Nonanxious Subjects Research Articles

Plasma Nesfatin-1 Levels and its Relationship with Anxiety Levels in Obesity Diagnosed Population: A Controlled Study

Objective: Nesfatin-1 is a satiety neuropeptide involved in the regulation of metabolic pathways and food intake. Some studies have shown nesfatin-1 to be also associated with stress responses and stress-related behaviors. In the present study, we evaluated nesfatin-1 levels in obese individuals and investigated whether nesfatin-1 levels could be associated with anxiety levels in obese populations. Methods: Fifty-eight obese (29 anxious and 29 non-anxious) patients and 25 healthy control subjects between 18 and 65 years old were enrolled in the study. Plasma nesfatin-1 levels were measured with a commercial enzyme-linked immunosorbent assay, and anxiety levels were measured using the Hospital Anxiety and Depression Scale.Results: Plasma nesfatin-1 levels were significantly lower in both obese and anxious subjects and obese and non-anxious subjects than in the control group. No significant differences were found between the obese+anxious group and the obese+nonanxious group.Conclusion: Our results suggest that plasma nesfatin-1 levels are decreased and not associated with anxiety levels in obese populations

Standard of proof and intolerance of uncertainty in obsessive-compulsive disorder and social anxiety disorder

Background and objectivesResearchers have identified intolerance of uncertainty (IU) as a dysfunctional thought that contributes to OCD. Case examples of OCD suggest that uncertainty and anxiety persist despite low likelihoods of feared outcomes. In this study we examined how people with OCD react to minimal amounts of uncertainty relative to non-anxious individuals and a clinical comparison group of people with social anxiety disorder (SAD). MethodsWe created a questionnaire to measure the distress people feel when there is only minimal uncertainty regarding a given outcome and if they prefer situations with the certainty of negative outcomes in the present versus living with uncertainty. Part two of our study tested whether IU is related to performance on neutral and idiographic versions of the Beads Task. ResultsOCD and SAD subjects reacted to hypothetical scenarios involving minimal risk with greater negative affect than did non-anxious subjects; however, after repeating analyses to account for comorbid disorders, OCD subjects’ scores did not differ from those of non-anxious subjects. Only SAD subjects showed a preference for negative information in the present versus the uncertainty of a future outcome. Part two of our study revealed that self-reported IU was only marginally associated with performance on the neutral Beads Task. LimitationsHigh rates of comorbidity made it difficult to identify the specific relationship of IU with other anxiety disorders. ConclusionsIU for general, non-OCD specific scenarios may not figure prominently in all individuals with OCD, but rather may play a larger, more consistent role in anxiety disorders such as SAD. Additionally, the number of beads or words viewed on Beads Task may be an inadequate behavioral measure of IU.

Mediating effect of neurocognition between severity of symptoms and social-occupational function in anxious depression.

Major depressive disorder (MDD) is associated with neurocognitive impairment and reduced social-occupational function. However, neurocognition and social-occupational function in patients with anxious depression have been under-investigated. An increasing number of studies have demonstrated that neurocognition plays an important role in social-occupational function. The objective of this study was to investigate the association of severity of symptoms, neurocognition and social-occupational function in patients with anxious depression. Using a cross-sectional design, 214 patients with MDD were recruited consecutively and evaluated using the 17-item Hamilton Depression Rating scale (HAMD-17), the MATRICS Consensus Cognitive Battery (MCCB) and the Global Assessment of Functioning (GAF). The prevalence of anxious depression in MDD patients was 64.5%. Compared to non-anxious subjects, the anxious group had more severe symptoms. Moreover, in the anxious group, social-occupational function was associated with several domains of symptoms and neurocognition, while social-occupational function was associated with only one aspect of depressive symptoms (cognitive disturbance) in the non-anxious group. In addition, there was a mediating effect of neurocognition on the association between the severity of symptoms and social-occupational function in the anxious group. The major limitation of the present study is the use of a cross-sectional design that is unable to illuminate causal relationships. Our results suggest that the severity of symptoms is negatively associated with neurocognition and social-occupational function and that neurocognition is positively associated with social-occupational function in patients with anxious depression.

