Indeed, despite years of work, neuroscientists still do not know what causes bipolar disorder, or exactly which parts of the brain are involved. That lack of knowledge has severely hampered the search for safer and more effective ways to treat the disease. The principal drugs for bipolar disorder, lithium and Depakote, have been around for decades.
Both were discovered by accident, when researchers trying to do something else noticed that the drugs eased the symptoms of patients with bipolar disorder. And though the drugs can be reasonably effective in some people, doctors have no idea how they work or which patients are most likely to benefit. In order to find better pharmaceuticals, researchers need to be able to target the exact mechanisms or structures involved in bipolar disorder.
Pinpointing the mechanisms could also lead to more accurate evaluation of the disorder. Often, diagnosis in psychiatry is done by a kind of trial and error, in which a psychiatrist makes an educated guess based on the behavior or self-reported symptoms of a patient, prescribes a medication, and sees whether or not it helps. If it doesn’t, the psychiatrist considers a different diagnosis and a different medication, until something begins to work.
“What psychiatrists need is some test that will give them the answer: this patient has the disease or doesn’t,” says Port. He and other researchers hope MRI scanners will offer the definitive diagnosis. And for those in the mental-health profession, that would change everything. “I’m dedicating the rest of my career to coming up with an imaging test that will help psychiatrists diagnose” bipolar disorder and other illnesses, Port says.
Tomorrow: A deeper look at the technologies of MRI spectroscopy and DTI.
Paul Raeburn’s most recent book is Acquainted with the Night, a memoir of raising children with depression and bipolar disorder.
Home page image courtesy of John Port.