Eating Disorder or Disordered Eating? Non‐normative Eating Patterns in Obese Individuals

Binge eating disorder (BED) and night eating syndrome (NES) are putative eating disorders frequently seen in obese individuals. Data suggest that BED fulfills criteria for a mental disorder. Criteria for NES are evolving but at present do not require distress or functional impairment. It remains unclear whether BED and NES, as they are currently defined, are optimally useful for characterizing distinct patient subgroups. We propose that a distinction be made between “eating disorders” and “non‐normative” eating patterns without associated distress or impairment. Although non‐normative eating patterns may not be considered mental disorders, they may be very important in terms of their impact on body weight and health. More precise behavioral and metabolic characterization of subgroups with eating disorders and non‐normative eating behaviors has important implications for understanding the etiology, pathophysiology, and treatment of obesity. Ultimately, better understanding of the many pathways to increased energy intake may lead to targeted strategies for prevention of overweight and obesity in at‐risk individuals and populations.     

Classification of feeding and eating disorders: review of evidence and proposals for ICD-11

Current classification of eating disorders is failing to classify most clinical presentations; ignores continuities between child, adolescent and adult manifestations; and requires frequent changes of diagnosis to accommodate the natural course of these disorders. The classification is divorced from clinical practice, and investigators of clinical trials have felt compelled to introduce unsystematic modifications. Classification of feeding and eating disorders in ICD-11 requires substantial changes to remediate the shortcomings. We review evidence on the developmental and cross-cultural differences and continuities, course and distinctive features of feeding and eating disorders. We make the following recommendations: a) feeding and eating disorders should be merged into a single grouping with categories applicable across age groups; b) the category of anorexia nervosa should be broadened through dropping the requirement for amenorrhoea, extending the weight criterion to any significant underweight, and extending the cognitive criterion to include developmentally and culturally relevant presentations; c) a severity qualifier "with dangerously low body weight" should distinguish the severe cases of anorexia nervosa that carry the riskiest prognosis; d) bulimia nervosa should be extended to include subjective binge eating; e) binge eating disorder should be included as a specific category defined by subjective or objective binge eating in the absence of regular compensatory behaviour; f) combined eating disorder should classify subjects who sequentially or concurrently fulfil criteria for both anorexia and bulimia nervosa; g) avoidant/restrictive food intake disorder should classify restricted food intake in children or adults that is not accompanied by body weight and shape related psychopathology; h) a uniform minimum duration criterion of four weeks should apply.     

A “Coca-Cola” Shape: Cultural Change,Body Image,and Eating Disorders in San Andrés,Belize

Eating disorders have been associated with developing nations undergoing rapid social transition, including participation in a global market economy and heavy media exposure. San Andrés, Belize, a community with many risk factors associated with the cross-cultural development of eating disorders, has shown remarkable resistance to previously documented patterns, despite a local focus on female beauty. Drawing on longitudinal person-centered ethnography with adolescent girls, this article examines why this community appears exceptional in light of the literature. First, community beauty and body image ideals and practices are explicated. Then, a protective ethnopsychology is proposed as a key mediating factor of the rapid socio-cultural change among young women. Finally, possible nascent cases of eating disordered behavior are discussed in light of their unique phenomenology: that is, having to do more with economic opportunity in the tourism industry and less with personal distress or desire for thinness. Close, meaning-centered examination of eating and body image practices may aid understanding and prevention of eating disorders among adolescents undergoing rapid social change in situations of globalization and immigration.     

The case report of treatment strategy for Anorexia nervosa with psychotic elements in adolescent

Eating disorders in early childhood are the same frequency in boys and girls. During adolescence eating disorders are ten (10) times more frequent in girls than in boys. Worrying is the fact that eating disorders are the third chronic illness among adolescents after obesity and asthma. Depicting this adolescent we tried to show difficulty of treatment of this disorder, where in the beginning is important to stabilize body weight and prevent somatic damages such as: heart damage, amenorrhoea, changes in EKG (electrocardiogram) and electrolyte dysbalance that could endanger the life of patient. Simultaneously it is important to recognize and treat comorbid psychological disturbances such as in this case: depression, delusions with occasional psychotic reactions combined with unrealistic thinking about the layout of her own body. There is still no cure for the treatment of eating disorders which are in growing number of reports among male adolescents.     

