Around 60 percent of people with bipolar disorder are first diagnosed with depression. Bipolar disorder and depression demonstrate common clinical symptoms, and it can take up to ten years for patients to receive an accurate bipolar diagnosis.
“These two illnesses are virtually identical except that bipolar individuals also experience mania,” said Mayuresh Korgaonkar, one of the researchers. “This means distinguishing them can be difficult and presents a major clinical challenge as treatment varies considerably depending on the primary diagnosis.”
In the study published in Biological Psychiatry: Cognitive Neuroscience and NeuroImaging, Dr. Korgaonkar and his team imaged the amygdala, the brain’s hub for emotional behavior and motivation, to see how it reacts when a patient made facial expressions that correspond to anger, fear, sadness, disgust, or happiness. They found that the amygdala’s left side is less active in people with bipolar disorder and “less connected with other parts of the brain than in people with depression,” according to ScienceDaily. Overall, this rule was proven to be 80 percent accurate.
There is still more to learn about how bipolar disorder and depression are characterized in imaging scans, and the researchers are currently in phase 2 of the study, which involves a bigger patient cohort.