Examining the Factor Structure, Reliability, and Validity of the Disturbing Dreams and Nightmare Severity Index (DDNSI) Consequences Sub-component.

Background: The Disturbing Dreams and Nightmares Severity Index (DDNSI) is commonly used when assessing the experience of nightmares. It comprises two parts examining i) chronicity and ii) nightmare consequences. The primary aim of the present study was to explore the dimensional structure of the optional and currently unvalidated nightmare consequences component using exploratory factor analysis. Internal reliability and construct validity were also examined. A secondary aim explored the relationships between nightmare chronicity and perceived consequences with measures of anxiety, depression, stress, self-efficacy, and insomnia.Methods: A cross-sectional survey was conducted with complete data from N = 757 students from six UK-based universities. Participants completed the chronicity and consequences components of the DDNSI, alongside the Sleep Condition Indicator, Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, Perceived Stress Scale, and General Self-Efficacy Scale.Results: Two nightmare consequences factors emerged; 'Sleep-Interference' (four items; α =.848), and 'Psychosocial Well-being' (six items; α =.946). Significantly moderate correlations were observed between the two emerging factors and the nightmare chronicity component, as well as with insomnia, anxiety, depression, perceived stress, and self-efficacy. Perceived 'Sleep-Interference' (ß =-.241) was the strongest predictor of insomnia, and 'Psychosocial wellbeing' was the strongest predictor of anxiety (ß =.688) depression (ß =.804) perceived stress and lower self-efficacy.Conclusions: The perceived nightmare consequences component of the DDSNI is a multidimensional construct comprising two internally consistent and distinct, but related dimensions. The potential importance of distinguishing between types of perceived nightmare consequences and the associations with mental health outcomes in a student population is highlighted.

Homogeneity of cognitive and behavioural processes underlying the relationship between insomnia and body image disturbance.

Specific cognitive behavioural mechanisms related to selective attention, situational avoidance and physical appearance are implicated in the development and maintenance of insomnia and negative reinforcement of body image disturbances. Therefore, we examined whether these processes potentially mediate the relationship between insomnia and body image perception. N = 728 participants completed self-reported measures of sleep-associated monitoring, insomnia symptoms, body image disturbance and coping with body image challenges. Symptoms of insomnia and sleep-associated monitoring behaviour were independently related to increased reports of body image disturbance, cognitive distortions of body image, appearance fixing (i.e. altering appearance by covering, camouflaging or correcting the perceived defect), avoidance (i.e. attempt to escape or avert stressful body image situations) and reduced levels of positive rationale acceptance (i.e. acceptance of the challenging event and positive self-care or rationale self-talk about one's appearance). More crucially, sleep-related monitoring on awakening, cognitive distortion of body image and negative coping strategies related to body image (i.e. appearance fixing, avoidance, rationale acceptance) mediated the relationship between reports of body image disturbance and insomnia symptoms. The current findings expand upon previous research demonstrating consistent relationships between poor sleep and increased dissatisfaction with cutaneous features, by providing novel evidence that body image disturbances are associated with symptoms of insomnia. More crucially, we highlight the role of particular cognitive and behavioural mechanisms pertaining to sleep (i.e. selective attention for physical signs of poor sleep) and body image (i.e. avoidance and rationale acceptance) which may be targeted as part of cognitive behavioural treatments.

The Effect of Own Body Concerns on Judgments of Other Women's Body Size.

We investigated the relationships between healthy women's estimates of their own body size, their body dissatisfaction, and how they subjectively judge the transition from normal to overweight in other women's bodies (the "normal/overweight" boundary). We propose two complementary hypotheses. In the first, participants compare other women to an internalized Western "thin ideal," whose size reflects the observer's own body dissatisfaction. As dissatisfaction increases, so the size of their "thin ideal" reduces, predicting an inverse relationship between the "normal/overweight" boundary and participants' body dissatisfaction. Alternatively, participants judge the size of other women relative to the body size they believe they have. For this implicit or explicit social comparison, the participant selects a "normal/overweight" boundary that minimizes the chance of her making an upward social comparison. So, the "normal/overweight" boundary matches or is larger than her own body size. In an online study of 129 healthy women, we found that both opposing factors explain where women place the "normal/overweight" boundary. Increasing body dissatisfaction leads to slimmer judgments for the position of the "normal/overweight" boundary in the body mass index (BMI) spectrum. Whereas, increasing overestimation by the observer of their own body size shifts the "normal/overweight" boundary toward higher BMIs.

