Thursday, 2 April 2009

A Neuroimaging Revolution

Neuroimaging has indeed revolutionized and continues to revolutionize our understanding of mental disorders, because it is based on learning about how the brain grows, develops and functions.

This is so far removed from earlier ideas about how “society” or “the environment” or “culture” or “religion” or “monsters” created mental illness, that some people whose beliefs or other investments are in these explanations will have problems accepting its value. When linked to other new tools of understanding such as genetics and molecular biochemistry, we are beginning to learn how the brain functions in health, when it is challenged by the environment and in disease.

The recent article in the Globe and Mail by Elizabeth Scott brings to life the importance of this technologically enabled explosion in understanding. She shows us how valuable this harnessing of new methodologies can be as we pull away the shrouds of uncertainty and begin to lift the veil of confusion caused by centuries of invalidated explanations of why mental illness occurs.

The real challenge however will be in changing our perspective based on new knowledge.Simply put, old ideas die hard and the new understanding will be strongly resisted by those who either do not or will not wish to be informed. On the other hand, this new information will need to stand the rigorous and unfriendly critical scrutiny of science, as different researchers conduct different studies and argue about what their results mean. This is a messy business and science is not about “the truth”. It is merely about being less wrong, most of the time.

All of which brings me to an exciting study recently published in the Proceedings of the National Academy of Sciences which demonstrated an almost 1/3 reduction in the right cerebral cortex (the outer cell layer on the right side of the brain) in the brains of people who have a family history of depression. These changes were associated with a number of difficulties in thinking and when the left side showed thinning, these difficulties became part of the syndrome of what we call major depression.
To me, these findings suggest that depression (at least the type that runs in families) may be a degenerative brain disorder. That’s right, a degenerative disorder – much like Parkinson’s disease or Alzheimer’s disease. And the thinking problems that we have noticed in people with depression may not be the result of the mood problem but may actually be part of the same disease process that gives rise to the depressed mood. That is, our theories that negative thoughts cause depression are likely wrong. Both the mood problem and the thinking problems are due to the same disease process in the brain.

This finding supports observations that many researchers and clinicians have been making for years. And, this finding suggests that we may have to change how we search for better treatments for depression. Maybe we should be looking at medications that can arrest brain degeneration or maybe we should be looking at medications that can improve cognition.Whatever the outcomes, these findings are exciting, offer new hope for future research and challenge what we “believe” to be true. Stay tuned – the story will unfold as it should!

~ Dr. Stan Kutcher

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