Interaction of induced anxiety and verbal working memory: influence of trait anxiety

This study examines the influence of trait anxiety on working memory (WM) in safety and threat. Interactions between experimentally induced anxiety and WM performance (on different cognitive loads) have been reported in healthy, nonanxious subjects. Differences in trait anxiety may moderate these interactions. Accordingly, these interactions may be potentiated by high trait anxiety (HTA), or show a resilient pattern that protects cognitive performance. HTA and low trait anxiety (LTA) were defined by a median split of scores on the trait component of the state-trait anxiety inventory. Sustained anxiety was evoked by a probabilistic exposure to an aversive scream, and was measured by eyeblink startle and self-report. WM was tested using an n-back task (1-, 2-, and 3-back). Results revealed that, as expected, the HTA group reported greater anxiety during the task. However, trait anxiety did not impact the modulation of WM performance by induced anxiety. Notably, HTA influenced anxiety-potentiated startle (startle during threat minus startle during safe; APS) differently as a function of memory load. Accordingly, APS decreased with increasing WM load, but HTA antagonized this reduction. The HTA group showed no impairment on the 3-back WM task despite a higher APS. The amplified APS could be associated with the increase in effort-related cognitive arousal. Furthermore, this third replication of the interaction of induced anxiety by load on WM performance testifies to the robustness of the unique interplay between anxiety and WM.

Discriminating between Anxious and Non-Anxious Subjects Using the Toronto Hospital Alertness Test.

Alertness designates the internal feeling of wakefulness or arousal and is often described to be linked to the level of anxiety. An adequate level of anxiety favoring the alertness needed to deal with a faced specific situation efficiently; too much anxiety can result in failure to process information and respond appropriately. Thus, it would be of interest to verify if different alertness profiles can be observed depending on anxiety level. The Toronto Hospital Alertness Test (THAT) is a test designed to measure alertness. The present survey's aim is to verify if the THAT allows observing different alertness profile between self-described anxious and non-anxious subjects. Subjects >18 years were selected from online databases in three countries (Canada, USA, and UK). All respondents filled in a Hospital Anxiety Depression Scale questionnaire, and only those self-classified as anxious or non-anxious (HAD-A ≥11 or ≤7, respectively) took part to the survey and were asked to complete the THAT. Among 616 respondents retained in the survey, 414 were self-assessed as anxious and 202 as non-anxious. The mean THAT score for anxious and non-anxious subjects was 21.4 and 38.9, respectively. A receiver operating characteristic (ROC) curve of THAT scores indicated that a threshold score of 30 was required to achieve good sensitivity (86.7%) and specificity (88.6%), with good discriminatory power [an area under the curve (AUC) of 0.938]. As age was determined to be a potential confounder, subjects were age-matched giving a ROC with an AUC of 0.931, with good sensitivity (88.5%) and specificity (89.3%), and the threshold remaining at 30. The internal reliability of THAT in anxious subjects was good (Cronbach alpha = 0.84). No independent verification of anxious or non-anxious status or other eligibility criteria was done. The alertness profiles of self-defined anxious and non-anxious subjects observed on THAT are different. Based on a subject's alertness profile, it is possible to discriminate between self-defined anxious and non-anxious, using THAT, with good specificity and sensitivity at a threshold score of 30.

No effects of psychosocial stress on memory retrieval in non-treated young students with Generalized Social Phobia

Generalized Social Phobia (GSP) is a common anxiety disorder that produces clear social life disruptions. There is no consensus on the specific processes involved in its development, but the role of the hypothalamic-pituitary-adrenal (HPA) axis has been suggested. This study analyzed the effects of the cortisol response to the Trier Social Stress Test (TSST) on the memory retrieval of pictures with different emotional valences in 45 non-treated young students with GSP and 50 non-anxious (NA) subjects (mean=19.35years, SD=0.18). No differences were found in the cortisol response of GSP and NA subjects to the TSST and control sessions. In addition, psychosocial stress impaired memory retrieval in both the GSP and NA groups, with no differences between them. Regarding the sex factor, no effects were found in the cortisol response to the TSST. However, during the encoding session, GSP men had higher cortisol levels than GSP women and NA subjects. There was also a significant interaction between sex and stress exposure on memory retrieval. Women recognized more unpleasant and neutral pictures than men; however, under stress, the women’s advantage disappeared, and the men’s performance improved. Sex also interacted with social phobia on positive mood, with GSP women exposed to the TSST showing the lowest positive mood. These results suggest that GSP subjects do not present an HPA axis sensitization to psychosocial stress, and they emphasize the importance of Sex in understanding stress effects on memory.

