Testing changes in olfactory processing as a biomarker of mood disorders- a multidisciplinary study

That first whiff of coffee perks up your senses. The smell of mom’s cooking transports you back to childhood. Though we often take it for granted, the human sense of smell has a unique role, with special links in the brain to our memories and emotions. People suffering from depression may experience problems with their olfactory, or odor, function, like reduced sensitivity to smells and an inability to enjoy those normally considered pleasant. Olfaction is also one of the fastest ways that vital environmental information reaches the brain—about availability of food, danger (imagine a gas leak) and social cues, for example—allowing us to react quickly, whether consciously or not. Losing this ability, as in depression, adds a further behavioral handicap in an already disabling condition.
Dr. Kalliopi Apazoglou is investigating the underexplored relationship between mood disorders and the brain’s olfactory system. Since feelings and smells have been shown to activate the same brain areas, she wants to know if a malfunction in these regions during a mood disorder causes changes in odor perception. Her preliminary data from imaging patients’ brains shows that when people with high depression scores smell different scents, there is less activity than normal in a specific brain region, as if its response to odors is blunted. But do parallels exist between olfactory function, personality traits and emotional state? To find out, she is measuring people’s reactions to different odors and correlating them with the results of behavioral questionnaires. She has found, for instance, that anxiety and emotional reactivity have a significant impact on the way people rate the pleasantness of odors, intensifying how much they like or dislike a scent. Dr. Apazoglou’s research aims at unraveling the mechanisms underlying olfaction and mood disorders. She hopes to contribute to both the prevention and diagnosis of depression, a condition that strikes up to 20% of the world’s population.