Stress-induced social avoidance: a new model of stress-induced anxiety?

We have studied the long-term behavioral effects of a single stressor in male rats by using an approach/avoidance situation as the behavioral endpoint. A single exposure to social defeat or electric shocks was used as stressors. Behavioral testing was performed in a two-compartment cage divided by an opaque wall and connected by a short tunnel. The larger compartment contained an unfamiliar male rat that was separated from the rest of the compartment by a transparent, perforated Plexiglas wall. The subject was placed in the small compartment and allowed to explore the cage for 5 min. The test was performed on Days 1, 5, or 10 after stress application. Unstressed rats spent 90% of time in the large compartment that contained the unfamiliar male. Social defeat dramatically reduced the exploration of the large compartment, without time-related changes in this response. A mild electric shock had a similar effect that lasted more than 5 days but less than 10 days. The exploration of an empty cage was significantly less inhibited by stress than the exploration of a cage that contained the stimulus rat. The test could be applied repeatedly in the same rat, without major changes in the response. Chlordiazepoxide applied 1 h before behavioral testing abolished completely the stress-induced behavioral deficit. We suggest that the model can be used for studying the effects of various compounds on stress-induced anxiety.     

Obesity and health‐related quality of life: Does social support moderate existing associations?

Objectives Obesity has been shown to be negatively related to physical health‐related quality of life (HQOL) much more strongly than mental HQOL. This is remarkable given findings on obesity‐related social stigmata and associations with depression. Considering obesity as a stressor, this study tests for a moderating role of social support for obesity/HQOL associations among women and men. Design Data come from N=2,732 participants aged 35–74 years in a 2004–2005 general population survey in the Augsburg region, Germany. Methods Body weight and height were assessed by anthropometric measurements (classified by body mass index using WHO standards), social support by the Social Support Questionnaire 14‐item Short‐Form (F‐SozU‐K14) and HQOL by the 12‐item Short‐Form Health Survey (SF‐12). In multiple regression and general linear models, age, education, family status, health insurance, and place of residence were adjusted for. Results Among both genders, obesity was associated with reduced physical but not mental HQOL. Among men reporting strong social support, physical HQOL was impaired neither in the moderately nor the severely obese group (compared with normal weight), while it was given less social support. Among women, poor physical HQOL was associated with obesity regardless of social support. Conclusions In this adult population sample, no association was found for obesity with mental HQOL. In contrast, a negative association with physical HQOL exists for all subgroups except men with strong social support, indicating that social support buffers obesity‐related impairments in physical HQOL in men but not in women. This suggests that obese women and men with strong social support represent distinct populations, with possible implications for obesity care.     

Can children with autistic spectrum disorders perceive affect in music? An experimental investigation

BACKGROUND: Children with autistic spectrum disorders typically show impairments in processing affective information within social and interpersonal domains. It has yet to be established whether such difficulties persist in the area of music; a domain which is characteristically rich in emotional content. METHODS: Fourteen children with autism and Asperger syndrome and their age and intelligence matched controls were tested for their ability to identify the affective connotations of melodies in the major or minor musical mode. They were required to match musical fragments with schematic representations of happy and sad faces. RESULTS: The groups did not differ in their ability to ascribe the musical examples to the two affective categories. CONCLUSIONS: In contrast to their performance within social and interpersonal domains, children with autistic disorders showed no deficits in processing affect in musical stimuli.     

Does the level of LDL cholesterol moderate a relationship between DRD4 and novelty seeking?

This study examined the role of low density lipoprotein (LDL) cholesterol level in the association between Dopamine D4 receptor (DRD4) polymorphism and temperament dimension novelty seeking. From the on-going population based study of "Cardiovascular Risk in Young Finns", 78 men and women responded to the novelty seeking scale of the temperament and character inventory [Archives of General Psychiatry 44 (1987) 573] and were apolipoprotein E (apoE) and DRD4 genotyped. DRD4 polymorphism was related to disorderliness, a component of novelty seeking, in subjects with high LDL cholesterol level but not in subjects with low LDL cholesterol level. This finding did not change after adjustment for apoE polymorphism. Our findings suggest that the genetic determination of temperament may be dependent on biological factors, such as LDL cholesterol.     

Does mindfulness improve outcomes in patients with chronic pain? Systematic review and meta-analysis

Background

Chronic pain and its associated distress and disability are common reasons for seeking medical help. Patients with chronic pain use primary healthcare services five times more than the rest of the population. Mindfulness has become an increasingly popular self-management technique.

Aim

To assess the effectiveness of mindfulness-based interventions for patients with chronic pain.

Design and setting

Systematic review and meta-analysis including randomised controlled trials of mindfulness-based interventions for chronic pain. There was no restriction to study site or setting.

