An eating disorder is more than just disordered eating : bio-psycho-social perspectives

Sammanfattning: Several reports show that stress and psychiatric ill health are increasing in adolescents. Eating disorders (ED) and related conditions such as depression, self-injurious behaviour and suicide attempts are becoming more common, especially among young women. Eating disorders include two main categories: anorexia nervosa (self-starvation) and bulimia nervosa (binge eating and compensatory actions). These disorders do not only involve deviations in eating behaviour, but also include several severe physiological and psychiatric symptoms. The aetiology of eating disorders remains largely unclear, and multifactorial models that integrate biological, psychological and social perspectives are necessary in the investigation of risk factors and the natural history of these conditions. The overall aim of the present thesis was to integrate bio-psycho-social aspects in the study of the aetiology and clinical course of eating disorders. The studies included are based on two different data sets. Study I is based on the Uppsala Birth Cohort Multigenerational Study (UBCoS Multigen), a longitudinal register-based study including information about families spanning over three generations. The sample includes all men and women born at the Uppsala University Hospital between the years 1915-1929 and their descendants born up to 2002. The database is unique in enabling researchers to study intergenerational associations. The second data set is a clinical sample of severely ill, eating disorder inpatients from a specialized clinic (Study II-IV). Our results indicate that social background can be of importance in the development of eating disorders; higher education in parents and maternal grandparents was associated with higher risk of hospitalization for ED. Further we found a higher risk of ED in women with the highest marks in school. The clinical studies showed that patients with eating disorders had higher scores on somatic stress and physiological tension, as well as on cognitive-social anxiety as compared to healthy controls. The co-morbidity with self-injurious behaviour and suicide attempts was high, especially in patients with bulimia nervosa. Among the bulimia nervosa patients low social adaptation, negative childhood environment and low childhood adjustment were more common. Biological markers as measured by cytokines showed higher levels of pro-inflammatory proteins in the patient group. Personality traits indicating anxiety and aggression were associated with increased levels of cytokines. Finally neuropsychological impairments and negative self-evaluations were common in both anorexia and bulimia nervosa. Eating disorders are to be considered an increasing public health problem. Studies on the interplay between social factors, interpersonal variations in behaviour, and biological aspects of eating pathology are essential for a better understanding of eating disorders.