[Selected issues of biological aspects of eating disorders]

This paper reviews the recent progress in the understanding of the neurobiology of the eating disorders. The analysis of the biochemical abnormalities present in the patients with bulimia nervosa indicates the decrease of central serotonin and noradrenalin activity, elevation of the levels of cerebrospinal fluid peptide YY, alterations of the endogenous opioids and also reduction of peripheral cholecystokinin levels. As these studies were performed on patients who were actively binging and purging it is conceivable that the above abnormalities can results from a pathological feeding pattern. It is also suggested that the reduction of central serotoninergic activity is the stable, trait-related dysregulation of neurotransmitter system activity. In patients with anorexia nervosa the endocrine disturbances of the hypothalamic-pituitary-ovarian and hypothalamic-pituitary-adrenal axes were thoroughly studied. Underweight anorectic patients have been found to have elevations of cerebrospinal fluid level of neuropeptide Y, corticotropin releasing hormone and vasopressin as well as reductions of beta-endorphin and oxytocin level. However, most of the neuropeptide alterations normalize following weight recovery. The only exception is a persistent increase of central serotonin activity postulated to be responsible for the obsessive-compulsive personality traits and disturbed eating behaviors found in these patients.