An eating disorder of psychological origin or the result of neurological disease – for example, a lesion of the HYPOTHALAMUS. Bulimia nervosa is linked to anorexia nervosa and is sometimes called the binge and purge syndrome. It is characterised by overpowering urges to eat large amounts of food, followed by induced vomiting or abuse of laxatives to avoid gaining weight. The condition is most common in women in their 20s; it is accompanied by irregular menstruation, often amounting to amenorrhoea (see MENSTRUATION). Although there are many similarities to anorexia nervosa, bulimia nervosa differs in that there is no attempt at deceit; sufferers freely admit to an eating disorder and feel distress about the symptoms that it produces. In spite of this, the response to treatment is, as in anorexia nervosa, far from satisfactory. (See EATING DISORDERS.)