Onset of adolescent eating disorders: population based cohort study over 3 years

ObjectiveTo study the predictors of new eating disorders in an adolescent cohort.DesignCohort study over 3 years with six waves.SubjectsStudents, initially aged 14-15 years, from 44 secondary schools in the state of Victoria, Australia.ResultsAt the start of the study, 3.3% (29/888) of female subjects and 0.3% (2/811) of male subjects had partial syndromes of eating disorders. The rate of development of new eating disorder per 1000 person years of observation was 21.8 in female subjects and 6.0 in male subjects. Female subjects who dieted at a severe level were 18 times more likely to develop an eating disorder than those who did not diet, and female subjects who dieted at a moderate level were five times more likely to develop an eating disorder than those who did not diet. Psychiatric morbidity predicted the onset of eating disorder independently of dieting status so that those subjects in the highest morbidity category had an almost sevenfold increased risk of developing an eating disorder. After adjustment for earlier dieting and psychiatric morbidity, body mass index, extent of exercise, and sex were not predictive of new eating disorders.ConclusionsDieting is the most important predictor of new eating disorders. Differences in the incidence of eating disorders between sexes were largely accounted for by the high rates of earlier dieting and psychiatric morbidity in the female subjects. In adolescents, controlling weight by exercise rather than diet restriction seems to carry less risk of development of eating disorders.

Key messages

• Adolescent females who diet at a severe level are 18 times more likely to develop an eating disorder than those who do not diet, and those who diet at a moderate level are five times more likely to develop an eating disorder
• High levels of psychiatric morbidity in females increase the risk of developing eating disorders by sevenfold
• Around two thirds of new cases of eating disorder arise in females who have dieted moderately
• The predominance of eating disorders in females is largely explained by the higher rates of earlier dieting and psychiatric morbidity
• Daily exercise seems to be a less risky strategy for controlling weight in adolescents

     

Selected auxological aspects of anorexia nervosa--relations of body weight to body height and menstrual cycle

Specific aspects of therapy of eating disorders in pubescent and adolescent girls are related to unfinished biological development in time of severe malnutrition. Namely the issues of 1) exact determination of recommended body weight (target weight, weight for discharge etc.) on the basis of the exact analysis of the weight history, 2) relation between body weight and menstrual cycle (menarche, amenorrhoea and remenorrhoea) and 3) risk of non-realization of the genetic growth potential (status of linear growth and skeletal maturity) are discussed in this article. The article brings the results of the data analysis of 90 inpatients with anorexia nervosa and the tables of the recommended target weight for adolescents with finished linear growth. The authors emphasize the importance of an exact analysis of growth and weight history and of reflection of biological age in girls with eating disorders for successful and reasonable realimentation therapy.     

Changes in Eating Attitudes,Body Esteem and Weight Control Behaviours during Adolescence in a South African Cohort

Failure to consume an adequate diet or over consumption during adolescence can disrupt normal growth and development, resulting in undesirable weight change. This leads to an increase in unhealthy weight control practices related to eating and exercise among both adolescent girls and boys to meet the societal ‘ideal’ body shape. This study therefore aims to examine the longitudinal changes in eating attitudes, body-esteem and weight control behaviours among adolescents between 13 and 17 years; and, to describe perceptions around body shape at age 17 years. A total of 1435 urban South African black and mixed ancestry boys and girls, who had data at both age 13 and 17 years from the Birth to Twenty cohort were included. Data were collected through self-administered questionnaires on eating attitudes (EAT-26), body esteem and weight control behaviours for either weight loss or muscle gain attempts. Height and weight were measured at both time points and BMI was calculated. Black females had a higher BMI (p<0.001) and an increased risk of developing eating disorders as well as significant increase in the prevalence of weight loss practices between the ages 13 and 17 years. At age 17 years both Mixed ancestry adolescents had lower body-esteem compared to black adolescents. The prevalence of possible eating disorders was 11% and 13.1% in early and late adolescents respectively. Males and females shared similar opinions on normal silhouettes being the ‘best’, ‘getting respect’ and being the ‘happiest’, while the obese silhouette was associated with the ‘worst’ and the ‘unhappiest’, and the underweight silhouette with the “weakest”. Black females had a higher BMI and an increased risk of developing eating disorders. Adolescent females engaged more in weight loss practices whereas, males in muscle gain practices indicating that Western norms of thinness as the ideal are becoming more common in South Africa.     

