Posted by Blog Administrator June 18, 2012
Sherbet orange and yellow, greens as bright as the fuzz on a tennis ball, blues reminiscent of a setting sky – all splattered across a soft gray maze. It’s not a Claude Monet painting. These colors exist on imaging scans produced by sophisticated machines in the Functional Neuroimaging Laboratory (FNL) at Brigham and Women’s Hospital (BWH), directed by Dr. Emily Stern of the Department of Radiology. Stern and FNL researchers are studying images of the human brain to uncover the mysteries of depression, schizophrenia, and other mental disorders.
With advanced tools that may change the medical landscape of psychiatry, one of the most poignant ambitions that the researchers have is to erase the stigma surrounding mental illness.
“Seeing a picture of brain areas lighting up abnormally on an MRI conveys that there is a biological problem with the brain in people with mental disorders,” says Dr. Stern. “We hope that when people hear that mental disorders have a biological basis, they will think of these disorders differently, and not as something that a person can just snap out of. These are true disorders of the brain, just like there are disorders of the heart, kidney, or lung. And we are just starting to understand the neurobiology behind this.”
The researchers are using a tool called functional magnetic resonance imaging (functional MRI) to view the brain activity of mentally ill patients. When a patient’s brain is stimulated – for instance by watching a series of photographs flash on a monitor – some parts of the brain work harder than others to do the specific task. The harder-working areas need more oxygen, and functional MRI detects associated levels of deoxygenated blood in these regions. The different levels produce the array of colors on a scan and allow the researchers to view active brain areas.
Although there is still much to learn, the researchers have already made some intriguing discoveries.
For instance, compared to healthy people, those with depression cannot activate a part of their brain called the ventral striatum, which is responsible for processing positive emotions. On a functional MRI scan, this area does not light up in depressed patients, but does light up in healthy subjects in response to stimuli with positive content.
The researchers are also using functional MRI to study the overlap of symptoms across different disorders.
For example, irritability and impulsivity, two symptoms of premenstrual dysphorphic disorder (a condition that causes severe emotional and physical problems and is linked to the menstrual cycle) also exist in patients with borderline personality disorder. When looking at the scans of patients with these disorders, both groups share an abnormality in the brain’s frontal lobe – the “control tower” responsible for keeping emotions in check.
“In borderline personality disorder and premenstrual dysphorphic disorder, there are similar symptoms. You have the same inability to control behavior and negative emotions,” said Stern. “We are starting to paint the picture, but still filling in the spaces.”
Unlike other medical fields where doctors diagnose diseases based on biological evidence, mental health professionals make their diagnoses based on observing patient behavior and assessing reported symptoms.
“We want to use imaging tools as objective biomarkers that can help in the diagnosis,” says Dr. Stern.
She also believes that these tools may guide treatment.
“This is important because, typically, it can take up to six weeks to know if a medication that is prescribed for a certain psychiatric disease is effective for that patient. If it isn’t, then the patient has been suffering for those six weeks, and you have to start over,” notes Dr. Stern. But Dr. Stern hopes to change that. In the ideal patient encounter, she explains, doctors would be able to confidently predict whether a treatment will work without this trial-and-error period.
“With imaging tools, we are hoping that we can do a type of functional scan to see a patient’s brain pattern activity,” says Dr. Stern. “From that, we could determine how likely a patient is to respond to a certain medication or behavioral intervention.”