It is thought that initially, eating disorder behaviours such as restricting or binging may help reduce feelings of anxiety people may have (7)(8). However, this relief does not last long and a cycle of eating disorder behaviour often begins. Studies around this have been quite small and have explored this behaviour and patterns in very controlled experimental circumstances so may not be accurate for all people.
Some brain studies have shown that grey matter (part of the brain involved in muscle control and processing information from our senses) is at a reduced volume, likely shrunk due to starvation, in people with anorexia. However, one group of researchers (9)found that individuals with anorexia had more grey matter than those without an eating disorder. The grey matter was greater in the front of the brain in an area called the orbitofrontal cortex. This part of the brain is responsible for cognitive processing of things like taste and touch and is used in decision-making. They also found a difference between individuals with anorexia and those without in regards to white matter, which joins the grey matter together and transmits signals between brain areas. The white matter was found to be higher in the front underside of the brain (anteroventral) but lower in the back frontal lobe (posterior frontal) and parietal regions (to do with sensation, perception and sensory input with visual system). The same study found an association which showed that the greater the volume of grey matter in an individual with anorexia’s brain, the less pleasant they found the taste of a sugar syrup. It is thought that the association could be a factor in food avoidance in individuals with anorexia.
Research has also found that people with eating disorders may experience “rewards” differently to those without.(10) Structural neuro imaging (brain scans) have also shown that in both people with anorexia and bulimia, the brain structure is altered which may result in changes that have been associated with taste and reward value. This means that those with eating disorders may not feel the same way as those without in response to “rewards” i.e. eating, exercise.
It is though that grey and white matter can increase following weight restoration (10)(11)which will hopefully improve brain functioning and support cognitive abilities as well as other functions.
It’s important to note that during childhood to adulthood, the brain is developing. It is thought that the brain continues to develop right up until 25 years of age. Some of the changes are dependent on the onset of puberty, which we know starvation can have a significant impact on. Puberty is a time when some thinking processes and connections (the grey matter areas) in a person’s brain are lost or strengthened, depending on if they are used. The process starts at the back of the brain (posterior) and moves to the front (prefrontal cortex – decision making, problem solving and impulse control). During this time the brain uses a specific part (the amygdala) to make decisions which is responsible for dealing with emotions, impulse and instinct behaviour.
A starved state enhances obsessive and specific eating disorder traits, so it’s important to prevent this in order to support the typical development of the adolescent brain.
As you can see, the research around the brain is very complex and still unclear.
However, we do know that eating disorders do impact on the brain’s functioning. This is important as young people’s brains are still developing.
For adolescents, the last part of the brain to fully develop is the frontal lobe, the area to manage and evaluate the consequence of actions. As a parent, it can be really helpful for you to have the young person’s dreams and hopes for the future – the ones they had before they were unwell – in mind, as your loved one may forget these due to the eating disorder. If these are forgotten, the young person may feel that they only have the eating disorder or it’s the only thing they are good at.
Read more here: Adolescent Brain Development by Sarah-Jayne Blakemore & Mo Costandi (2014)