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Peripheral inflammation is closely related to the pathogenesis of sickness behaviors and psychiatric disorders such as anxiety and depression. The circumventricular organs (CVOs) are important brain sites to perceive peripheral inflammatory signals, but few studies have reported their role in inflammation-induced anxiety or depression. Using a mouse model of lipopolysaccharide (LPS)-induced inflammation, we identified a previously unreported role of the subfornical organ (SFO), one of the CVOs, in combating inflammation-induced anxiety. LPS treatment induced anxiety-like and sickness behaviors in mice. Although both the SFO and the organum vasculosum of the lamina terminalis (a CVO) neurons were activated after LPS treatment, only manipulating SFO neurons modulated LPS-induced anxiety-like behaviors. Activating or inhibiting SFO neurons alleviated or aggravated LPS-induced anxiety-like behaviors. In addition, SFO exerted this effect through glutamatergic projections to the bed nucleus of the stria terminalis. Manipulating SFO neurons did not affect LPS-induced sickness behaviors. Thus, we uncovered an active role of SFO neurons in counteracting peripheral inflammation-induced anxiety.

Objectives: Approximately one in five adults experiences chronic pain, often in co-occurrence with depression, insomnia, anxiety, and lower self-rated health. Elevated levels of cytokines, e.g. tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), interleukin 8 (IL-8), and interleukin 10 (IL-10), have been identified in patients with chronic pain. Depression, insufficient sleep, poor self-rated health, and pain intensity have also been associated with inflammatory biomarkers. This study aimed to investigate the interrelationships between inflammatory biomarkers and depression, insomnia, anxiety, self-rated health, sickness behavior, and pain intensity in patients with chronic pain., Methods: Self-report questionnaires and blood samples analyzed for plasma levels of inflammatory biomarkers were collected from 80 adult patients with chronic pain. Associations between inflammatory biomarkers (TNF-α, IL-6, IL-8, IL-10, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR)) and depression, insomnia, anxiety, self-rated health, sickness behavior, and pain intensity, were analyzed using bivariate Spearman rank correlation coefficients and regression analyses., Results: Participants were mainly women (72.5 %), with a mean age of 50.8 years, and a reported mean pain duration of 16.7 years. There were significant correlations between insomnia and CRP (r s =.26, p <.05); sex and ESR (r s =.29, p <.05); age and IL-6 (r s =.29, p <.05) and IL-8 (r s =.30, p <.05); BMI and IL-6 (r s =.50, p <.001), CRP (r s =.63, p <.001) and ESR (r s =.42, p <.001). Ratings of depression were positively and significantly related to ratings of sickness behavior and anxiety (β =.32 and β =.40, respectively), explaining 49 % of the total variance in depression ratings. Insomnia was positively and significantly related to sickness behavior (β =.37) explaining 31 % of the total variance in insomnia ratings. Inflammatory biomarkers, however, did not contribute significantly to the models., Conclusions: Participants reported high levels of symptoms, yet the associations between these ratings and the inflammatory biomarkers were either absent or weak. Also, despite high levels of self-reported sickness behavior, overall the inflammatory status remained within the normal range. Ratings of sickness behavior contributed more than inflammatory markers in explaining ratings of depression and insomnia. The present results point to the complexity of chronic pain, and the challenges of identifying biomarkers that explain symptomatology., Competing Interests: Declaration of Competing Interest No conflict., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The use of endotoxin, such as lipopolysaccharide (LPS) as a model of sickness behavior, has attracted recent attention. To objectively investigate sickness behavior along with its pain-like behaviors in LPS-treated mice, the behavioral measurement requires accurate methods, which reflects clinical relevance. While reflexive pain response tests have been used for decades for pain assessment, its accuracy and clinical relevance remain problematic. Hence, we used automated home-cage monitoring LABORAS to evaluate spontaneous locomotive behaviors in LPS-induced mice. LPS-treated mice displayed sickness behaviors including pain-like behaviors in automated home-cage monitoring characterized by decreased mobile behaviors (climbing, locomotion, rearing) and increased immobility compared to that of the control group in both short- and long-term locomotive assessments. Here, in short-term measurement, both in the open-field test and automated home-cage monitoring, mice demonstrated impaired locomotive behaviors. We also assessed 24 h long-term locomotor activity in the home-cage system, which profiled the diurnal behaviors of LPS-stimulated mice. The results demonstrated significant behavioral impairment in LPS-stimulated mice compared to the control mice in both light and dark phases. However, the difference is more evident in the dark phase compared to the light phase owing to the nocturnal activity of mice. In addition, the administration of indomethacin as a pharmacological intervention improved sickness behaviors in the open-field test as well as automated home-cage monitoring, confirming that automated home-cage monitoring could be potentially useful in pharmacological screening. Together, our results demonstrate that automated home-cage monitoring could be a feasible alternative to conventional methods, such as the open-field test and combining several behavioral assessments may provide a better understanding of sickness behavior and pain-like behaviors in LPS-treated mice., Competing Interests: The authors have declared that no competing interests exist.

