tensor Imaging (DTI). We assessed both macroscopic white matter changes [using white matter hyperintensity (WMH) burden] and microscopic white matter integrity [using fractional anisotropy (FA)]. No differences in macro- or microscopic white matter integrity were found between GAD and non-anxious controls (HC). GAD participants had lower cortical thickness in the orbitofrontal cortex (OFC), inferior frontal gyrus, and pregenual anterior cingulate cortex (ACC). Higher worry severity was associated with gray matter changes in OFC, ACC and the putamen. The results did not survive the multiple comparison correction, but the effect sizes indicate a moderate effect. The study suggests that late-life GAD is associated with gray matter changes in areas involved in emotion regulation, more so than with white matter changes. We conclude that anxiety-related chronic hypercortisolemia may have a dissociative effect on gray and white matter integrity.

Prefrontal-limbic connectivity during worry in older adults with generalized anxiety disorder

OBJECTIVES

Although generalized anxiety disorder (GAD) is one of the most prevalent anxiety disorders in older adults, very little is known about the neurobiology of worry, the hallmark symptom of GAD in adults over the age of 60. This study investigated the neurobiology and neural circuitry of worry in older GAD patients and controls.

METHOD

Twenty older GAD patients and 16 age-matched controls (mean age = 67.88) were compared on clinical measures and neural activity during worry using functional magnetic resonance imaging.

RESULTS

As expected, worry elicited activation in frontal regions, amygdala, and insula within the GAD group, with a similar but less prominent frontal pattern was observed in controls. Effective connectivity analyses revealed a positive directional circuit in the GAD group extending from ventromedial through dorsolateral prefrontal cortices, converging on the amygdala. A less complex circuit was observed in controls with only dorsolateral prefrontal regions converging on the amygdala; however, a separate circuit passing through the orbitofrontal cortex converged on the insula.

CONCLUSION

Results elucidate a different neurobiology of pathological versus normal worry in later life. A limited resource model is implicated wherein worry in GAD competes for the same neural resources (e.g. prefrontal cortical areas) that are involved in the adaptive regulation of emotion through cognitive and behavioral strategies.

Altered brain network topology in left-behind children: A resting-state functional magnetic resonance imaging study

Whether a lack of direct parental care affects brain function in children is an important question, particularly in developing countries where hundreds of millions of children are left behind when their parents migrate for economic or political reasons. In this study, we investigated changes in the topological architectures of brain functional networks in left-behind children (LBC). Resting-state functional magnetic resonance imaging data were obtained from 26 LBC and 21 children living within their nuclear family (non-LBC). LBC showed a significant increase in the normalized characteristic path length (λ), suggesting a decrease in efficiency in information access, and altered nodal centralities in the fronto-limbic regions and motor and sensory systems. Moreover, a decreased nodal degree and the nodal betweenness of the right rectus gyrus were positively correlated with annual family income. The present study provides the first empirical evidence that suggests that a lack of direct parental care could affect brain functional development in children, particularly involving emotional networks.

Emotion Reactivity and Cerebrovascular Burden in Late-Life GAD: A Neuroimaging Study

OBJECTIVE

Generalized anxiety disorder (GAD) in older adults is associated with persistent deficits in emotion reactivity (ER) and regulation, yet the neural basis of these deficits has not been explored. This study focuses on the neural basis of ER deficits in late-life GAD and the association with cerebrovascular burden.

METHODS

Twenty elderly nonanxious participants and 17 late-life GAD participants were included. The faces-shapes functional magnetic resonance imaging task was used to assess ER; the Hamilton Anxiety Rating Scale and the Penn State Worry Questionnaire to measure global anxiety and worry, respectively; linear regression models to examine the association between ER and global anxiety severity and between ER and worry severity; and mediation analysis to explore the effect of ER on the relationship between global anxiety/worry severity and cerebrovascular burden.