The role of anxiety in the perception of technological hazards – A cross-sectional study on cell phones and masts

BackgroundRisk perception is determined by parameters related to the nature of the risk, as well as inherent to the individual perceiving this risk. This study was designed to provide a better understanding of the role of personality, especially anxiety traits, on risk perception. It compared representations of two different risks, smoking (with known and generally accepted adverse health effects) and cell phones (whose hazardous potency is still controversial), each presented in two different forms of exposure, active (smokers and cell phone users) and passive (passive smoking and exposure to cell phone masts). MethodsA self-administered questionnaire sent to volunteer subjects collected sociodemographic and exposure data. It measured the perceived risk as well as 11 psychometric properties of risk using visual analogue scales (values ranging from 0 to 10). An anxiety trait was evaluated by the Spielberger questionnaire. ResultsIn all, 72% of the questionnaires sent were returned. Mean declared risk scores attributed to passive and active smoking were higher (8.75 and 8.31 respectively) than those attributed to cell phones and masts (4.44 and 4.73 respectively). However, scores for the 11 psychometric properties of the risk attributed to cell phones were higher than those associated with smoking, especially for dissatisfaction with information (6.71 and 7.36 respectively for cell phones and masts versus 1.75 and 2.18 for passive and active smoking) and the capacity of authorities to master the risk (6.45 and 6.65 for cell phones and masts versus 4.72 and 4.40 for passive and active smoking). Anxiety did not directly influence the risk scores attributed to these 4 forms of exposure but was predictive of the way in which subjects perceived the risk in terms of two essential properties: uncertainty concerning the effects on health and the potential to trigger health catastrophes. Indeed anxious subjects are more certain about the hazards of cell phones and masts than non-anxious subjects (P=0.008 et P≤0.001) and attributed a higher catastrophic potential (P=0.02 and P=0.004). ConclusionThis study suggests that subjects with an anxious profile are affected by the destabilizing nature of uncertain knowledge concerning the hazardous potency of new technologies and of the controversies concerning this hazard.

Anxiety is associated with a reduction in both mortality and major adverse cardiovascular events five years after coronary stenting

Previous studies in post-myocardial infarction patients with heart failure have documented that high anxiety levels are associated with increased mortality. In this prospective study, we determined the impact of anxiety on long-term event risk in stable coronary heart disease (CHD) patients treated with percutaneous coronary interventions (PCIs). A total of 470 patients referred for PCI completed the Hospital Anxiety and Depression Scale (HADS) before undergoing stent implantation. Over a five-year follow-up period, data on survival, occurrence of major adverse cardiovascular events (MACEs) and repeat revascularization were obtained from n = 462 participants (98.3%). All-cause mortality rates differed significantly across the four quartiles of the HADS anxiety subscale, the lowest number of deaths (1.9%) being seen in patients with the highest HADS-A quartile (scores ≥ 10) as compared to those in the three lower quartiles (11.8%, odds ratio = 0.14, 95%-confidence interval (95% CI): 0.03-0.60, p = 0.002). Cox regression models adjusted for a variety of potential somatic and procedural confounders confirmed the results from the univariate analyses (hazard ratio (HR) = 0.21, 95% CI: 0.05-0.91, p = 0.037). There were also fewer MACEs in anxious patients as compared to non-anxious subjects (HR = 0.34, 95% CI: 0.14-0.80, p = 0.014). In contrast, anxious patients had a higher rate of repeat revascularization (26.4% versus 16.6%, p = 0.033). In CHD patients undergoing elective PCI, higher anxiety levels are positively associated with survival and reduce the risk for MACE during the first five years after index PCI. The beneficial effects of anxiety on cardiovascular mortality and morbidity suggest that a differentiated approach to diagnosing and treating anxiety in CHD patients is warranted.

Fear of negative evaluation and attentional bias for facial expressions: An event-related study

Numerous studies have shown an exacerbation of attentional bias towards threat in anxiety states. However, the cognitive mechanisms responsible for these attentional biases remain largely unknown. Further, the authors outline the need to consider the nature of the attentional processes in operation (hypervigilance, avoidance, or disengagement). We adapted a dot-probe paradigm to record behavioral and electrophysiological responses in 26 participants reporting high or low fear of evaluation, a major component of social anxiety. Pairs of faces including a neutral and an emotional face (displaying anger, fear, disgust, or happiness) were presented during 200ms and then replaced by a neutral target to discriminate. Results show that anxious participants were characterized by an increased P1 in response to pairs of faces, irrespective of the emotional expression included in the pair. They also showed an increased P2 in response to angry–neutral pairs selectively. Finally, in anxious participants, the P1 response to targets was enhanced when replacing emotional faces, whereas non-anxious subjects showed no difference between the two conditions. These results indicate an early hypervigilance to face stimuli in social anxiety, coupled with difficulty in disengaging from threat and sustained attention to emotional stimuli. They are discussed within the framework of current models of anxiety and psychopathology.