Exposure to light at night (LAN) can disrupt the circadian system, thereby altering neuroimmune reactivity and related behavior. Increased exposure to LAN affects people of all ages - and could have particularly detrimental effects during early-life and adolescence. Despite this, most research on the behavioral and physiological effects of LAN has been conducted in adult animals. Here we evaluated the effects of dim LAN during critical developmental windows on adulthood neuroimmune function and affective/sickness behaviors. Male and female C57BL/6 J mice were exposed to dim LAN [12:12 light (150 lx)/dim (15 lx) cycle] during early life (PND10-24) or adolescence (PND30-44) [control: 12:12 light (150 lx)/dark (0 lx) cycle]. Behaviors were assessed during juvenile (PND 42-44) and adult (PND60) periods. Contrary to our hypothesis, juvenile mice that were exposed to dim LAN did not exhibit changes in anxiety- or depressive-like behaviors. By adulthood, adolescent LAN-exposed female mice showed a modest anxiety-like phenotype in one behavioral task but not another. Adolescent LAN exposure also induced depressive-like behavior in a forced swim task in adulthood in both male and female mice. Additionally, developmental LAN exacerbated the hippocampal cytokine response (IL-1β) following peripheral LPS in female, but not male mice. These results suggest female mice may be more susceptible to developmental LAN than male mice: LAN female mice had a modest anxiety-like phenotype in adulthood, and upon LPS challenge, higher hippocampal IL-1β expression. Taken together, developmental LAN exposure in mice promotes a modest increase in susceptibility to anxiety- and depressive-like symptoms., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: As the fight against the COVID-19 epidemic continues, medical workers may have allostatic load., Objective: During the reopening of society, medical and nonmedical workers were compared in terms of allostatic load., Methods: An online study was performed; 3,590 Chinese subjects were analyzed. Socio-demographic variables, allostatic load, stress, abnormal illness behavior, global well-being, mental status, and social support were assessed., Results: There was no difference in allostatic load in medical workers compared to nonmedical workers (15.8 vs. 17.8%; p = 0.22). Multivariate conditional logistic regression revealed that anxiety (OR = 1.24; 95% CI 1.18-1.31; p < 0.01), depression (OR = 1.23; 95% CI 1.17-1.29; p < 0.01), somatization (OR = 1.20; 95% CI 1.14-1.25; p < 0.01), hostility (OR = 1.24; 95% CI 1.18-1.30; p < 0.01), and abnormal illness behavior (OR = 1.49; 95% CI 1.34-1.66; p < 0.01) were positively associated with allostatic load, while objective support (OR = 0.84; 95% CI 0.78-0.89; p < 0.01), subjective support (OR = 0.84; 95% CI 0.80-0.88; p < 0.01), utilization of support (OR = 0.80; 95% CI 0.72-0.88; p < 0.01), social support (OR = 0.90; 95% CI 0.87-0.93; p < 0.01), and global well-being (OR = 0.30; 95% CI 0.22-0.41; p < 0.01) were negatively associated., Conclusions: In the post-COVID-19 epidemic time, medical and nonmedical workers had similar allostatic load. Psychological distress and abnormal illness behavior were risk factors for it, while social support could relieve it., (© 2020 The Author(s) Published by S. Karger AG, Basel.)