RESULTS

A positive association was found between ER and global anxiety in the left parahippocampus, left and right precuneus, and right superior occipital gyrus. A negative association was found between ER and worry severity in the left and right precuneus. The association between cerebrovascular burden and anxiety/worry severity was indirectly mediated by increased ER in limbic and paralimbic areas and by decreased ER in prefrontal regulatory regions.

CONCLUSION

These results indicate that ER is associated with different neural activation patterns for worry and global anxiety and that ER-related functional connectivity indirectly mediates the relationship between cerebrovascular burden and late-life GAD. This latter result supports a yet-unexplored cerebrovascular pathway involved in the pathophysiology of late-life anxiety.

The interplay of trait worry and trait anxiety in determining episodic retrieval: The role of cognitive control

Worrying is a key concept in describing the complex relationship between anxiety and cognitive control. On the one hand, cognitive control processes might underlie the specific tendency to engage in worrying (i.e., trait worry), conceptualized as a future-oriented mental problem-solving activity. On the other hand, the general tendency to experience the signs and symptoms of anxiety (i.e., trait anxiety) is suggested to impair cognitive control because worrisome thoughts interfere with task-relevant processing. Based on these opposing tendencies, we predicted that the effect of the two related constructs, trait anxiety and trait worry, might cancel out one another. In statistics, such instances have been termed suppressor situations. In four experiments, we found evidence for such a suppressor situation: When their shared variance was controlled, trait worry was positively whereas trait anxiety was negatively related to performance in a memory task requiring strategic, effortful retrieval. We also showed that these opposing effects are related to temporal context reinstatement. Our results suggest that trait worry and trait anxiety possess unique sources of variance, which differently relate to performance in memory tasks requiring cognitive control.

Neurostructural abnormalities associated with axes of emotion dysregulation in generalized anxiety

BACKGROUND

Despite the high prevalence of generalized anxiety disorder (GAD) and its negative impact on society, its neurobiology remains obscure. This study characterizes the neurostructural abnormalities associated with key symptoms of GAD, focusing on indicators of impaired emotion regulation (excessive worry, poor concentration, low mindfulness, and physiological arousal).

METHODS

These domains were assessed in 19 (16 women) GAD patients and 19 healthy controls matched for age and gender, using questionnaires and a low demand behavioral task performed before and after an induction of perseverative cognition (i.e. worry and rumination). Continuous pulse oximetry was used to measure autonomic physiology (heart rate variability; HRV). Observed cognitive and physiological changes in response to the induction provided quantifiable data on emotional regulatory capacity. Participants underwent structural magnetic resonance imaging; voxel-based morphometry was used to quantify the relationship between gray matter volume and psychological and physiological measures.

RESULTS

Overall, GAD patients had lower gray matter volume than controls within supramarginal, precentral, and postcentral gyrus bilaterally. Across the GAD group, increased right amygdala volume was associated with prolonged reaction times on the tracking task (indicating increased attentional impairment following the induction) and lower scores on the 'Act with awareness' subscale of the Five Facets Mindfulness Questionnaire. Moreover in GAD, medial frontal cortical gray matter volume correlated positively with the 'Non-react mindfulness' facet. Lastly, smaller volumes of bilateral insula, bilateral opercular cortex, right supramarginal and precentral gyri, anterior cingulate and paracingulate cortex predicted the magnitude of autonomic change following the induction (i.e. a greater decrease in HRV).

CONCLUSIONS

Results distinguish neural structures associated with impaired capacity for cognitive, attentional and physiological disengagement from worry, suggesting that aberrant competition between these levels of emotional regulation is intrinsic to symptom expression in GAD.

Gray matter characteristics associated with trait anxiety in older adults are moderated by depression

BACKGROUND

Structural gray matter characteristics of anxiety remain unclear. The aim of this study was to assess the influence of current depressive symptoms and history of depression on the gray matter characteristics of trait anxiety.

