TORONTO, ONT. -- A Toronto neurologist has found an important clue in the brain that may explain why some people respond better to an anti-depressant than others. The discovery is an important step in the development of more effective and faster-acting treatments for depression.
The clinical study, to be published in the October 15th, 2000 issue of the international journal Biological Psychiatry, looked at why there is often a delay of several weeks before an anti-depressant starts to make a person feel better AND what has to change in the brain over time in order to get well.
It's the first study to zone in on the 'timing' of changes taking place in brain regions during drug treatment. It's also the first to identify brain areas that appear to be critical to illness remission in that they behave like a "switcher" in a railway yard -- deciding what track a train will take.
Dr. Helen Mayberg, with her colleagues Drs. Steven Brannan, Janet Tekell and Arturo Silva, conducted the study at the Research Imaging Centre, a specialized research facility at The University of Texas Health Science Centre at San Antonio. Dr. Mayberg is now with Toronto's Rotman Research Institute at Baycrest Centre for Geriatric Care.
In the double blind study, 15 male veterans diagnosed with severe depression at a San Antonio hospital were given either a standard dose of the anti-depressant fluoxetine (trade name Prozac), or a placebo. Of the 10 who received Prozac, all showed a similar pattern of brain changes at the end of the first week of treatment, but none felt any better. By the end of six weeks of treatment, only four of the men were responding well to treatment and feeling better.
Using positron emission tomography -- which constructs computerized multi-colored images showing where maximum activity (glucose metabolism) is occurring in the brain -- the research team identified 'distinct differences' in the change pattern in brains of responders compare
Contact: Kelly Connelly, Media Relations