Objectives: It is well known that mental health problems can recur even after effective treatment, leading to an understandable fear of illness recurrence (FIR) and mental health anxiety (MHA). These may themselves contribute to the process of relapse. This study aims to examine whether people recovering from psychosis have greater FIR than those recovering from common mental health problems or healthy controls. The study also hypothesized that there will be a relationship between FIR and MHA and that both these constructs will be associated with maladaptive coping behaviours. Finally, the relationship between mental defeat with FIR and psychological distress (anxiety and depression) will be examined., Method: A cross-sectional questionnaire design was employed. Thirty-nine participants in recovery from psychosis, eighty-two in recovery from other mental health difficulties, and sixty-one healthy controls aged 18-73 were recruited from NHS services and via social media. Self-report questionnaires measured mental defeat, mental health anxiety, fear of illness recurrence, maladaptive coping behaviours, and psychological distress., Results: Those recovering from psychosis were found to more negatively evaluate the likely consequences of relapse than those recovering from common mental health problems or healthy controls. However, the levels of FIR in common mental health problems were also significantly elevated when compared to healthy controls. There were no other differences between these groups (in terms of mental defeat, anxiety, depression, social functioning, and maladaptive coping behaviours). The hypothesized relationship between FIR and MHA was also found, and both were associated with maladaptive coping behaviours. Mental defeat was associated with FIR and psychological distress (anxiety and depression)., Conclusions: This study found that those with psychosis experienced higher FIR than those with common mental health problems. Furthermore, people defining themselves as in recovery are worried about relapse and the extent of this is linked to mental health anxiety. Given that such responses may contribute to actual relapse, it is important that these issues are better understood and interventions developed to ameliorate them., Practitioner Points: Following recovery, fear of relapse may be particularly high in those with experience of psychosis; it is also present in those with common mental health problems The importance of this observation lies in the issue that anxiety about relapse may initiate a self-fulfilling process, with increased anxiety worsening symptoms and vice versa. Cognitive-behavioural therapy for health anxiety may be beneficial to those experiencing high levels of mental health anxiety. Cognitions related to relapse need to be explored and addressed both in further research and, when clearly identified, may be a target during relapse-prevention planning., (© 2020 The Authors. British Journal of Clinical Psychology published by John Wiley & Sons Ltd on behalf of British Psychological Society.)

According to the cognitive-behavioral model, illness anxiety is developed and maintained through biased processing of health-threatening information and maladaptive responses to such information., Objective: This study is a systematic review of research that attempted to validate central tenets of the cognitive-behavioral model regarding etiological and maintenance mechanisms in illness anxiety., Methods: Sixty-two studies, including correlational and experimental designs, were identified through a systematic search of databases and were evaluated for their quality., Results: Outcomes were synthesized following a qualitative thematic approach under categories of theoretically driven mechanisms derived from the cognitive-behavioral model: attention, memory and interpretation biases, perceived awareness and inaccuracy in perception of somatic sensations, negativity bias, emotion dysregulation, and behavioral avoidance., Conclusions: Findings partly support the cognitive-behavioral model, but several of its hypothetical mechanisms only receive weak support due to the scarcity of relevant studies. Directions for future research are suggested based on identified gaps in the existing literature., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: To determine whether depressed or anxious patients experience greater affective change than mentally healthy individuals following influenza vaccination., Methods: Participants (n=112) completed the Positive and Negative Affect Schedule (PANAS) before influenza vaccination and 1-2days post-vaccination (M=32.3h). Pre- and post-vaccination PANAS scores were compared using two-tailed, paired-samples t-tests. Change in positive affect between participants with depression or anxiety and those without was compared using two-way ANOVA. Follow up positive affect was further examined using multiple linear regression., Results: Positive affect decreased following vaccination (M=2.18, 95% CI [1.07, 3.29], t(111)=3.89, p<0.001) for all participants and was more pronounced for those with anxiety or depression (F(1, 110)=7.51, p=0.009). Similarly, predicted follow up affect score was higher for those without a mental health conditions (β=3.67, 95% CI [1.18, 6.16], t(103)=2.92, p=0.004)., Conclusions: These data suggest that influenza vaccine has a greater effect on affect in patients with depression and anxiety than in mentally healthy individuals. This effect was focused on positive affect, suggesting that influenza vaccine induced inflammation may be best suited to examine alterations in positive affect and positive valence systems., (Copyright © 2017 Elsevier Inc. All rights reserved.)