METHODS

Structural magnetic resonance imaging (MRI) data from 393 individuals aged 65 years or older were used. Regions of interest (ROIs) included the amygdala, anterior cingulate cortex (ACC), insula, orbitofrontal cortex (OFC), and temporal cortex. Trait anxiety was measured by the State-Trait Anxiety Inventory (STAI). Depression and depressive symptoms were measured using DSM-IV criteria and the Center for Epidemiological Studies Depression Scale (CESD).

RESULTS

After adjustments for sociodemographics and health-related variables, anxiety had a significant influence on the gray matter characteristics in all cortical ROIs. First, in participants without depression antecedents, higher trait anxiety was associated with a larger cortical thickness in all cortical ROIs. Second, in participants with a previous history of depression, higher trait anxiety was associated with a smaller cortical thickness in all cortical ROIs.

CONCLUSIONS

These results suggest that anxiety is related to cortical thickness differently in healthy older adults and in older adults with psychiatric antecedents. Anxiety associated with thinner cortical areas could reflect symptoms of a specific type of depression or a vulnerability to develop depression.

New research on anxiety disorders in the elderly and an update on evidence-based treatments

Anxiety disorders are frequently encountered in the elderly, but they are largely undetected and untreated. Epidemiological studies indicate a prevalence ranging from 1.2 to 15 %. With the exception of generalized anxiety disorder and agoraphobia, which can often start in late life, most anxiety disorders in older patients are chronic and have their onset earlier in life. Anxiety disorders are an often unrecognized cause of distress, disability, and mortality risk in older adults, and they have been associated with cardiovascular disease, stroke, and cognitive decline. The mechanisms of anxiety in older adults differ from that in younger adults due to age-related neuropathology, as well as the loss and isolation so prominent in late life. Our review intends to provide a comprehensive summary of the most recent research done in the field of anxiety disorders in the elderly. Recent findings in clinical research, neuroimaging, neuroendocrinology, and neuropsychology are covered. An update on treatment options is discussed, including pharmacological and non-pharmacological alternatives.

Emotion reactivity and regulation in late-life generalized anxiety disorder: functional connectivity at baseline and post-treatment

OBJECTIVES

Generalized anxiety disorder (GAD) is one of the most prevalent mental disorders in the elderly, but its functional neuroanatomy is not well understood. Given the role of emotion dysregulation in GAD, we sought to describe the neural bases of emotion regulation in late-life GAD by analyzing the functional connectivity (FC) in the Salience Network and the Executive Control Network during worry induction and worry reappraisal.

METHODS

The study included 28 elderly GAD and 31 non-anxious comparison participants. Twelve elderly GAD completed a 12-week pharmacotherapy trial. We used an in-scanner worry script that alternates blocks of worry induction and reappraisal. We assessed network FC, using the following seeds: anterior insula (AI), dorsolateral prefrontal cortex (dlPFC), the bed nucleus of stria terminalis (BNST), and the paraventricular nucleus (PVN).

RESULTS

GAD participants exhibited greater FC during worry induction between the left AI and the right orbitofrontal cortex, and between the BNST and the subgenual cingulate. During worry reappraisal, the non-anxious participants had greater FC between the left dlPFC and the medial PFC, as well as between the left AI and the medial PFC, and elderly GAD patients had greater FC between the PVN and the amygdala. Following 12 weeks of pharmacotherapy, GAD participants had greater connectivity between the dlPFC and several prefrontal regions during worry reappraisal.

CONCLUSION

FC during worry induction and reappraisal points toward abnormalities in both worry generation and worry reappraisal. Following successful pharmacologic treatment, we observed greater connectivity in the prefrontal nodes of the Executive Control Network during reappraisal of worry.

The ages of anxiety--differences across the lifespan in the default mode network functional connectivity in generalized anxiety disorder

OBJECTIVES

Generalized anxiety disorder (GAD) is one of the most prevalent anxiety disorders, but its neural basis is relatively understudied. This study aims to characterize the functional connectivity in the default mode network (DMN) in GAD across the lifespan.