Method

The databases MEDLINE^®, Embase, AMED, CINAHL, PsycINFO, and Index to Theses were searched. Titles, abstracts, and full texts were screened iteratively against inclusion criteria of: randomised controlled trials of mindfulness-based intervention; patients with non-malignant chronic pain; and economic, clinical, or humanistic outcome reported. Included studies were assessed with the Yates Quality Rating Scale. Meta-analysis was conducted.

Results

Eleven studies were included. Chronic pain conditions included: fibromyalgia, rheumatoid arthritis, chronic musculoskeletal pain, failed back surgery syndrome, and mixed aetiology. Papers were of mixed methodological quality. Main outcomes reported were pain intensity, depression, physical functioning, quality of life, pain acceptance, and mindfulness. Economic outcomes were rarely reported. Meta-analysis effect sizes for clinical outcomes ranged from 0.12 (95% confidence interval [CI] = −0.05 to 0.30) (depression) to 1.32 (95% CI = −1.19 to 3.82) (sleep quality), and for humanistic outcomes 0.03 (95% CI = −0.66 to 0.72) (mindfulness) to 1.58 (95% CI = −0.57 to 3.74) (pain acceptance). Studies with active, compared with inactive, control groups showed smaller effects.

Conclusion

There is limited evidence for effectiveness of mindfulness-based interventions for patients with chronic pain. Better-quality studies are required.     

Does social anxiety predict rumination and co-rumination among adolescents?

Social anxiety in adolescence is manifested by anxiety about and avoidance of social interactions. The present study examined whether social anxiety predicts higher levels of both rumination and co-rumination over time. Rumination and co-rumination were studied as possible outcomes because the cognitive content of these processes often involves interpersonal concerns. A three-wave longitudinal study of 575 adolescents (aged 13-16 years old) was conducted over 6 months. Adolescent girls reported higher levels of social anxiety, rumination, and co-rumination than boys. Structural equation modelling analysis showed that social anxiety directly predicted higher levels of rumination and indirectly predicted higher levels of co-rumination over time. A gender difference was noted in that these relationships were more robust for girls than for boys.     

Does action planning moderate the intention-habit interaction in the exercise domain? A three-way interaction analysis investigation

Both habit strength and action planning have been found to moderate the intention-exercise behaviour relationship, but no research exists that has investigated how habit strength and action planning simultaneously influence this relationship. The present study was designed to explore this issue in a prospective sample of undergraduate students (N = 415): action planning, habit strength, intention, attitudes, subjective norms and perceived behavioural control were assessed at baseline and exercise behaviour was assessed 2 weeks later. Both habit strength and action planning moderated the intention-exercise relationship, with stronger relationship at higher levels of planning or habit strength. Decomposing a significant action planning × habit strength × intention interaction showed that the strength of the intention-exercise relationship progressed linearly through levels of action planning and habit strength. These novel results show that action planning strengthens the intention-habit strength interaction in the exercise domain: exercise interventions should therefore focus on simultaneously bolstering action planning and habit strength.     

Does age play a role in the structure of anxiety and depression in children and youths? An investigation of the tripartite model in three age cohorts

Although previous studies provide some support for a tripartite model of relations between anxiety and depression in children there is evidence to suggest that anxiety and depression may be increasingly differentiated over development. Using a confirmatory factor analytic strategy with rationally selected item sets from the Revised Children's Manifest Anxiety Scale and the Children's Depression Inventory, the current study sought to test unitary, dual, and tripartite models for anxiety and depression in a cross-sectional design using 3 narrow-band age cohorts of nonreferred children and youths. The results found little evidence of increasing differentiation. All models provided a moderate fit to the data, with some evidence that a correlated 3-factor model was the preferred model in all age cohorts. Further research is required to explore the discriminant validity and clinical utility of the tripartite dimensions in childhood populations.     

Do clinicians follow a risk-sensitive model of capacity-determination? An experimental video survey

The authors asked whether clinicians use a risk-sensitive model for decisional-capacity determinations; that is, whether a higher degree of capacity was required in higher-risk situations. The respondents were randomly assigned to view a videotaped "capacity" interview of a medication-randomized clinical trial scenario (N=52) or a neurosurgical clinical trial scenario (N=47). A significant scenario effect was mediated by the respondents' perception of scenario-specific risk. Respondents showed considerable disagreement within each scenario that was not explained by clinician-specific factors. Thus, clinicians, in fact, use the normative risk-sensitive model for capacity, but there remains considerable unexplained variability in their judgments.     

DoesChlamydia trachomatisMoPn enter a microbiologically-inapparent state during experimental infection of the mouse genital tract?

