Depression is not just a state of mind. It is a state of the brain. This is particularly true of people who have Major Depressive Disorder and Bipolar Disorder. The above image compares the activity levels of different areas of a depressed brain versus a healthy brain. Here, a P.E.T. scan (Positive Emission Tomography) is used to produce an image of a cross section of a living human brain. It works by administering a radioactive tracer dye in the blood stream. This tracer, usually FDG (fluorodeoxyglucose), enters neurons just as normal glucose would. When a neuron is active, it burns glucose for energy by metabolizing it and splitting it apart. Because the neuron treats the FDG as regular glucose, it is metabolized as well. The difference is that, once split, the FDG releases radioactive particles that are detected by the P.E.T. machine. After detection is complete, a computer produces an image of brain tissue. Active brain tissue is represent by the colors orange and yellow. Inactive tissue is more green and blue. The difference in images is stark and unsettling. How could someone with Major Depressive Disorder or Bipolar Disorder function and feel good with such a hypoactive brain? Often, the answer is that they don’t. These illnesses are truly brain disorders, and must be understood with that taken into consideration. Of significance, when someone with a depressive disorder responds well to treatment, brain activity begins to normalize as seen with follow-up scans.
Blog posts are written by Shore House members and staff.