Your brain is a lot like your DNA. It is, arguably, everything that makes you uniquely you. Some types of brain scans are a lot like DNA tests. They may reveal what diseases you have (Parkinson’s, certainly; depression-possibly), what happened in your past (drug abuse, probably; trauma, maybe), or even what your future may hold (Alzheimer’s, likely; response to treatment, hopefully). Many people are aware—and properly protective—of the vast stores of information contained in their DNA. When DNA samples were collected in New York without consent, some went to great lengths to have their DNA expunged from databases being amassed by the police.
Fewer people are aware of the similarly vast amounts of information in a brain scan, and even fewer are taking steps to protect it. My colleagues and I are scientists who use brain imaging (PET and fMRI) to study neuropsychiatric diseases. Based on our knowledge of the technologies we probably ought to be concerned. And yet, it is rare that we discuss the ethical implications of brain imaging. Nevertheless, by looking closely, we can observe parallel trends in science and science policy that are refining the quality of information that can be extracted from a brain scan, and expanding who will have access to it. There may be good and bad reasons to use a brain scan to make personalized predictions. Good or bad, wise or unwise, the research is already being conducted and the brain scans are piling up.
PET (Positron Emission Tomography) is commonly used, clinically, to identify sites of altered metabolism (e.g., tumors). In research, it can be used to identify molecular targets for treatment. A recent PET study of brain metabolism in patients with mild cognitive impairment predicted who would develop Alzheimer’s disease. In our work at Yale, we have used PET images of a medication that targets an opioid receptor to predict which problem drinkers would reduce their drinking while on the medication.