Serotonin – Depression and bulimia occur together, so psychologists believe there is a common link between the two. For example both have been linked with imbalances in the levels of serotonin. Kaye et al found the levels of serotonin were abnormal in recovering bulimics compared to people who had never experienced bulimia.
Low levels of serotonin result in depression whilst high levels result in anxiety. So it could be that bulimics binge-eat to relieve the depression but then suffer from anxiety so purge to reduce this, which could make them depressed again, so the cycle continues.
Nitric oxide – Nitric oxide is involved in regulating how much food we take in. It regulates how much we produce of certain hormones and chemicals, thus controlling our eating behaviour.
Vannacci et al found that high levels of Nitric oxide correlated with bulimia and the frequency of binge-eating.
Evaluation of neural explanations
If neural explanations are true then we should be able to solve the problem using chemicals and medicine, so this is a strength of this explanation as it gives us a way to deal with the problem as well.
Research by Walsh supports this view too. 22 patients were given either ‘fluoxetine’, a drug used to raise serotonin levels or a placebo. They found significant improvements in the patients given fluoxetine, suggesting a link between serotonin levels and bulimia nervosa.