Purge
After bingeing the individual with bulimia is likely to purge her/himself to compensate for the overindulgence and in order to prevent weight gain. This is achieved by self-induced vomiting or misuse of laxatives or other medications. Alternatively the individual with bulimia may stop eating for a long period as means of purging.
Frequency:
In order to be diagnosed as suffering from bulimia an individual should have been displaying binge eating an inappropriate compensatory behaviours, on average, atleast twice a week for 3 months.
Body Image
As with people with Anorexia, the self image and self esteem of the individual with bulimia are unduly influenced by body shape and weight, someone suffering from Bulimia has an inappropriate perception of his/her body.
Different from Anorexia:
Because purging or other compensatory behaviour follows the binge-eating episodes, people with bulimia are usually within the normal range of weight for their age and height. However, like individuals with Anorexia, they may fear gaining weight, have a strong desire to lose weight, and feel intensely dissatisfied with their bodies. People with Bulimia often perform the behaviours in secret, feeling disgusted and ashamed when they binge, yet relieved once they purge.
Differences between Anorexia Nervosa and Bulimia Nervosa
Biological Explanations of Anorexia Nervosa
Twin and Family studies, such as the study by Holland ET AL., (1988) indicate that Anorexia is caused by inherited (genetic factors).
Gorwood ET AL. (1998) suggest that genes may dictate abnormal levels of neurotransmitters or abnormal development of the hypothalamus.
Klump ET AL. (2000) suggests that people with anorexia and their parents have an obsessive compulsive disorder that produces perfectionist behaviour. This can be seen in an obsessive interest in food.
Biochemical factors
Serotonin –
There is considerable evidence that increased Serotonin activity in the brain is associated with a suppressed appetite and also with increased anxiety, obsessive behaviour, phobias and even vomiting- all characteristics of people with anorexia.
Adrenaline and cortisol –
When the body responds to stress Adrenaline and cortisol are produced and one effect is to reduce appetite. When stress dies down, appetite should return to normal but it is possible that this does not happen to people with anorexia because they lack the hormone to switch the appetite back on (called AVP). A key characteristic of anorexia is that people with the disorder can resist the need to eat, and this explanation accounts for this.
Biochemical factors as a cause or effect of anorexia nervosa –
The starvation hypothesis suggests that neurotransmitter and hormone disorders are a consequence rather than a cause of emotional distress. Fichter and Pirke (1995) starved normal individuals, which caused changes in neurotransmitter and hormone levels, supporting the view that starvation causes the changes rather than vice versa. it may be that, once starvation is under way, this leads to changes that then become symptoms of the disorder.
The Psychodynamic approach
Freud suggested that eating was a substitute for sexual activity. Therefore, not eating was a way to repress sexual thoughts and the onset of sexual maturity. Starvation in adolescence is also a means of avoiding the development of an adult’s body. Restricted food intake prevents menstruation and development of secondary sexual characteristics, such as breasts and enlarged hips. By preventing adult development and adolescent can avoid anxieties associated with adulthood and mature sexuality.
Bruch (1980) has proposed a more recent psychodynamic explanation of the development of anorexia in terms of poor parenting and a struggle for autonomy. The origins of anorexia are in early childhood, when the mother does not cope adequately with her child’s needs. e.g. she may offer the child food when the child was expressing anxiety. This leads the child to feel ineffectual because his or her signals are not appropriately responded to. Such children fail to develop self-reliance and are especially sensitive to criticism from others.
In adolescence, the conflict between maternal dependence and the child’s wish for independence results in anorexia as a means of exerting self-control. At the same time, the mother’s continuing relationship problems mean a desire on the mother’s part to retain dependence and encourage immaturity in her child, both in body and mind.