Microbiologically-inapparent chlamydial infection may contribute towards the immunopathogenesis of these diseases. Although morphologically and physiologically aberrant non-cultivable chlamydiae can be induced reversibly in cell culture, evidence for these forms in infections of animals and humans is indirect. A mouse model of salpingitis caused by the mouse pneumonitis biovar ofChlamydia trachomatis(MoPn) was used to determine the existence of non-cultivable organismsin vivo. Following intravaginal inoculation, mice yielded high chlamydial counts for 7–14 days, with a decline in culture-positivity by 21–28 days. A significant elevation of IFNγproduction in infected tissues was measured for 21 days and, from 28–70 days, all mice were culture-negative and developed characteristic hydrosalpinges. MoPn was detected by PCR in vaginal swabs of 80% and 69% respectively of culture-negative animals at 21 and 28 days. In a second study, 100%, 63% and 50% of culture-negative genital tissue homogenates were PCR-positive at 21, 28 and 42 days. Immunosuppression with either cyclophosphamide or hydrocortisone failed to regenerate cultivable chlamydiae. Tissues were disrupted by homogenization and inoculated intranasally to MF1 mice which are extremely susceptible to MoPn, but all culture-negative specimens were non-infectious. The significance of the PCR-positive culture-negative specimens requires further investigation, since these may represent a non-cultivable state in the deeper tissues of the mouse genital tract which may be beyond the reach of reactivating triggers.     

Does oxidative capacity affect energy cost? An in vivo MR investigation of skeletal muscle energetics

Investigations of training effects on exercise energy cost have yielded conflicting results. The purpose of the present study was to compare quadriceps energy cost and oxidative capacity between endurance-trained and sedentary subjects during a heavy dynamic knee extension exercise. We quantified the rates of ATP turnover from oxidative and anaerobic pathways with ³¹P-MRS, and we measured simultaneously pulmonary oxygen uptake in order to assess both total ATP production [i.e., energy cost (EC)] and O₂ consumption (O₂ cost) scaled to power output. Seven sedentary (SED) and seven endurance-trained (TRA) subjects performed a dynamic standardized rest-exercise-recovery protocol at an exercise intensity corresponding to 35% of maximal voluntary contraction. We showed that during a dynamic heavy exercise, the O₂ cost and EC were similar in the SED and endurance-trained groups. For a given EC, endurance-trained subjects exhibited a higher relative mitochondrial contribution to ATP production at the muscle level (84 ± 12% in TRA and 57 ± 12% in SED; P < 0.01) whereas the anaerobic contribution was reduced (18 ± 12% in TRA and 44 ± 11% in SED; P < 0.01). Our results obtained in vivo illustrate that on the one hand the beneficial effects of endurance training are not related to any reduction in EC or O₂ cost and on the other hand that this similar EC was linked to a change regarding the contribution of anaerobic and oxidative processes to energy production, i.e., a greater aerobic energy contribution associated with a concomitant reduction of the anaerobic energy supply.     

Does edaravone (MCI- 186) act as an antioxidant and a neuroprotector in experimental traumatic brain injury?

Edaravone (MCI-186) is a novel synthetic free radical scavenger intended to have neuroprotective effect against ischemic insult. It is currently used on patients with cerebral infarction. Here, we note beneficial pharmaceutical effects of edaravone in rat experimental traumatic brain injury. Under specific experimental conditions, edaravone minimized traumatic brain injury by functioning as a synthetic antioxidant. Clinical trials testing the efficacy of edaravone are warranted.     

Does disorganised attachment lead to auditory hallucinations via dissociation? An experimental study with an analogue sample

Objectives

Auditory hallucinations (such as hearing voices) are common in clinical and non-clinical populations. Many people who hear voices also report early adversity and have an insecure attachment style. Current cognitive models suggest that dissociation mediates an association between disorganised attachment and auditory hallucinations, but this has not been tested experimentally.

Design

We recruited a non-clinical analogue sample highly predisposed to auditory hallucinations and utilised an experimental design to examine the impact of disorganised attachment imagery on hallucinatory experiences, and whether dissociation mediates an expected association.

Methods

Participants completed self-report measures of state auditory hallucinations and dissociation before and after random allocation to secure or disorganised attachment conditions.

Results

Attachment imagery did not affect auditory hallucinations. Both secure and disorganised attachment conditions increased state dissociation. Secure attachment imagery reduced paranoia, but state dissociation did not mediate this effect. An exploratory analysis found that trait dissociation fully accounted for the association between trait-disorganised attachment and hallucinatory experience while controlling for paranoia.

Conclusions

Secure attachment imagery reduces paranoia but not auditory hallucinations and the impact on paranoia is not mediated by dissociation. Secure attachment imagery may be useful in reducing fears and distress associated with voices, rather than the frequency or severity of hallucinations. Disorganised attachment may increase hallucinatory experiences for people vulnerable to dissociation. Trait dissociation should be assessed in clinical settings and addressed where indicated as a means of targeting vulnerability to distressing voices.