Due to the complex nature of eating disorders, there are often co-morbid behaviours and psychological disturbances and this can affect the effectiveness of cognitive behavioural therapy. Fitcher et al (1994) concluded that extreme perfectionism, very poor self-esteem and dissociative responses to trauma respond better to schema focused therapy as opposed to cognitive behavioural therapy. It is also important to consider how malnutrition can affect cognitive processes and Isis et al (2007) found that the brain cannot process therapy effectively when body mass index is below 15. On the contrary, Accurso et al (2014) found that if the patient has a strong desire to change and accept therapy, low weight does not correlate with how effective treatment