DESIGN AND SETTINGS

Functional and structural magnetic resonance imaging data were collected with subjects at rest. We analyzed the resting state functional connectivity patterns in the DMN for 27 GAD participants and 39 non-anxious comparison participants. Using a two-way analysis of variance, we explored the interaction between age and GAD status on functional connectivity. In GAD participants, we analyzed the correlation of functional connectivity indices with the duration of illness and worry severity.

RESULTS

The age-by-anxiety interaction showed a greater anxiety effect on the functional connectivity between the posterior cingulate seed and the medial prefrontal cortex for the older group relative to the younger participants. Longer duration of illness was positively correlated with greater functional connectivity between the posterior cingulate cortex and the insula. Worry severity was inversely correlated with the functional connectivity between the posterior cingulate cortex seed and the medial prefrontal cortex.

CONCLUSION

The presence of GAD, longer duration of illness, and more severe worry exacerbate the effects of age on the functional connectivity in the DMN. These results support the need for tailored research and interventions in late-life anxiety.

Neural structures, functioning and connectivity in Generalized Anxiety Disorder and interaction with neuroendocrine systems: a systematic review

BACKGROUND

Research on the neurobiological basis of Generalized Anxiety Disorder (GAD) has considerably expanded in recent years. However, many studies investigated different domains and used different methods and paradigms. Therefore, this review aims to integrate the findings to date and to identify the core correlates of neurobiological underpinnings of GAD discovered so far.

METHODS

We conducted a systematic review of original papers investigating neural correlates, connectivity, or structural changes as well as reporting changes in the serotonergic system, noradrenergic system and cortisol levels in DSM-IV-defined GAD samples until December 2013.

RESULTS

Studies have identified abnormal amygdala and prefrontal cortex activation in patients and decreased functional connectivity between these areas. Furthermore, studies showed increased gray matter volume and decreased structural connectivity between these structures. Neuroendocrine findings are less consistent, but increased reactivity of the noradrenergic system and perpetuations in the cortisol secretion have been reported.

LIMITATIONS

Only studies on DSM-IV defined Generalized Anxiety Disorder which employed a group comparison were included.

CONCLUSIONS

Current research suggests a distinct set of neurobiological alterations in Generalized Anxiety Disorder. However, future research on the interaction between these structures and systems and on the specificity of these findings in relation to other mental disorders is urgently needed.

Lack of gender effects on gray matter volumes in adolescent generalized anxiety disorder

BACKGROUND

Previous epidemiological and clinical studies have reported gender differences in prevalence and clinical features of generalized anxiety disorder (GAD). Such gender differences in clinical phenomenology suggest that the underlying neural circuitry of GAD could also be different in males and females. This study aimed to explore the possible gender effect on gray matter volumes in adolescents with GAD.

METHODS

Twenty-six adolescent GAD patients and 25 healthy controls participated and underwent high-resolution structural magnetic resonance scans. Voxel-based morphometry (VBM) was used to investigate gray matter alterations.

RESULTS

Our study revealed a significant diagnosis main effect in the right putamen, with larger gray matter volumes in GAD patients compared to healthy controls, and a significant gender main effect in the left precuneus/posterior cingulate cortex, with larger gray matter volumes in males compared to females. No gender-by-diagnosis interaction effect was found in this study.

LIMITATIONS

The relatively small sample size in this study might result in a lack of power to demonstrate gender effects on brain structure in GAD.

CONCLUSIONS

The results suggested that there are differences in gray matter volumes between males and females, but gray matter volumes in GAD are not influenced by gender.

Brain cortical thickness in ADHD: age, sex, and clinical correlations

OBJECTIVE

Longitudinal magnetic resonance imaging (MRI) studies have shown reduced cortical thickness (CT) in individuals with ADHD, but this abnormality disappears with age, suggesting developmental delay. However, cross-sectional MRI studies have shown reduced CT, suggesting abnormal development. The aim of this study was to compare whole-brain CT in male and female children, adolescents, and adults with ADHD with whole-brain CT in matched control participants.

