Psychobiological Influence of Estrogen on the Serotonin System in Anorexia Nervosa: A Grant Proposal for Treatment Effects

Anorexia Nervosa has a stereotypic presentation of onset that involves a large gender disparity, with more cases occurring in women (American Psychiatric Association, 1994). This eating disorder also has a common age of onset, beginning around adolescence (Hoek & van Hoeken, 2003). The greater likelihood of female patients with a pubertal age of onset, suggests the influence of estrogen on the development and recovery from the disorder. Estrogen’s involvement in the disorder is related to the hyperactive HPA-axis and serotonin system that is present in those who develop anorexia nervosa. This hyperactivity creates a susceptibility to heightened levels of anxiety in these patients (Kaye, 2008). Estrogen production during puberty is thought to exacerbate anxiety even further, accounting for the common age of onset in the disorder (Klump et al., 2003). Nevertheless, throughout the illness, a reduction in estrogen by way of starvation and low body weight is thought to decrease serotonin activity (Hildebrandt et al., 2010). The non-effectiveness of SSRIs may be related to this decrease in serotonin activity in low weight patients (Ferguson et al., 1999). It has been suggested that depleted estrogen is related to depleted serotonin production during the illness, which hinders the effectiveness of SSRIs. The proposed study would observe estrogen levels in anorexic adolescent girls. Throughout their treatment, disordered eating symptoms would also be measured. It is expected that symptoms would be alleviated throughout treatment. Also, it is expected that only during later stages of treatment would patients receiving SSRI treatment experience greater symptom reduction than those not receiving SSRI treatment. These findings could suggest improvements to treatment protocol, whereby estrogen monitoring throughout recovery can provide therapists with an indicator of when SSRIs should be introduced into treatment