body image disturbance body image disturbance body image disturbance (bid) is a common symptom in patients with eating disorders and is characterized by an altered perception of one's own body. not to be confused with body dysmorphic disorder. body image disturbancespecialtypsychiatry, psychologysymptomsaltered body self-perception, body uneasiness, body dissatisfaction, body-checking behaviorcomplicationseating disordersusual onsetearly adolescencerisk factorsbody dissatisfaction, childhood neglect, childhood abusediagnostic methodedi-3, body uneasiness test, clinical diagnosis, visual size estimation task, 3d morphingdifferential diagnosisbody dysmorphic disorder, obsessive-compulsive disorderpreventionpositive body image, good self-esteem, healthy eating behaviorstreatmentpsychotherapy the onset is mainly attributed to patients with anorexia nervosa who persistently tend to subjectively discern themselves as average or overweight despite adequate, clinical grounds for a classification of being considerably or severely underweight. the symptom is an altered perception of one's body and a severe state of bodily dissatisfaction characterizing the body image disturbance. it is included among the diagnostic criteria for anorexia nervosa in dsm-5 (criterion c). the disturbance is associated with significant bodily dissatisfaction and is a source of severe distress, often persisting even after seeking treatment for an eating disorder, and is regarded as difficult to treat. thus, effective body image interventions could improve the prognosis of patients with ed, as experts have suggested. however, there is no hard evidence that current treatments for body image disturbance effectively reduce eating disorder symptoms. furthermore, pharmacotherapy is ineffective in reducing body misperception and it has been used to focus on correlated psychopathology (e.g., mood or anxiety disorders). however, to date, research and clinicians are developing new therapies such as virtual reality experiences, mirror exposure, or multisensory integration body techniques, which have shown some extent of efficacy. history the scientific study of bodily experiences began at the end of the 19th century. german physiologist hermann munk was the first to suggest the existence of a cortical representation of the body, supported by his vivisection experiments on the parietal cortex of dogs. a few years later, carl wernicke hypothesized a cortical map capable of collecting and processing sensory inputs from every point of the body. in 1905 bonnier introduced the term body schema, defining it as the mental representation of the body necessary for the brain to perceive objects near, far, or within the body itself. bonnier also described three different partial body pattern alterations, hyperschématie (french; 'an overestimation of body size'), hyposchématie ('an underestimation of body size'), and paraschématie ('a displacement of body parts including internal organs'). head and holmes in 1911 expanded the concept of a body schema, introducing the concepts of postural schema and surface schema. they described a patient who could locate the stimuli applied to her body but could not locate her hand in space. they also defined the difference between schema and image. the schema defined as an unconscious representation necessary for movement and localization in space, and the "image" as a conscious body perception. therefore, in the history of medicine, distortions in the perception of one's body have mainly occurred in patients with neurological damage or with amputated limbs and a consequence of phantom limb syndrome. in the psychiatric field, the first systematic descriptions of bodily altered perception are already present in schneider's classification of symptoms of schizophrenia in 1959. the german-american psychiatrist hilde bruch was the first physician to describe body image disturbance in eating disorders accurately. characteristics hilde bruch was the first to describe the body image disturbance in anorexia nervosa accurately. she has devoted a large part of her career to studying and treating eating disorders. hilde bruch first identified and described body image disturbance in anorexia nervosa. in her article "perceptual and conceptual disturbances in anorexia nervosa" she wrote: what is pathognomic of anorexia is not the severity of the malnutrition per se—equally severe degrees are seen in other malnourished psychiatric patients—but rather the distortion of body image associated with it: the absence of concern about emaciation, even when advanced, and the vigor and stubbornness with which the often gruesome appearance is defended as normal and right, not too thin, and as the only possible security against the dreaded fate of becoming fat.— hilde bruch, perceptual and conceptual disturbances in anorexia nervosa, psychosomatic medicine, 1962 body image disturbance is not specific to anorexia nervosa, as it is sometimes present in other eating disorders such as bulimia nervosa and binge eating disorder. studies published in 2019 on cortex have shown that it is possible to observe alterations in the perception of one's body in healthy subjects. a slightly altered perception of the body is a normal part of everyone's life and manifests itself more intensely in more vulnerable individuals (e.g., patients with eating disorders). commonly, body image disturbance is confused with body dysmorphic disorder, an obsessive-compulsive disorder with which it shares some features. body image disturbance is a multifaceted construct including both perceptual and attitudinal issues. some of the more common signs are: altered body size estimation and altered perception of the body and its shapes; mental images of one's body appearing distorted or overweight; frequently third-person mental view of one's body; negative body-related thoughts; frequent body-checking behaviors; frequent comparisons between one's own body and the bodies of others; emotions of anxiety, shame, and contempt for one's body. clinically speaking, a growing body of research suggests that body image disturbance plays a significant role in the onset, maintenance, and relapse of anorexia nervosa, as previously suggested by bruch in 1962. however, despite increasing evidence, a review by glashouwer in 2019 stated that the available empirical data are still insufficient and "provide no basis to answer the question whether body image disturbance is a (causal) risk factor for anorexia nervosa". as suggested by the author, this lack of evidence is partly related to terminology problems used in the body image field. in binge eating disorder body image disorder is a characteristic symptom of anorexia nervosa and bulimia nervosa. in both of these disorders, an excessive focus on body shapes and sizes made the body image disturbance easier to identify, to describe, and study. much less is known about the disorder in patients with binge eating disorder. as early as 1993, spitzer compared