Eating Disorders

Introduction

Anorexia nervosa (AN), bulimia nervosa (BN) and binge eating disorder (BED) are complex disorders in which a great variety of factors are implicated. Due to this complexity, a great diversity of instruments is required to collect the data needed to complete the initial assessment, to design the treatment plan, and to evaluate the outcomes. The aim of the initial assessment must be to gather information not only about weight and eating behaviour, but also about all the factors that are related to the onset, course and maintenance of the disorder. It is necessary to have in mind that a variety of professionals may collaborate in the care of these patients. Different levels of assessment are needed to complete the evaluation of eating disorders (see Table 1). First of all, a full physical examination should be preformed and laboratory analysis should be determined before the psychological assessment begins. For making treatment decisions, it is very important to know the patient's nutritional state, vital signs, physical and sexual growth and development, the cardiovascular system, evidence of dehydration, lanugo, salivary gland enlargement, etc. This knowledge is especially important in AN patients with great weight loss or in BN patients with a high frequency of vomiting. Then, attention must be paid to weight and the history of the eating disorder, the eating behaviour, binge eating and compensatory behaviours such as vomiting, misuse of laxatives or diuretics, fasting and/or excessive exercise. More specific factors like body image, cognitive concerns, emotional state and comorbility with other disorders, especially affective and anxiety disorders, obsessive-compulsive disorder, personality disturbance and substance abuse, should be analysed too. It is very important to remember that these eating disorder patients frequently deny their problem. In consequence, it will be necessary to gather information from other family members and from different instruments on the same topics to validate the data. To reach all these goals, a great variety of instruments are required. A full review of these instruments can be found in Allison (1995), Rosen and Srebnik (1990) and Saldaña (1994).

Body Weight Assessment

Information on a patient's weight is very important especially in AN patients in which diagnostic criteria are related with underweight. There are several indexes, which allow us to know if a person is normal weight, underweight or overweight. Commonly accepted indexes are the index of relative weight (RWI) and the Quetelet index or Body Mass Index (BMI). Both of them are used for diagnostic criteria, the former in the DSM-IV (APA, 1994) and the last in the ICD-10 (WHO, 1992). However, the most recommended index is the BMI which can be calculated by the following formula [BMI = Weight (in kg)/height (in m)2]. A BMI [Page 346][Page 347]between 20 and 25 represents normal weight, a value above 25 overweight, between 18 and 20 mild underweight and below 17 severe underweight. In the ICD-10, a BMI below 17.5 is the diagnostic criteria for AN. BMI is a good index that not only informs about patients' weight but also on their nutritional status.

Assessment of Eating Habits and Compensatory Behaviours

The assessment of these important factors should be done through different instruments. Interviews, self-report questionnaires and self-monitoring records that are completed by patients.

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