Clues to Resistant Depression

Main Category: Depression
Article Date: 06 Oct 2003 - 0:00 PDT


People with treatment-resistant depression have abnormal reactions to mood-inducing cues, brain scans show.

At least a third of people suffering from depression get little help from antidepressant treatments. What makes them different? Tonmoy Sharma, MD, director of the Clinical Neuroscience Research Center in Dartfort, England, looked for clues. Their tool: A sophisticated brain imaging system called functional MRI or fMRI.

In real time, fMRI shows which parts of the brain react to specific cues. Sharma's team used fMRI to scan six women with treatment-resistant depression and six healthy women while they looked at captioned pictures. These pictures are known to elicit both positive and negative emotions.

Among the findings:

An area of the brain called the rostral anterior cingulate is abnormally inactive in depressed patients.

Depressed patients had too little activity in an area of the brain needed to attach appropriate emotional meaning to events.

Depressed patients had different activity in an area of the brain needed to recall personal memories. The area was normal in response to negative cues but underactive in response to positive cues.

Depressed patients had unusual responses in an area of the brain linked to evaluating emotional cues.

In response to positive cues, depressed patients had unusually high activity in an area of the brain linked to feeling sad.

'This is a significant step in unraveling the reasons why these people may not be responding to the antidepressant drugs currently available,' Sharma says in a news release.

The findings appear in the October 15 issue of Biological Psychiatry.

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