Self-disgust as a potential mechanism underlying the association between body image disturbance and suicidal thoughts and behaviours.

This study examined whether self-disgust added incremental variance to and mediated the multivariate association between measures of body image disturbance and suicidal thoughts and behaviours. We hypothesized that self-disgust would be associated with suicidal ideation above the effects of body image disturbance, and that self-disgust would mediate the relationship between body image disturbance and suicidal ideation. A total of N=728 participants completed The Body Image Disturbance Questionnaire, The Self-Disgust Scale, and the Suicidal Behaviours Questionnaire-Revised. Suicidality was significantly related to increased levels of self-disgust and body image disturbance, whereas self-disgust was associated with greater body image disturbance. Linear regression analysis showed that self-disgust was associated with suicidal thoughts and behaviours, over and above the effects of body image disturbance. Multiple mediation modelling further showed that self-disgust mediated the relationship between body image disturbance and suicidal thoughts and behaviours. Our findings highlight the role of self-disgust in the context of body image disturbance and support the notion that body image disturbance is associated with aversive self-conscious emotions. Interventions aiming to reduce the risk of suicidality in people with body image disturbance may address self-disgust and negative self-conscious emotions.

Using immersive virtual reality to modify body image.

We tested the efficacy of a training programme, delivered in virtual reality (VR), to modify the perceptual boundary between what participants classify as a fat versus a thin body. Three cohorts of 20 female volunteers with high body image concerns were recruited to two intervention groups and one control group. All participants completed a 4-day training programme in VR where they categorised a series of 3D models as either thin or fat; one intervention group was presented with the stimuli briefly, while the other group had no time limits imposed. Both intervention groups were given inflationary feedback to shift their categorisations of the stimulus models towards higher BMIs. Our results show that, compared to controls, both intervention groups shifted their categorical boundaries between Day 1 and follow-up on Day 14. Unlimited stimulus presentation times were associated with a larger training effect. Furthermore, both intervention groups experienced statistically significant reductions in their concerns about their own body shape, weight and eating habits. However, only in the group with longer stimulus presentation times were these reductions consistent with a clinically meaningful effect. These findings suggest that manipulating categorical perception in VR might provide a complementary addition to existing treatments for eating disorders.

The visual cues that drive the self-assessment of body size: Dissociation between fixation patterns and the key areas of the body for accurate judgement.

A modified version of the bubbles masking paradigm was used in three experiments to determine the key areas of the body that are used in self-estimates of body size. In this paradigm, parts of the stimuli are revealed by several randomly allocated Gaussian "windows" forcing judgements to be made based on this partial information. Over multiple trials, all potential cues are sampled, and the effectiveness of each window at predicting the judgement is determined. The modified bubbles strategy emphasises the distinction between central versus edge cues and localises the visual features used in judging one's own body size. In addition, eye-movements were measured in conjunction with the bubbles paradigm and the results mapped onto a common reference space. This shows that although observers fixate centrally on the torso, they are actually directing their visual attention to the edges of the torso to gauge body width as an index of body size. The central fixations are simply the most efficient way of positioning the eye to make this estimation. Inaccurate observers are less precise in their central fixations and do not evenly allocate their attention to both sides of the torso's edge, illustrating the importance of efficiently sampling the key information.

Distorted body image influences body schema in individuals with negative bodily attitudes.

There is now a considerable body of evidence to suggest that internal representations of the body can be meaningfully separated into at least two general levels; body image as a perceptual construct and body schema as a motor metric. However, recent studies with eating disordered individuals have suggested that there may in fact be more interaction between these two representations than first thought. We aimed to investigate how body image might act to influence body schema within a typical, healthy population. 100 healthy adult women were asked to judge the smallest gap between a pair of sliding doors that they could just pass through. We then determined whether these estimates were sufficient to predict the size of the smallest gap that they could actually pass through, or whether perceptual and attitudinal body image information was required in order to make these predictions. It was found that perceptual body image did indeed mediate performance on the egocentric (but not allocentric) motor imagery affordance task, but only for those individuals with raised body image concerns and low self-esteem; body schema was influenced by both the perceptual and attitudinal components of body image in those with more negative bodily attitudes. Furthermore, disparities between perceived versus actual size were associated with body parts that had larger variations in adipose/muscle-dependent circumference. We therefore suggest that it may be the affective salience of a distorted body representation that mediates the degree to which it is incorporated into the current body state.