Integrated circuits and molecular components for stress and feeding: implications for eating disorders

Eating disorders are complex brain disorders that afflict millions of individuals worldwide. The etiology of these diseases is not fully understood, but a growing body of literature suggests that stress and anxiety may play a critical role in their development. As our understanding of the genetic and environmental factors that contribute to disease in clinical populations like anorexia nervosa, bulimia nervosa and binge eating disorder continue to grow, neuroscientists are using animal models to understand the neurobiology of stress and feeding. We hypothesize that eating disorder clinical phenotypes may result from stress‐induced maladaptive alterations in neural circuits that regulate feeding, and that these circuits can be neurochemically isolated using animal model of eating disorders.     

Latent class regression on latent factors

In the research of public health, psychology, and social sciences, many research questions investigate the relationship between a categorical outcome variable and continuous predictor variables. The focus of this paper is to develop a model to build this relationship when both the categorical outcome and the predictor variables are latent (i.e. not observable directly). This model extends the latent class regression model so that it can include regression on latent predictors. Maximum likelihood estimation is used and two numerical methods for performing it are described: the Monte Carlo expectation and maximization algorithm and Gaussian quadrature followed by quasi-Newton algorithm. A simulation study is carried out to examine the behavior of the model under different scenarios. A data example involving adolescent health is used for demonstration where the latent classes of eating disorders risk are predicted by the latent factor body satisfaction.     

An animal model of eating disorders associated with stressful experience in early life

Experience of childhood abuse is prevalent among patients with eating disorders, and dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis is implicated in its pathophysiology. Neonatal maternal separation is considered as an animal model of stressful experience early in life. Many of studies have demonstrated its impact both on the activity of HPA axis and the development of psycho-emotional disorders later in life. In this paper, a series of our researches on developing an animal model of eating disorders is reviewed. An animal model of neonatal maternal separation was used; Sprague-Dawley pups were separated from dam daily for 180 min during the first 2 weeks of life (MS) or undisturbed. Anxiety-/depression-like behaviors were observed in MS rats at the age of two months with decreased serotonergic activity in the hippocampus and the raphe. Post-weaning social isolation promoted food intake and weight gain of adolescent MS pups, with impacts on anxiety-like behaviors. Sustained hyperphagia was observed in the MS pups subjected to a fasting/refeeding cycle repeatedly during adolescence, with increased plasma corticosterone levels. Anhedonia, major symptom of depression, to palatable food was observed in adolescent MS pups with blunted response of the mesolimbic dopaminergic activity to stress. Results suggest that neonatal maternal separation lead to the development of eating disorders when it is challenged with social or metabolic stressors later in life, in which dysfunctions in the HPA axis and the brain monoaminergic systems may play important roles.     

Are Obese Adolescents and Young Adults at Higher Risk for Mental Disorders? A Community Survey

Objective: Associations between body mass index (BMI) and mental disorders meeting Axis-I diagnoses according to the Diagnostic and Statistical Manual for Mental Disorders IV (DSM-IV) were investigated in The Early Developmental Stages of Psychopathology Study in a large population-based sample, which included adolescents and young adults of both genders for the first time. Research Methods and Procedures: A total of 3021 German subjects ranging from 14 to 24 years of age were assessed for specific DSM-IV diagnoses derived from a modified version of the standardized Composite International Diagnostic Interview, and general psychological disturbances, using the Symptom Checklist-90-Revised. BMI percentiles for age and gender were calculated to avoid systematic bias in the BMI distribution resulting from the young age range represented in the sample. Additionally, subjects with a lifetime diagnosis of any eating disorder were excluded from statistical analysis to control the confounding effect of body weight-related eating disorders on associations between BMI and psychopathology. Results: The results based on logistic regression analyses and MANOVAs demonstrate that the BMI is not associated with mental disorders or general psychopathologies. There were no significant associations between BMI and mood, anxiety, substance, and somatoform disorders, a result that contrasts with almost all previous clinical studies. Additionally, in contrast to clinical investigations and most epidemiological studies, neither obesity nor underweight was significantly associated with any kind of general psychopathology. Discussion: The overall finding that obesity is not significantly related to marked psychopathology in the general German population of adolescents and young adults has important clinical implications.     