The impact of anxiety on lactose intolerance symptoms

BACKGROUND Lactose malabsorption is variably associated with lactose intolerance (LI). The determinants of symptom onset have not yet been completely identified. Visceral sensitivity may play a role in the pathogenesis of functional symptoms; an increasing bulk of clinical and research data suggests the importance of the brain-gut interaction in intestinal bowel syndrome. AIM: To assess the impact of anxiety on LI symptoms, and the correlation between gas production during Lactose Breath test (LBT) and the intensity of gastrointestinal symptoms (GI) in anxious (A) and non-anxious (NA) patients. METHODS: LBT was carried out in 104 consecutive participants referred to our Gastroenterology Unit. GI symptoms were evaluated using the visual analogue scale (VAS: 0-10) throughout the LBT. All patients completed the HADS to determine anxiety. RESULTS LBT was positive in 70/104 (67%) participants; 49/ 104 (47%) showed significant anxiety symptoms (>10 items). In A subjects we did not find any significant correlation between gas levels and abdominal LI symptoms scores throughout the LBT. A subject showed higher scores for all LI symptoms as compared with other participants, independently of LBT results. NA pts with positive LBT showed higher scores for all LI symptoms, as compared to negative subjects. LIMITATIONS: The predominant gender is female but it is in agreement with literature data that show a preponderance of IBS in women. CONCLUSIONS: A status significantly influences the severity of all LI symptoms and does not strictly correlate with lactase deficiency. Conversely, among NA subjects LI symptoms increase along with H2 production. Anxiety seems to be a confounding factor in IBS pts.

The effect of cognitive load in emotional attention and trait anxiety: An eye movement study

There is extensive debate on the automaticity of attentional processing of emotional information. One core feature of automaticity is the independence of processing emotion from factors that can affect attention such as cognitive load. In the present study we investigated whether processing of emotional facial expressions was dependent on cognitive load using a visual search paradigm. Manual responses as well as eye movements were recorded. Although both measures showed that emotional information captured attention more strongly than neutral information, manual responses indicated that load slowed reaction times only for “pop-out” emotion conditions; no increase was seen for all-emotional displays. This suggests that the saliency of emotion was reduced, but eye movement data showed that effects were caused by improvements for all-emotional displays in target processing efficiency. Additionally, trait anxiety did not influence threat processing, but costs were observed under load that were not present for nonanxious subjects. Our results suggest that while load can interfere with task performance, it may not affect emotion processing. Our findings highlight the importance of eye movement measures in accounting for differences in manual response data and provide novel support to theories of anxiety.

Measuring Manual Dexterity and Anxiety in Divers Using a Novel Task at 35–41 m

Nitrogen narcosis has a detrimental impact on the manual dexterity of divers and prior research has suggested that this impairment may be magnified by anxiety. Preliminary findings of the effects of depth (i.e., narcosis) and subjective anxiety on a novel test of manual dexterity are presented. There were 45 subjects who were given a test of manual dexterity once in shallow water (1-10 m/3-33 ft) and once in deep water (35-41 m/115-135 ft). Subjective anxiety was concurrently measured in 33 subjects who were split into 'non-anxious' and 'anxious' groups for each depth condition. Subjects took significantly longer (seconds) to complete the manual dexterity task in the deep (mean = 52.8; SD = 12.1) water compared to the shallow water (mean = 46.9; SD = 8.4). In addition, anxious subjects took significantly longer to complete the task in the deep water (mean = 48.6; SD = 6.8) compared to non-anxious subjects (mean = 53.2; SD = 9.9), but this was not the case in the shallow water. This selective effect of anxiety in deep water was taken as evidence that anxiety may magnify narcotic impairments underwater. It was concluded that the test of manual dexterity was sensitive to the effects of depth and will be a useful tool in future research.

