Globe and Mail

Depression leaves sufferer at a loss

Restoring blood balance in the brain key to treatment, researcher says

Saturday, May 1, 1999
The Globe and Mail

If you can't lose the blues, it's because you aren't thinking straight.

For the first time, a researcher in Canada has offered an explanation for why people who are very sad or depressed lose the ability to concentrate and think through their problems.

Dr. Helen Mayberg says two parts of the brain work like the ends of a see-saw. When a person is experiencing strong emotions, blood flow increases in the brain's emotional centre, with a corresponding decrease in the area that handles thinking.

But while the balance of the blood flow evens out quickly in healthy people, allowing them to snap out of their muddle, the imbalance persists in people suffering from depression, bringing malaise and loss of appetite.

The finding suggests that treatments could focus on this brain balance and shorten the time it takes to get better, said Dr. Mayberg, who holds the Rotman chair in neuropsychiatry at the University of Toronto and Baycrest Centre.

She also found that drugs such as the antidepressant Prozac and therapy can both help restore the balance.

The study used brain scans showing differences in activity in the limbic area, which registers emotions, and the cortical region, where thoughts are processed.

Scans were taken of eight men and eight women with severe depression and compared with eight other subjects who had no symptoms of depression.

When the healthy people were scanned, they were told to recite the details of an extremely sad experience in their lives.

The patients were in tears within a few minutes, and the brain images showed a reduction of 10 to 15 per cent in blood flow in the thinking region, along with up to 20-per-cent reduction in the area's energy use.

After their sad thoughts stopped, the imbalance disappeared within minutes.

The depressed patients did not recover on their own, but with therapy achieved a balance after two to 15 weeks. Half were given Prozac, while the rest took a placebo. All of them had cognitive therapy, a counselling treatment that trained them to shift their attention away from their mood and develop coping strategies.

The results appear today in the American Journal of Psychiatry.

"What you need to do to get well is decrease the activity in the limbic region in the lower rear of the brain," Dr. Mayberg said in an interview. She said it is not a question of thinking harder, but of refocusing.

She said antidepressants have effects on many parts of the brain and future medications might be designed to home in more directly on this problem.

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