METHOD

MRI scans were performed on ADHD and control participants.

RESULTS

CT data revealed differences in right hemisphere (RH) only. Reduced CT was observed predominantly in the frontoparietal region. However, increased CT was observed predominantly in the occipital lobe. The CT differences were correlated with severity of ADHD. Analysis of sex differences revealed that location, number, and magnitude of CT differences were different between males and females in each age group.

CONCLUSION

These data support the hypothesis that anatomical abnormalities in ADHD represent abnormal development rather than developmental delay.

Executive skills in older adults with GAD: relations with clinical variables and CBT outcome

Although cognitive behavior therapy (CBT) is an effective intervention for treating generalized anxiety disorder (GAD) in older adults, researchers are now considering augmenting the therapy to enhance outcome. We are also long overdue in identifying moderators of CBT response (e.g., cognitive abilities) in late life anxiety. The goals of the current investigation were to examine performance on verbal versus nonverbal tests of executive skills (ES) and to test the relation between ES and clinical indices in older GAD patients. Hierarchical and logistic regression models identified baseline ES predictors of premature termination, homework compliance and quality, and indices of cognitive restructuring, an essential component of CBT. Although the analyses of response on symptom measures did not reveal any significant baseline predictors, an alternative ES grouping scheme showed that those whose ES improved during CBT also responded best in terms of worry reduction. These findings can be applied to the optimization of treatment for older anxiety patients, who are an underserved demographic group.

The role of the amygdala in the pathophysiology of panic disorder: evidence from neuroimaging studies

Although the neurobiological mechanisms underlying panic disorder (PD) are not yet clearly understood, increasing amount of evidence from animal and human studies suggests that the amygdala, which plays a pivotal role in neural network of fear and anxiety, has an important role in the pathogenesis of PD. This article aims to (1) review the findings of structural, chemical, and functional neuroimaging studies on PD, (2) relate the amygdala to panic attacks and PD development, (3) discuss the possible causes of amygdalar abnormalities in PD, (4) and suggest directions for future research.

White-matter abnormalities in the right posterior hemisphere in generalized anxiety disorder: a diffusion imaging study

BACKGROUND

Prior imaging studies have shown structural, functional and biochemical impairments in patients with generalized anxiety disorder (GAD), particularly in the right hemisphere. In this study we investigated, for the first time to the best of our knowledge, the white-matter microstructure organization in GAD.

METHOD

A total of 12 patients with DSM-IV GAD and 15 matched healthy controls underwent a magnetic resonance imaging session of diffusion weighted imaging, exploring white-matter water molecules by the means of apparent diffusion coefficients (ADCs). Regions of interests were placed in the frontal, parietal, temporal and occipital lobes and in the splenium and genu of the corpus callosum, bilaterally.

RESULTS

ADC measures were significantly greater in patients with GAD in the right splenium and right parietal cortex compared with healthy controls (p⩽0.002). No significant correlations between ADCs and age or clinical variables were found.

CONCLUSIONS

We provide evidence that GAD is associated with disrupted white-matter coherence of posterior right hemisphere regions, which may partly sustain the impaired cognitive regulation of anxiety. Future diffusion imaging investigations are expected to better elucidate the communication between the parietal cortex and other right hemisphere regions in sustaining the cognitive processing of social and emotional stimuli in patients with GAD.

Structural evidence for involvement of a left amygdala-orbitofrontal network in subclinical anxiety