Prevalence of anxiety disorders and anxiety subtypes in patients with Parkinson's disease

Anxiety disorders are common in Parkinson's disease (PD), but are not well characterized. This study determined the prevalence and clinical correlates of all DSM-IV-TR anxiety disorder diagnoses in a sample of 127 subjects with idiopathic PD who underwent comprehensive assessments administered by a psychiatrist and neurologist. A panel of six psychiatrists with expertise in geriatric psychiatry and/or movement disorders established by consensus all psychiatric diagnoses. Current and lifetime prevalence of at least one anxiety disorder diagnosis was 43% (n = 55) and 49% (n = 63), respectively. Anxiety disorder not otherwise specified, a DSM diagnosis used for anxiety disturbances not meeting criteria for defined subtypes, was the most common diagnosis (30% lifetime prevalence, n = 38). Compared with nonanxious subjects, panic disorder (n = 13) was associated with earlier age of PD onset [50.3 (12.2) vs. 61.0 (13.7) years, P < 0.01], higher rates of motor fluctuations [77% (10/13) vs. 39% (25/64), P = 0.01] and morning dystonia [38% (5/13) vs. 13% (8/62), P < 0.03]. This high prevalence of anxiety disorders, including disturbances often not meeting conventional diagnostic criteria, suggests that anxiety in PD is likely underdiagnosed and undertreated and refined characterization of anxiety disorders in PD is needed. In addition, certain anxiety subtypes may be clinically useful markers associated with disease impact in PD.

Anxiety and cognitive efficiency: Differential modulation of transient and sustained neural activity during a working memory task

According to the processing-efficiency hypothesis (Eysenck, Derakshan, Santos, & Calvo, 2007), anxious individuals are thought to require greater activation of brain systems supporting cognitive control (e.g.,dorsolateral prefrontal cortex; DLPFC) in order to maintain equivalent performance to nonanxious subjects. A recent theory of cognitive control (Braver, Gray, & Burgess, 2007) has proposed that reduced cognitive efficiency might occur as a result of changes in the temporal dynamics of DLPFC recruitment. In this study, we used a mixed blocked/ event-related fMRI design to track transient and sustained activity in DLPFC while high- and low-anxious participants performed a working memory task. The task was performed after the participants viewed videos designed to induce neutral or anxiety-related moods. After the neutral video, the high-anxious participants had reduced sustained but increased transient activation in working memory areas, in comparison with low-anxious participants. The high-anxious group also showed extensive reductions in sustained activation of "default-network" areas (possible deactivation). After the negative video,the low-anxiety group shifted their activation dynamics in cognitive control regions to resemble those of the high-anxious group. These results suggest that reduced cognitive control in anxiety might be due to a transient, rather than sustained, pattern of working memory recruitment. Supplementary information for this study may be found at www.psychonomic.org/archive.

Salivary cortisol is associated with diagnosis and severity of late-life generalized anxiety disorder

Age-associated alterations in hypothalamic-pituitary-adrenal (HPA) axis functioning may make individuals more susceptible to HPA dysregulation in the context of mood and anxiety disorders. Little to no research has been done to examine HPA axis function in generalized anxiety disorder (GAD), particularly in late-life GAD, the most prevalent anxiety disorder in the elderly. The study sample consisted of 71 GAD subjects and 40 nonanxious comparison subjects over 60 years of age. We examined the hypotheses that elderly individuals with GAD will have elevated salivary cortisol levels compared to nonanxious subjects, and that elevated cortisol levels in GAD will be associated with measures of symptom severity. We report that late-life GAD is characterized by elevated basal salivary cortisol levels, with higher peak cortisol levels and larger areas under the curve, compared to nonanxious subjects. Additionally, severity of GAD as measured by the GAD Severity Scale and the Penn State Worry Questionnaire are positively correlated with cortisol levels. These data demonstrate HPA axis dysfunction in late-life GAD and suggest the need for additional research on the influence of aging on HPA axis function in mood and anxiety disorders.

Face processing biases in social anxiety: An electrophysiological study

Studies of information processing biases in social anxiety suggest abnormal processing of negative and positive social stimuli. To further investigate these biases, behavioral performance and event-related brain potentials (ERPs) were measured, while high- and low-socially anxious individuals performed a modified version of the Erikson flanker task comprised of negative and positive facial expressions. While no group differences emerged on behavioral measures, ERP results revealed the presence of a negative face bias in socially anxious subjects as indexed by the parietally maximal attention- and memory-related P3/late positive potential. Additionally, non-anxious subjects evidenced the presence of a positive face bias as reflected in the centrally maximal early attention- and emotion-modulated P2 and the frontally maximal response monitoring-related correct response negativity. These results demonstrate the sensitivity of different processing stages to different biases in high- versus low-socially anxious individuals that may prove important in advancing models of anxious pathology.