A psychosomatic approach to the basic screening of distress for patient care in hospitals and other health services is presented. The aims of this study were to verify association between: (1) medical illnesses and distress; (2) patients' needs and distress; (3) type of illness and patients' needs; (4) patients' needs and sense of coherence. One hundred and eighty-nine patients (78 F and 111 M, average age 65 years±8.43) were assessed by self-report questionnaires. We found that higher anxiety and/or depression levels were associated with urogenital (p=0.026), rheumatologic (p=0.006), oncological (p=0.011), neurological (p=0.026) and respiratory (p=0.013) illnesses. Higher distress scoring was associated with rheumatologic illnesses (p=0.024) and illnesses of the liver and digestive system (p=0.037) while a higher severity of distress was associated with oncological illnesses (p=0.011). Depression/anxiety were associated with the need to speak to a psychologist (p=0.050), to a spiritual advisor (p=0.009), to be more reassured by relatives (p=0.017), to feel less abandoned (p=0.036). Only low sense of coherence was associated with the need for greater dialogue with physicians (p=0.012), the need to participate less in treatment decisions (p=0.041), the need to feel less left to one's own devices (p=0.023). Several needs are associated with medical illnesses. In conclusion, these results indicate that early psychological screening could be important to avoid worse or chronic distress., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Interleukin-1 (IL-1) is a key pro-inflammatory cytokine, produced predominantly by peripheral immune cells but also by glia and some neuronal populations within the brain. Its signalling is mediated via the binding of IL-1α or IL-1β to the interleukin-1 type one receptor (IL-1RI). IL-1 plays a key role in inflammation-induced sickness behaviour, resulting in depressed locomotor activity, decreased exploration, reduced food and water intake and acute cognitive deficits. Conversely, IL-1 has also been suggested to facilitate hippocampal-dependent learning and memory: IL-1RI(-/-) mice have been reported to show deficits on tasks of visuospatial learning and memory. We sought to investigate whether there is a generalised hippocampal deficit in IL-1RI(-/-) animals. Therefore, in the current study we compared wildtype (WT) mice to IL-1RI(-/-) mice using a variety of hippocampal-dependent learning and memory tasks, as well as tests of anxiety and locomotor activity. We found no difference in performance of the IL-1RI(-/-) mice compared to WT mice in a T-maze working memory task. In addition, the IL-1RI(-/-) mice showed normal learning in various spatial reference memory tasks including the Y-maze and Morris mater maze, although there was a subtle deficit in choice behaviour in a spatial discrimination, beacon watermaze task. IL-1RI(-/-) mice also showed normal memory for visuospatial context in the contextual fear conditioning paradigm. In the open field, IL-1RI(-/-) mice showed a significant increase in distance travelled and rearing behaviour compared to the WT mice and in the elevated plus-maze spent more time in the open arms than did the WT animals. The data suggest that, contrary to prior studies, IL-1RI(-/-) mice are not robustly impaired on hippocampal-dependent memory and learning but do display open field hyperactivity and decreased anxiety compared to WT mice. The results argue for a careful evaluation of the roles of endogenous IL-1 in hippocampal and limbic system function.