Functional neuroimaging implicates hyperactivity of amygdala-orbitofrontal circuitry as a common neurobiological mechanism underlying the development of anxiety. Less is known about anxiety-related structural differences in this network. In this study, a sample of healthy adults with no history of anxiety disorders completed a 3T MRI scan and self-report mood inventories. Post-processing quantitative MRI image analysis included segmentation and volume estimation of subcortical structures, which were regressed on anxiety inventory scores, with depression scores used to establish discriminant validity. We then used a quantitative vertex-based post-processing method to correlate (1) anxiety scores and (2) left amygdala volumes with cortical thickness across the whole cortical mantle. Left amygdala volumes predicted anxiety, with decreased amygdala volume associated with higher anxiety on both state and trait anxiety measures. A negative correlation between left amygdala volume and cortical thickness overlapped with a positive correlation between anxiety and cortical thickness in left lateral orbitofrontal cortex. These results suggest a structural anxiety network that corresponds with a large body of evidence from functional neuroimaging. Such findings raise the possibility that structural abnormalities may result in a greater vulnerability to anxiety or conversely that elevated anxiety symptoms may result in focal structural changes.

Different white matter abnormalities between the first-episode, treatment-naive patients with posttraumatic stress disorder and generalized anxiety disorder without comorbid conditions

BACKGROUND

This study compared brain white matter integrity in two groups of patients with DSM-IV anxiety disorders.

METHOD

Seventeen patients with posttraumatic stress disorder (PTSD), 20 with generalized anxiety disorder (GAD), and 28 healthy controls were assessed on diffusion tensor imaging.

RESULTS

As compared to healthy controls, increased fractional anisotropy (FA) in left superior frontal gyrus in PTSD patients, and increased FA in right postcentral gyrus in GAD subjects were exhibited. Furthermore, patients with PTSD showed reduced FA in right anterior cingulate gyrus relative to GAD subjects. However, there was no significant correlation between the FA value of any altered region and the severity of PTSD or GAD.

LIMITATIONS

The sample studied can be considered small. Gender and educational level were not well-matched among the groups.

CONCLUSIONS

We tentatively speculate that abnormal white matter integrity of right anterior cingulate gyrus is an important neuroimaging marker of PTSD that distinguishes it from other anxiety disorders such as GAD.

Risky decision-making in older adults without cognitive deficits: an fMRI study of VMPFC using the Iowa Gambling Task

Some older adults without neurological disease exhibit impaired decision-making in risky, nontransparent situations, like the Iowa Gambling Task (IGT). The prefrontal cortices are particularly vulnerable to age-related decline, and numerous studies implicate the ventromedial prefrontal cortex (VMPFC) in successful IGT performance. However, the relationship between IGT performance and VMPFC function in older adults has not yet been tested by fMRI. In the present study, older adults with seemingly no cognitive impairments performed the IGT and a non-gambling control task during fMRI. Group analyses indicate that in these older adults, regardless of IGT performance level, a right VMPFC subregion is activated during the IGT, while successful IGT performance is correlated with left VMPFC activation, suggesting that bilateral VMPFC during risky, nontransparent situations may contribute to successful decision-making in older adults. Individual subject analyses reveal substantial variation regarding the extent and location of VMPFC activation during the IGT, a finding not captured in the group analysis: There is no correlation between IGT performance and extent of activation in the right VMPFC, although there is such a correlation between left VMPFC activation and IGT performance.

Psychiatric disorders in the elderly

Recent research has shown that depression, anxiety disorders, and psychosis are more common than previously supposed in elderly populations without dementia. It is unclear whether the frequency of these disorders increases or decreases with age. Clinical expression of psychiatric disorders in old age may be different from that seen in younger age groups, with less and often milder symptoms. Concurrently, comorbidity between different psychiatric disorders is immense, as well as comorbidity with somatic disorders. Cognitive function is often decreased in people with depression, anxiety disorders, and psychosis, but whether these disorders are risk factors for dementia is unclear. Psychiatric disorders in the elderly are often related to cerebral neurodegeneration and cerebrovascular disease, although psychosocial risk factors are also important. Psychiatric disorders, common among the elderly, have consequences that include social deprivation, poor quality of life, cognitive decline, disability, increased risk for somatic disorders, suicide, and increased nonsuicidal mortality.