Gender Differences in Associations of Eating Pathology between Mothers and Their Adolescent Offspring

Objective: To study the association of eating pathology between mothers and their adolescent offspring in a population sample. Research Methods and Procedures: The participants were 481 women (mean age, 47 ± SD 5 years; BMI, 25 ± 4 kg/m²) and their 481 adolescent children 16 to 17 years old (BMI, 21 ± 3 kg/m²) of the Stockholm Weight Development Study. Assessment methods were the Three‐Factor Eating Questionnaire Revised 18 and the Eating Disorder Inventory 2. Results: A higher body weight was most related to cognitive restraint for adolescents and to emotional eating for adult women. A mother‐daughter link could be identified for eating pathology, with the strongest link found for emotional eating. No mother‐son link could be identified. Age subgroup analyses revealed a stronger mother‐daughter link for body attitudes in younger mothers and for cognitive restraint in older mothers. Discussion: Gender differences revealed that eating pathology was shared by mothers and daughters but not by mothers and sons. A psychological strategy such as eating as a response to negative emotions was most interrelated between mothers and daughters. Younger mothers shared more attitudes toward the body with their daughters, whereas older mothers shared more restrictive eating behaviors with their daughters. The mother‐daughter links found may be due to gender‐specific genetic and psychological family transmission and gender‐specific environmental influences. The sons’ eating behaviors seem to be more independent and would be formed by other factors than for the girls.     

Intrasexual competition and eating restriction in heterosexual and homosexual individuals

Restrictive eating attitudes and behaviors have been hypothesized to be related to processes of intrasexual competition. According to this perspective, within-sex competition for status serves the adaptive purpose of attracting mates. As such, status competition salience may lead to concerns of mating desirability. For heterosexual women and gay men, such concerns revolve around appearing youthful and, thus, thinner. Following this logic, we examined how exposure to high-status and competitive (but not thin or highly attractive) same-sex individuals would influence body image and eating attitudes in heterosexual and in gay/lesbian individuals. Results indicated that for heterosexuals, intrasexual competition cues led to greater body image dissatisfaction and more restrictive eating attitudes for women, but not for men. In contrast, for homosexual individuals, intrasexual competition cues led to worse body image and eating attitudes for gay men, but not for lesbian women. These findings support the idea that the ultimate explanation for eating disorders is related to intrasexual competition.     

Transdiagnostic risk of mental disorders in offspring of affected parents: a meta-analysis of family high-risk and registry studies

The offspring of parents with mental disorders are at increased risk for developing mental disorders themselves. The risk to offspring may extend transdiagnostically to disorders other than those present in the parents. The literature on this topic is vast but mixed. To inform targeted prevention and genetic counseling, we performed a comprehensive, PRISMA 2020-compliant meta-analysis. We systematically searched the literature published up to September 2022 to retrieve original family high-risk and registry studies reporting on the risk of mental disorders in offspring of parents with any type of mental disorder. We performed random-effects meta-analyses of the relative risk (risk ratio, RR) and absolute risk (lifetime, up to the age at assessment) of mental disorders, defined according to the ICD or DSM. Cumulative incidence by offspring age was determined using meta-analytic Kaplan-Meier curves. We measured heterogeneity with the I² statistic, and risk of bias with the Quality In Prognosis Studies (QUIPS) tool. Sensitivity analyses addressed the impact of study design (family high-risk vs. registry) and specific vs. transdiagnostic risks. Transdiagnosticity was appraised with the TRANSD criteria. We identified 211 independent studies that reported data on 3,172,115 offspring of parents with psychotic, bipolar, depressive, disruptive, attention-deficit/hyperactivity, anxiety, substance use, eating, obsessive-compulsive, and borderline personality disorders, and 20,428,575 control offspring. The RR and lifetime risk of developing any mental disorder were 3.0 and 55% in offspring of parents with anxiety disorders; 2.6 and 17% in offspring of those with psychosis; 2.1 and 55% in offspring of those with bipolar disorder; 1.9 and 51% in offspring of those with depressive disorders; and 1.5 and 38% in offspring of those with substance use disorders. The offspring's RR and lifetime risk of developing the same mental disorder diagnosed in their parent were 8.4 and 32% for attention-deficit/hyperactivity disorder; 5.8 and 8% for psychosis; 5.1 and 5% for bipolar disorder; 2.8 and 9% for substance use disorders; 2.3 and 14% for depressive disorders; 2.3 and 1% for eating disorders; and 2.2 and 31% for anxiety disorders. There were 37 significant transdiagnostic associations between parental mental disorders and the RR of developing a different mental disorder in the offspring. In offspring of parents with psychosis, bipolar and depressive disorder, the risk of the same disorder onset emerged at 16, 5 and 6 years, and cumulated to 3%, 19% and 24% by age 18; and to 8%, 36% and 46% by age 28. Heterogeneity ranged from 0 to 0.98, and 96% of studies were at high risk of bias. Sensitivity analyses restricted to prospective family high-risk studies confirmed the pattern of findings with similar RR, but with greater absolute risks compared to analyses of all study types. This study demonstrates at a global, meta-analytic level that offspring of affected parents have strongly elevated RR and lifetime risk of developing any mental disorder as well as the same mental disorder diagnosed in the parent. The transdiagnostic risks suggest that offspring of parents with a range of mental disorders should be considered as candidates for targeted primary prevention.     

