Neuroscience has led to a deeper understanding of the chemical imbalances present in a disordered brain. In turn, this has resulted in the creation of new treatments and medications to treat these disorders. When these new treatments are first being tested, the experiments prompt ethical questions. First, because the treatment is affecting the brain, the side effects can be unique and sometimes severe. Many subjects have claimed to have experienced “personal identity” changes during neurological treatment tests. This is a difficult ethical dilemma. There are no clear and undisputed definitions of personality, self, and identity. Neurological treatments can result in patients losing parts of “themselves” such as memories or moods. Yet another ethical dispute in neurological treatment research is the choice of patients. From a perspective of justice, priority should be given to those who are most seriously impaired and who will benefit most from the intervention. However, in a test group, scientists must select patients to secure a favorable risk-benefit ratio. Setting priority becomes more difficult when a patient’s chance to benefit and the seriousness of their impairment do not go together. For example, many times an older patient will be excluded despite the seriousness of their disorder simply because they are not as strong or as likely to benefit from the treatment. The main ethical issue at the heart of neurological treatment research on human subjects is promoting high-quality scientific research in the interest of future patients, while at the same time respecting and guarding the rights and interests of the research subjects. This is particularly difficult in the field of neurology because damage to the brain is often permanent and will change a patient’s way of life forever.