obese individuals with and without binge eating disorder (bed) and found that those with bed were more frequently concerned about body shape and weight. additionally, binge eating disorder patients show more significant concerns about weight and body shape, more intense body dissatisfaction, and more frequent avoidance and body checking behaviors. on the other hand, few studies have investigated the altered body perception in patients with binge eating disorder and the results are conflicting. some patients tend to overestimate their body shapes, in others, they do not. in some cases the perceptual disturbance manifests itself in a paradoxical way, with an underestimation of the real body shapes and sizes. this difference suggests different phenotypes in binge spectrum; hence, a perceptual disturbance can be considered an aggravation of the binge eating disorder, as claimed by lewer and colleagues in 2017. epidemiology there are no reliable epidemiological data in the literature for body image disturbance. there are numerous challenges with diagnosis, the most relevant of which is the unclear definition of body image disturbance within official diagnostic manuals such as the dsm and the icd, which prevents its identification in the population. further, there are challenges with diagnostic tools, both for recognition and screening. the altered perception of the body can only be measured through behavioral tasks delivered individually (see section below). it cannot be measured with questionnaires, or other tools typically used for broad-spectrum investigations. as it is not always present in eating disorders, its prevalence is not comparable to that of anorexia nervosa, bulimia nervosa, and binge eating disorder, and cannot be inferred from them. a negative body image may also be present in other psychiatric conditions such as ptsd, major depression, and body dysmorphic disorder. taken together this data suggests the possible presence of perceptual disturbances in other pathological conditions not directly related to eating disorders. therefore, the presence of a body image disturbance in other psychiatric diseases remains speculation, not yet supported by sufficient literature data, as suggested by scheffers. definition dsm-5 different labels are used in research and clinical settings to describe body image disturbance, generating terminological confusion. among the most used terms are body image discrepancy, body image self-discrepancy, body image distortion, disturbed body image, disturbances in body estimations, body image disturbance, and negative body image. sometimes, the term body dissatisfaction is also used to refer to body image disturbance indiscriminately. moreover, the dsm-5 defines this symptom vaguely: "a disturbance in the way one's body weight or shape is experienced". the lack of a clear definition is problematic from both a clinical and basic research point of view. multidimensional despite the terminological problems, during the early 2000s numerous scholars agree that body image disturbance is a multidimensional symptom of various components associated with body image. body image is a concept formed by the interaction of four body-related components: cognitive, affective, behavioral, and perceptual. cognitive: thoughts and beliefs about one's body and its shape; a conscious mental representation of the body affective: feelings and attitudes related to the body (e.g. bodily satisfaction/dissatisfaction). behavioral: the actions that people perform to check on, modify, or hide their body parts. perceptual: how the mind senses and perceives the body; it includes proprioceptive, interoceptive, tactile, and visual self-perception. in people with body image disturbance all of these components are altered at the same time. in 2021, artoni et al proposed a clearer definition of body image disturbance as part of a study in eating and weight disorders. the authors suggested using the term bodily dissatisfaction when there are alterations in either the affective, cognitive, or behavioral components of body image and strictly reserving the term body image disturbance only when all four components are altered, including perception. in short, they define body image disturbance as the presence of an altered perception of the shape and weight of one's body, which aggravates body dissatisfaction. the term is consistent with the dsm-5 description "a disturbance in the way weight and body shapes are experienced" and it is therefore "preferable to others". components cognitive patients with body image disturbance exhibit an alteration in how the body's image is stored in their memory—the conscious representation of their bodies. this representation is from a third-person, perspective, more precisely an allocentric representation of the body. this representation is evoked in self-image tasks, such as comparing one's body with others or drawing one's body shapes. however, patients with anorexia nervosa and bulimia nervosa frequently perceive their body as larger than it is in reality. patients with anorexia nervosa have negative thoughts about their body, such as "i'm too fat," "i'm ugly," and other negative body-related thoughts. in some cases, however, the ideal internalized body is indicative of unhealthy thinness (e.g., a body without female shapes or one that communicates suffering). an unhealthy body shape could be a critical maintenance factor, generating more attention from family members, reducing the requests and expectations of others, and minimizing sexual attractiveness (especially in patients with sexual trauma). affective affective components of body image are the feelings and emotions experienced towards one's body. body dissatisfaction is frequently present in those with body image disturbance, sometimes related to anxiety and shame when the body is exposed or gazed at in a mirror. in some cases, anger and feelings of aggression towards one's body are reported. fear is associated with thoughts of getting fat. congruent with the self-objectification theory, people with body image disturbance frequently experience the body only as an object to be modified rather than as a subject to take care of. behavioral the behavioral component of body image disturbance includes different body-checking behaviors such as repeatedly weighing during the day, spending significant time in front of the mirror or avoiding it, frequently taking selfies, checking parts of the body with hands (e.g. measuring the circumference of the wrists, arms, thighs, belly or hips). other behaviors include avoiding situations in which the body is exposed (for example, when swimming), and wearing very loose and covering clothes. more generally, avoidance of bodily sensations, particularly the interoceptive ones, is reported. perceptual in body image disturbance, several perceptual domains are altered. visual perception is the most studied, but research has found misperceptions in other sensory domains such as haptic, tactile, and