One of the reasons it is difficult to know if a disruption in the serotonin system causes eating disorders is

People with eating disorders often have depression as well.

Explanation:

An eating disorder is called a mental disorder. It is categorized and defined by uncommon eating habits that can affect a person's health. (negatively affect mental and physical health).

Eating disorders result from the interchange of different types of biological and environmental factors. The brain is known as central to understanding why some people develop eating disorders, and how they can recover through it.