A Review of Anorexia Nervosa, Its Relationship to Autism and Borderline Personality Disorder, and Implications for Patient Related Outcomes

Author(s): Clive Kelly, Matthew Davies

Anorexia Nervosa (AN) is a serious psychiatric disorder associated with reduced intake of food, increased energy expenditure and psychological features, in which a low body weight is deliberately maintained and the patient experiences an associated body-image distortion. AN has recently been shown to share expression with additional mental health disorders including both Autistic Spectrum Disorder (ASD) and Borderline Personality Disorder (BPD). These associations may have implications for outcomes and therapeutic intervention. Phenotypes of ASD and BPD merge in the psyche of some women with AN. In essence, women with early onset AN in whom the diagnosis of ASD is made a decade or more later, are most likely to demonstrate a mix of personality features. The abnormal Neuropsychology underpinning the links between these three conditions is complex. The limbic system which controls emotions, via the hippocampus, amygdala and prefrontal cortex, is known to be both structurally and functionally different in patients with AN, ASD and BPD, as evidenced by neuroimaging studies. AN is associated with multiple effects on the endocrine system. Growth hormone, sex hormones and cortisol levels all rise, producing a unpredictable mix of outcomes. Bone density is reduced in 90% of cases, with an additional acceleration in bone loss. Fractures of the spine and pelvis occur in women as young as thirty. Women who develop early onset AN often demonstrate above average competitive drive and intelligence but may be stunted in terms of skeletal growth, social integration and emotional maturity. As the limbic system is linked to the endocrine system via the HPA axis, the exaggerated physiological responses associated with endocrine hyperactivity described above may directly or indirectly relate to the transference of heightened emotional states into harm of self or others. This combination of clinical features produces a range of challenges for those who su