Emotional irritation before mental stress is associated with enhanced peripheral norepinephrine

Research suggests equivocal findings on associations of catecholamines and mood. Our study investigated the associations of emotional state, blood pressure and catecholamines in 55 healthy males undergoing mental stress. We especially checked the reported link between norepinephrine (NE) and emotional irritation. Blood pressure (SBP, DBP) and heart rate (HR) were continuously monitored. NE and epinephrine (EPI) were measured before, after, and 20 minutes after stress. Participants were divided into irritated versus non-irritated and anxious versus non-anxious subjects by median split on their baseline questionnaires. The task elicited significant cardiovascular, hormonal, and psychological stress responses. NE levels were significantly correlated with irritation before stress. Irritated subjects showed significantly higher DBP and NE than non-irritated subjects. The higher NE and DBP levels in the irritated participants suggest detrimental psycho-physiological interrelations promoting the development of stress-mediated cardiovascular diseases. Heightened emotional irritation before stress may be regarded as a psychological risk factor.

Neurophysiologic and Long-Term Effects of Clinical Hypnosis in Oral and Maxillofacial Treatment — A Comparative Interdisciplinary Clinical Study

This prospective comparative clinical study evaluated the effectiveness of clinical hypnosis and its long-term effect in oral and maxillofacial treatment. A total of 45 highly anxious and nonanxious subjects were evaluated by subjective experience and objective parameters. Parameters were EEG, ECG, heart rate, blood pressure, blood oxygen saturation, respiration rate, salivary cortisol concentration, and body temperature. During and subsequent to the operative treatment, hypnosis led to a significant reduction of systolic blood pressure, and respiration rate and to significant changes in the EEG. The subjective values of the parameters evaluated existing anxiety mechanisms and patterns and possible strategies to control them, whereas the objective parameters proved the effectiveness of hypnosis and its long-term effect.

Altered coordination of the neuroendocrine response during psychosocial stress in subjects with high trait anxiety

Contradicting data are available on stress responsiveness in subjects with high anxiety. In the present study we tested the hypothesis that high trait anxiety is associated with impaired coordination of the stress response, rather than global hypo- or hyper-responsiveness. The sample consisted of subjects with high ( n = 15) and with low ( n = 12) trait anxiety. Subjects with middle-range levels of anxiety were excluded from the study. After psychological characterization, the volunteers were exposed to a public speech procedure. A spectrum of neuroendocrine parameters was measured before, during and after the procedure and the results were analyzed by exploratory statistics. Psychological characterization of subjects revealed a lower preference for task-oriented but a higher one for emotion-oriented coping strategies as well as lower scores on hardiness in subjects with high trait anxiety. After the speech procedure, differences in selected mood and personality characteristics were observed, with the anxious group scoring significantly higher in scales for stress, tiredness, arousal, anxiety and depression. Factor analysis revealed that one common factor grouped blood pressure, catecholamine concentrations in blood and heart rate in non-anxious subjects, while three distinct factors separated these parameters in anxious subjects. Correlation analysis in anxious subjects showed that lower adrenocorticotropin (ACTH) and cortisol responses during stress were associated with exaggerated perception of stress and worse mental performance. Our findings indicate that subjects with high anxiety have different relationships between specific neuroendocrine parameters, subjective perception of stress and Stroop test performance.

Effect of worry on regional cerebral blood flow in nonanxious subjects

Several studies suggest that cognitive tasks attenuate activation of the limbic system by emotional stimuli. We investigated the possibility that worry would similarly inhibit the limbic system by examining its effects on regional cerebral blood flow (rCBF). Ten nonanxious volunteers underwent four scans within one session, using positron emission tomography (PET) with H 2 15O as tracer. The first two scans recorded emotionally neutral thinking induced after listening to tapes describing neutral statements. Preceding the third and fourth scans, subjects listened to the self-recorded tape describing their individual worries, were instructed to continue to worry, and were scanned 5 min later. Subjects rated themselves as more anxious during the worry scans but showed no significant heart interbeat or skin conductance changes. During worry, rCBF increases were found bilaterally in the medial fronto-orbital gyri and the right thalamus; rCBF decreases were found bilaterally in the hippocampi and amygdalae, in the right insula, the left and right inferior, middle and superior temporal gyri and the occipito-temporal gyri, the right inferior occipital gyrus and the left supramarginal gyrus. Activity of the left orbito-frontal gyrus was negatively correlated with activity of the amygdalae. The results support the hypothesis that worry-induced prefrontal activity suppresses affect-related subcortical regions.