Tooth Erosion and Eating Disorders: A Systematic Review and Meta-Analysis

Background

Eating disorders are associated with the highest rates of morbidity and mortality of any mental disorders among adolescents. The failure to recognize their early signs can compromise a patient''s recovery and long-term prognosis. Tooth erosion has been reported as an oral manifestation that might help in the early detection of eating disorders.

Objectives

The aim of this systematic review and meta-analysis was to search for scientific evidence regarding the following clinical question: Do eating disorders increase the risk of tooth erosion?

Methods

An electronic search addressing eating disorders and tooth erosion was conducted in eight databases. Two independent reviewers selected studies, abstracted information and assessed its quality. Data were abstracted for meta-analysis comparing tooth erosion in control patients (without eating disorders) vs. patients with eating disorders; and patients with eating disorder risk behavior vs. patients without such risk behavior. Combined odds ratios (ORs) and a 95% confidence interval (CI) were obtained.

Results

Twenty-three papers were included in the qualitative synthesis and assessed by a modified version of the Newcastle-Ottawa Scale. Fourteen papers were included in the meta-analysis. Patients with eating disorders had more risk of tooth erosion (OR = 12.4, 95%CI = 4.1–37.5). Patients with eating disorders who self-induced vomiting had more risk of tooth erosion than those patients who did not self-induce vomiting (OR = 19.6, 95%CI = 5.6–68.8). Patients with risk behavior of eating disorder had more risk of tooth erosion than patients without such risk behavior (Summary OR = 11.6, 95%CI = 3.2–41.7).

Conclusion

The scientific evidence suggests a causal relationship between tooth erosion and eating disorders and purging practices. Nevertheless, there is a lack of scientific evidence to fulfill the basic criteria of causation between the risk behavior for eating disorders and tooth erosion.     

Selective Visual Attention during Mirror Exposure in Anorexia and Bulimia Nervosa

Objective

Cognitive theories suggest that body dissatisfaction results from the activation of maladaptive appearance schemata, which guide mental processes such as selective attention to shape and weight-related information. In line with this, the present study hypothesized that patients with anorexia nervosa (AN) and bulimia nervosa (BN) are characterized by increased visual attention for the most dissatisfying/ugly body part compared to their most satisfying/beautiful body part, while a more balanced viewing pattern was expected for controls without eating disorders (CG).

Method

Eye movements were recorded in a group of patients with AN (n = 16), BN (n = 16) and a CG (n = 16) in an ecologically valid setting, i.e., during a 3-min mirror exposure.

Results

Evidence was found that patients with AN and BN display longer and more frequent gazes towards the most dissatisfying relative to the most satisfying and towards their most ugly compared to their most beautiful body parts, whereas the CG showed a more balanced gaze pattern.

Discussion

The results converge with theoretical models that emphasize the role of information processing in the maintenance of body dissatisfaction. Given the etiological importance of body dissatisfaction in the development of eating disorders, future studies should focus on the modification of the reported patterns.     