The behavioural approach
The Principles of the classical and operant conditioning –
The first step is learning the difference between thinness and admiration. The individual learns to associate slimness (previously a neutral stimulus) with admiration and feeling good about him/herself (a stimulus)
The second step is operant conditioning. Continuing admiration is reinforcing. In addition, refusing to eat and excessive weight loss may attract increased attention, which is rewarding. The individual may gain personal satisfaction because weight loss acts as a punishment to parents.
The influence of the media-
It is the media (e.g. magazines, films, toys…) that creates the social norm that ‘thin is good’. We say that thin models and film stars receive admiration and attention (vicarious reinforcement), and therefore we imitate the behaviour. This media explanation centers around indirect (vicarious) learning through operant conditioning (social learning theory).
Anorexia as Culture bound syndrome (CBS) –
The media explanation is also a cultural explanation. The media transmits social norms and cultural values. It is our culture that values thinness. This means that one way to test this hypothesis is to look at the incidence of anorexia in other cultures. The incidence of anorexia in other cultures is rare. e.g. Sui Wah (1989) reported that anorexia is rare in black populations in Western and non-Western cultures, and in China. The Chinese have a cultural norm of respect for food, which means that thinness is not valued.
DiNicola (1990) argues that culture acts as a cause by providing a blue print for anorexia. It is a culture-bound syndrome of Westernised cultures. However, the concept of anorexia as a CBS is not without objectors. Hoek et al. (1998) set out to test the view that anorexia is rare in other cultures. The researchers examined the records of 44,192 people admitted to hospital between 1987 and 1989 in Curacao, a non-Westernised Caribbean Island where it is acceptable to be overweight. They found 6 cases, a rate that they claim is within the range of rates reported in Western countries.
The Cognitive approach
An individual with anorexia, according to the cognitive model, is an individual who is preoccupied with the way he or she looks – or thinks he or she looks. People with anorexia often perceive themselves as unattractive and/or overweight. The cognitive model can explain why only some dieters develop anorexia. We are all exposed to the thinness model but only those with faulty belief systems are affected because they don’t ‘see’ their excessive weight loss.
Bemis-Vitousek and Orimoto (1993) pointed out the kind of faulty cognitions that are typical in people with anorexia. e.g. a common cognition is that dieting is a means of exerting self-control, but at the same time most people with anorexia are aware that they are out of control because they can’t stop dieting, even though they know it is threatening their life. These are faulty cognitions and maladaptive ways of thinking.
Biological explanations of Bulimia Nervosa
Genetic Factors
The studies by Kendler et al. and Bulik et al. both provided evidence that bulimia is inherited. Genetic factors may lead to biochemical or neuroanatomical abnormalities, or they may lead to dispositional differences.
Biochemical Factors
Serotonin – It has been suggested that serotonin may be involved in bulimia but in a way that is different to its involvement in anorexia. Increased serotonin activity in the brain may be responsible for anorexia.
Whereas decreased serotonin activity may be responsible for bulimia. (Galla, 1995). This makes sense because people with bulimia overeat and then feel guilty because of the desire to be thin.
An increased consumption of Carbohydrates increases the production of serotonin. This has lead to the use of selective serotonin reuptake inhibitors (SSRIs) in the treatment of bulimia.
Serotonin either predisposes an individual to develop bulimia, or perpetuates the disorder, or both.
Individuals with bulimia may diet because they cannot trust their own physical self-regulators, which sets a vicious cycle in motion leading to related emotional changes that perpetuate and result in abnormal eating behaviours.
Neuroanatomy
As with anorexia, the hypothalamus plays a role in bulimia. Damage to the hypothalamus can result in overeating or undereating. In animals damage to the ventromedial hypothalamus (VMH) results in overeating. This happens because the lateral hypothalamus (LH) stimulates eating and the VMH is damages, there is no sense of satiety and overeating occurs, which may result in obesity. In an individual who wishes to be thin, overeating is controlled as far as possible but may then result in excessive binge, which further results in compensation through purging.
Serotonin is linked to this process because it helps to regulate the feeding centers of the hypothalamus. Low levels of serotonin stimulate the LH.
