May 6, 2008 – Light therapy is known to be effective in many people who suffer from seasonal depression. But it is not yet clear how the brain reacts to artificial light. This is what Montreal researchers who are looking for candidates for a study on the subject will try to determine.
In Nordic countries such as Canada, seasonal depression, which is linked to the lack of natural light during fall and winter, is thought to affect 3% to 8% of the adult population, the majority of which are women.
Light therapy is the best documented treatment for treating seasonal depression. It involves daily exposure to high intensity white light to treat problems associated with lack of sunlight.
“Light therapy is effective in around two out of three patients suffering from seasonal depression,” says researcher Gilles Vandewalle. In their case, the symptoms are reduced by 50% to 80% – which is comparable to antidepressants. “
What parts of the brain react to light?
Doctor in neuroscience and specialist in the effect of light on mood, Gilles Vandewalle will lead a study aimed at determining which parts of the brain react positively or negatively to light.
“We want to verify whether light has an immediate effect on the brain systems, including those that regulate mood or emotions, and by what mechanism it acts,” he explains.
To do this, the research team will need around 40 people, half of whom suffer from seasonal depression. The sessions will take place at the Institut universitaire de gériatrie de Montréal.
First, participants will meet with a psychologist and have to take an optometric examination. Subsequently, they will be subjected to an imaging test (to scan) which will last 45 minutes. This last examination will be used to measure the effect of light beams in different areas of the brain, during two seasons: between the months of May and August, then between the months of November and February.
“We hope to show that people who suffer from seasonal depression will have different brain responses than others in winter. We are going to test different light spectra, including blue and green, ”explains Gilles Vandewalle.
If you would like to participate in this study, leave a message at 514 340-3540 (extension 3367). Remuneration is provided for those selected.
Martin LaSalle – PasseportSanté.net
