Clinical Flashcards
Anorexia nervosa
An eating disorder characterised by persistent low body weight. There are three main criteria that must be met for a diagnosis to be given.
Anorexia nervosa - criterion A
Restriction of energy intake resulting in body weight being significantly below what would be expected based on the patients age and height (BMI under 17.5)
Anorexia nervosa - criterion B
An intense fear of gaining weight or participating in persistent behaviour that will interrupt the gaining of weight even though current body weight is very low. E.g. excessive exercise or purge-binge
Anorexia nervosa - criterion C
Distortion of body image where the body weight is hugely overestimated and the patient is unable to accept the severity of the low body weight. There is an emphasis on body weight in the patients view of themselves leading to poor body image.
Anorexia nervosa - features (onset)
Usually diagnosed in teenage years (13-18), often coinciding with stressors such as starting university or leaving home
Anorexia nervosa - features (prevalence)
1:10 Male to female ratio, 3.6% prevalence in females, 0.1% in males, high prevalence in high income countries
Anorexia nervosa - features (prognosis)
High mortality rate, six times as many deaths as expected for females, staying longer during the first hospitalisation predicted better outcomes
Anorexia nervosa - physical symptoms
Affects the whole body. Symptom include: thinning hair, low blood pressure, weak muscles, osteoporosis, kidney stones, intestinal problems, periods stopping and bruising easily.
Anorexia nervosa - subtypes - restrictive
Weight loss shown through dieting, excessive exercise or fasting in significant periods within the last three months
Anorexia nervosa - subtypes - binge eating/purging
Recurrent bouts of binge eating behaviours alternating with purging, such as self induced vomiting or laxatives, shown within the last three months
Anorexia nervosa - reliability of diagnosis
Strength - Sysko et al (2012)
Weakness - Thomas et al (2015)
Sysko et al (2012)
Measured test-retest reliability with patients being interviewed by telephone using the DSM-5 criteria, three to seven days later the interview was repeated using a different assessor. The extent of agreement was described as excellent
Thomas et al (2015)
Pointed out that many studies go beyond the DSM-5 criteria, for instance using the BMI cut off of 17.5, therefore reliability may be lower in real life.
Anorexia nervosa - validity of diagnosis
Weakness - Smith et al (2017)
Smith et al (2017)
Looked at the validity of four severity specifiers. In 109 adults diagnosed with anorexia nervosa, a higher BMI (indicating low severity) was linked to greater eating disorder psychopathology, the opposite of the expected outcome.
Co- morbidity
Anorexia nervosa is associated with comorbidity, where two or more medical conditions are simultaneously present in the patient
Classification system definition
A checklist of signs and symptoms which helps a clinician to reach a diagnosis of a specific disorder, often through a process of elimination
DSM-5 (Diagnostic and statistical manual)
Describes the symptoms, features and risk factors of over 300 mental and behavioural disorders
DSM-5 - section one
Offers guidance about using the new system
DSM-5 - section two
Details the disorders and is categorised according to our current understanding of the underlying causes and similarities between the symptoms, it is used to provide a diagnosis.
DSM-5 - section three
Includes suggestions for new disorders, which currently require further investigation. It also includes information on the effect of culture on the presentation of symptoms and how they are presented
Diagnosing using the DSM-5
Clinicians would gather information about an individual through observation and interviews (structured and unstructured).
Process of elimination, with a best-fit system
DSM-5 - inter-rater reliability
Two clinicians interview the same individual, strong reliability if they both reach the same diagnosis
DSM-5 - test-retest reliability
The diagnosis is repeated by the same clinician after a time period, strong reliability if the same diagnosis is reached