Low self-esteem and psychiatric patients: Part I - The relationship between low self-esteem and psychiatric diagnosis

BACKGROUND: The objective of the current study was to determine the prevalence and the degree of lowered self-esteem across the spectrum of psychiatric disorders. METHOD: The present study was carried out on a consecutive sample of 1,190 individuals attending an open-access psychiatric outpatient clinic. There were 957 psychiatric patients, 182 cases with conditions not attributable to a mental disorder, and 51 control subjects. Patients were diagnosed according to DSM III-R diagnostic criteria following detailed assessments. At screening, individuals completed two questionnaires to measure self-esteem, the Rosenberg self-esteem scale and the Janis and Field Social Adequacy scale. Statistical analyses were performed on the scores of the two self-esteem scales. RESULTS: The results of the present study demonstrate that all psychiatric patients suffer some degree of lowered self-esteem. Furthermore, the degree to which self-esteem was lowered differed among various diagnostic groups. Self-esteem was lowest in patients with major depressive disorder, eating disorders, and substance abuse. Also, there is evidence of cumulative effects of psychiatric disorders on self-esteem. Patients who had comorbid diagnoses, particularly when one of the diagnoses was depressive disorders, tended to show lower self-esteem. CONCLUSIONS: Based on both the previous literature, and the results from the current study, we propose that there is a vicious cycle between low self-esteem and onset of psychiatric disorders. Thus, low self-esteem increases the susceptibility for development of psychiatric disorders, and the presence of a psychiatric disorder, in turn, lowers self-esteem. Our findings suggest that this effect is more pronounced with certain psychiatric disorders, such as major depression and eating disorders.     

Propositions pour une perspective ph��nom��nologique dans l��autisme infantile

During the twentieth century, many clinical psychiatrists established links with ??continental phenomenology.?? In France, the most famous were Minkowski, Tatossian and Lantéri-Laura. They worked on schizophrenia and bipolarity disorders in adulthood. So, they were not interested in child development disorders. In the same time, Kanner described autism in a phenomenological way. But, this had been sometimes forgotten or neglected. Keeping in mind the work of these famous psychiatrists, we first discuss the interest of phenomenology in child and adolescent psychiatry, especially in case of autism. Second, in spite of Rutter??s critics, using phenomenology, we try to explain why Kanner chose the word ??autism?? to name the syndrome he had described. Third, taking a phenomenological point of view, we show the impact of sameness and sensory disorders on children with autism and their families. In conclusion, we insist on the interest of phenomenology in childhood autism to link research in developmental and cognitive psychology and the day-to-day life of the child or the adolescent.     

"Whatever feels good in my soul": body ethics and aesthetics among African American and Latina women

Ethnicity-specific differences in body aesthetic ideals and body satisfaction have been cited as a potential explanation for interethnic differences in the prevalence and presentation of eating disorders. It has been widely hypothesized that such ethnically based differences in aesthetic body ideals mitigate cultural pressures that contribute to body disparagement and disordered eating among white women. However, mechanisms by which a cultural milieu may be protective against the development of disordered eating remain poorly understood. This study investigated relationships among ethnicity, self-representation, and body aesthetic ideals among 18 college-educated black and Latina women through analysis of focus group discussion data. Rather than confirming body aesthetic ideals different from those of white culture, study respondents reframed the discussion about body aesthetics to one of body ethics. That is, study subjects both contested ideologies defining thinness and whiteness as inherently beautiful and espoused a body ethic of self-acceptance and nurturance that rejects mainstream cultural pressures to reshape bodies to approximate aesthetic ideals promulgated in the media. We conclude that understanding body image concerns from the standpoint of body ethics, rather than body aesthetics, may be a more productive and inclusive approach to the study of ethnically diverse women's embodied experience. Ultimately it is anticipated that this will better illuminate the complex relationships among ethnicity, culture, and risk for body image and eating disorders.     

Intracellular and computational evidence for a dominant role of internal network activity in cortical computations

The mammalian cerebral cortex is characterized by intense spontaneous activity, depending on brain region, age, and behavioral state. Classically, the cortex is considered as being driven by the senses, a paradigm which corresponds well to experiments in quiescent or deeply anesthetized states. In awake animals, however, the spontaneous activity cannot be considered as 'background noise', but is of comparable-or even higher-amplitude than evoked sensory responses. Recent evidence suggests that this internal activity is not only dominant, but also it shares many properties with the responses to natural sensory inputs, suggesting that the spontaneous activity is not independent of the sensory input. Such evidence is reviewed here, with an emphasis on intracellular and computational aspects. Statistical measures, such as the spike-triggered average of synaptic conductances, show that the impact of internal network state on spiking activity is major in awake animals. Thus, cortical activity cannot be considered as being driven by the senses, but sensory inputs rather seem to modulate and modify the internal dynamics of cerebral cortex. This view offers an attractive interpretation not only of dreaming activity (absence of sensory input), but also of several mental disorders.