"For the first time, our study supports the idea that there may be on-going damage to certain regions of the brain as the illness progresses," said the study's lead author Raymond Deicken, MD. Deicken is the medical director of the Psychiatric Partial Hospital Program at the San Francisco VA Medical Center and UCSF associate professor of psychiatry.
The study appears in the May issue of the American Journal of Psychiatry.
More than 2 million Americans suffer from bipolar disorder, commonly known as manic depression. To date, there are no physiological markers used to diagnose the disease. Instead, it is identified by behavioral symptoms, including frequent mood swings between high-energy mania and severe depression.
Deicken and his colleagues compared brain scans of 15 non-symptomatic male patients with familial bipolar I disorder to those of 20 healthy male comparison subjects. Male subjects were chosen to control for the effects of gender. In addition, test subjects were chosen based on several previous studies showing that patients who have inherited the disorder have more prominent changes in brain structure and function.
Researchers determined chemical signatures of different brain structures in these two groups using proton magnetic resonance spectroscopy. One finding focused on the level of an amino acid called N-acetylaspartate, or NAA, in the hippocampus, which is made up of a right and left half and is part of a complex of neural circuits in the brain that regulate emotion and memory.
The study found significantly lower concentrations of NAA in the right hippocampus of males with bipolar disorder when compared to the control group. They also found that for the right hippocampus, bipolar patients who had the disease the longest had the lowest levels of the amino a
Contact: Camille Mojica Rey
University of California - San Francisco