In this study we characterised the ability of the viral mimetic poly I:C to induce a neuroinflammatory response and induce symptoms of depression and anxiety in rats. Furthermore, the ability of poly I:C to deplete central tryptophan and serotonin via induction of indolamine 2,3 dioxygenase (IDO), and also the ability of poly I:C to impact upon expression of the neurotrophin BDNF and its receptor TrkB were examined as potential mechanisms to link inflammation to depression. Poly I:C induced a neuroinflammatory response characterised by increased expression of IL-1β, IL-6, TNF-α and CD11b in frontal cortex and hippocampus. In the first 24h following poly I:C administration rats displayed sickness behaviour characterised by reduced locomotor activity and weight gain. Anhedonia measured using the saccharin preference test was used as an indicator of depressive behaviour, and poly I:C induced depressive behaviour that persisted for up to 72h following administration. Anxiety was measured using the open field test and anxious behaviour was observed 24h following poly I:C, a time-point when sickness behaviour had resolved. These behavioural changes were accompanied by decreased expression of BDNF and TrkB in hippocampus and frontal cortex. In addition, poly I:C increased central IDO expression and increased concentrations of tryptophan, and its metabolite kynurenine. However this activation of the kynurenine pathway did not result in reduced central serotonin concentrations. These findings suggest that depressive and anxiety-like behaviours elicited by poly I:C are associated with a reduction in BDNF signalling, and activation of the kynurenine pathway, but not a reduction in serotonin., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background: Many older adults have at least one chronic disease and experience greater health problems than young adults. However, little is known about factors other than health that account for health anxiety (HA) among older adults. The overall objective of the present study was to develop a better understanding of HA among older and young adults., Methods: We examined how anxiety-related constructs (anxiety sensitivity, intolerance of uncertainty, anxiety control, and emotion regulation) predict two core components of HA described in the cognitive-behavioral model of HA (illness likelihood and negative consequences) in older and young adults. We also examined the extent to which the predictor variables differentially account for HA in both age groups. Older and young adult participants completed several self-report surveys., Results: Young adults reported higher levels of HA than older adults. Anxiety sensitivity and reappraisal predicted illness likelihood for older and young adults. Intolerance of uncertainty predicted negative consequences in both age groups. Anxiety sensitivity predicted negative consequences for older adults only. Anxiety control did not predict illness likelihood or negative consequences for either age group., Conclusions: Results suggest that anxiety sensitivity and intolerance of uncertainty may predispose older and young adults to HA, which is influenced by reappraisal. Implications for the cognitive-behavioral model of HA in both age groups are discussed.

Insecure attachment has been hypothesized to be an important factor for understanding the experience of pain. Considering the Attachment-Diathesis Model of Chronic Pain developed by Meredith, Ownsworth, and Strong (2008), this cross-sectional study examines the relationship between attachment style, pain appraisal, and illness behavior. Two hundred healthy women recruited from community contexts completed a battery of self-report measures including the Short-form McGill Pain Questionnaire, Pain Catastrophizing Scale, Pain Anxiety Symptoms Scale-20, Pain Vigilance and Awareness Questionnaire, Illness Attitude Scales, Beck Anxiety Inventory, Beck Depression Inventory, and the Experiences in Close Relationships Questionnaire-Revised. The results showed that attachment anxiety was significantly correlated with pain catastrophizing, pain-related fear, depression, and illness behavior. However, attachment anxiety and avoidance were not associated with pain intensity. Attachment anxiety moderated the relationship between pain catastrophizing and illness behavior, and between pain hypervigilance and illness behavior. Pain catastrophizing and pain-related fear partially mediated the effect of attachment anxiety on illness behavior. The findings highlight potential contributions of attachment style and pain appraisal for explaining illness behavior. This study supports earlier reports and suggests the usefulness of assessing attachment style for early identification of people who might exhibit a high risk of dysfunctional responses to pain. Our findings also suggest that increasing people's insight about their attachment style and modifying some associated dysfunctional responses may be important in the treatment of chronic pain., (© 2011 The Authors. Scandinavian Journal of Psychology © 2011 The Scandinavian Psychological Associations.)

Recent reports indicate that exposure to some stressors, such as shipping or immune challenge with the bacterial endotoxin, lipopolysaccharide (LPS), during the peripubertal period reduces sexual receptivity in response to ovarian hormones in adulthood. We hypothesized that a peripubertal immune challenge would also disrupt the response of a non-reproductive behavior, anxiety-like behavior, to ovarian hormones in adulthood. Female C57Bl/6 mice were injected with LPS during the peripubertal period and tested for anxiety-like behavior in adulthood, following ovariectomy and ovarian hormone treatment. Treatment with estradiol followed by progesterone reduced anxiety-like behavior in control, but not LPS-treated females. We next determined if the disruptive effect of LPS on adult behavior were limited to the peripubertal period by treating mice with LPS either during this period or in adulthood. LPS treatment during the peripubertal period disrupted the anxiolytic effect of ovarian hormones, whereas treatment in adulthood did not. We further tested if this model of peripubertal immune challenge was applicable to an outbred strain of mice (CD-1). Similar to C57Bl/6 mice, LPS treatment during the peripubertal period, but not later, disrupted the anxiolytic effect of estradiol and progesterone. These data suggest that a peripubertal immune challenge disrupts the regulation of anxiety-like behavior by ovarian hormones in a manner that persists at least for weeks after the termination of the immune challenge., (Copyright © 2011 Elsevier Inc. All rights reserved.)