Elevated cortisol in older adults with generalized anxiety disorder is reduced by treatment: a placebo-controlled evaluation of escitalopram

BACKGROUND

Generalized anxiety disorder (GAD) is a common disorder in older adults, which has been linked to hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis in this age group. The authors examined whether treatment of GAD in older adults with a selective serotonin reuptake inhibitor (SSRI) corrects this HPA axis hyperactivity.

METHODS

The authors examined adults aged 60 years and older with GAD in a 12-week randomized controlled trial comparing the SSRI escitalopram with placebo. The authors collected salivary cortisol at six daily time points for 2 consecutive days to assess peak and total (area under the curve) cortisol, both at baseline and posttreatment.

RESULTS

Compared with placebo-treated patients, SSRI-treated patients had a significantly greater reduction in both peak and total cortisol. This reduction in cortisol was limited to patients with elevated (above the median) baseline cortisol, in whom SSRI-treated patients showed substantially greater reduction in cortisol than did placebo-treated patients. Reductions in cortisol were associated with improvements in anxiety. Additionally, genetic variability at the serotonin transporter promoter predicted cortisol changes.

CONCLUSIONS

SSRI treatment of GAD in older adults reduces HPA axis hyperactivity. Further research should determine whether these treatment-attributable changes are sustained and beneficial.

Reduced right frontal cortical thickness in children, adolescents and adults with ADHD and its correlation to clinical variables: a cross-sectional study

OBJECTIVE

Some longitudinal magnetic resonance imaging (MRI) studies have shown reduced volume or cortical thickness (CT) in the frontal cortices of individuals with attention-deficit/hyperactivity disorder (ADHD). These studies indicated that the aforementioned anatomical abnormalities disappear during adolescence. In contrast, cross-sectional studies on adults with ADHD have shown anatomical abnormalities in the frontal lobe region. It is not known whether the anatomical abnormalities in ADHD are a delay or a deviation in the encephalic maturation. The aim of this study was to compare CT in the frontal lobe of children, adolescents and adults of both genders presenting ADHD with that in corresponding healthy controls and to explore its relationship with the severity of the illness.

METHOD

An MRI scan study was performed on never-medicated ADHD patients. Twenty-one children (6-10 year-olds), twenty adolescents (14-17 year-olds) and twenty adults (25-35 year-olds) were matched with healthy controls according to age and sex. CT measurements were performed using the Freesurfer image analysis suite.

RESULTS

The data showed regions in the right superior frontal gyrus where CT was reduced in children, adolescents and adults with ADHD in contrast to their respective healthy controls. The CT of these regions correlated with the severity of the illness.

CONCLUSIONS

In subjects with ADHD, there is a thinning of the cortical surface in the right frontal lobe, which is present in the children, adolescents and in adults.

Novel approaches to treatment of generalized anxiety disorder

PURPOSE OF REVIEW

The present paper reviews recent studies on the clinical presentation of generalized anxiety disorder (GAD) and the current level of evidence for treatment with medications and psychotherapy.

RECENT FINDINGS

An apprehensive state of mind, regardless of the quality of stimuli, is at the core of GAD, causing a pervasive cognitive dysfunction that is separate from that seen in depression and obsessive compulsive disorder. When treatments reduce anxiety-related symptoms and insomnia, patients report a restoration of social functioning, probably as a consequence of improved decision-making, cooperative skills, and risk assessment. Late-onset GAD symptoms in the elderly may be caused or aggravated by cerebrovascular events, loneliness, bereavement, substance use, and the prospect of death. Insomnia in GAD may be primary or caused by common medications. Practice guidelines fail to capture the needs of the entire range of patients with GAD as they build on patients without comorbidity who have been selected for phase III trials. They are also biased to reduce cost.

SUMMARY

The past 10 years have seen a range of safe and effective treatments for GAD. Late-onset GAD presents a new challenge to researchers and practitioners. The current state of knowledge about GAD does not justify radical revisions of the diagnostic criteria in the ongoing revisions of the Diagnostic and Statistical Manual of Mental Disorders-IV and the International Statistical Classification of Diseases-10 nosologies.