Smelling familiar odors could help improve mood in people suffering from major depression, a new study suggests.
Neuroscientists from the University of Pittsburgh found that patients who sniffed 12 recognizable scents had better access to positive memories – stopping negative thought patterns that perpetuate the mental illness.
The participants recalled specific memories from their lives when they smelled Vicks Vaporub, coffee, vanilla extract, lavender hand soap, and more common household items.
Problems with autobiographical memory are a hallmark of major depressive disorder, which often lulls patients into focusing only on negative events or interpreting events in a negative light.
The scientists say that by helping depressed individuals access their memories more effectively with smell, negative thought cycles can be intercepted.
Coffee is among one of 12 different smells found to evoke memories, which can change negative thought patterns, researchers suggest
Each smell presented to the participants were paired with a corresponding word. For instance, the word corresponding to cumin powder was ‘curry’. Researchers found that the smells, not the words, evoked the most vivid autobiographical memories
For their study, neuroscientists enrolled 32 people aged 18-55 with major depression. They were exposed to 12 smells in airtight jars along with a written clue as to the scent.
Scents included coconut oil, cumin powder, clove bulbs, red wine, wax shoe polish, vanilla extract, ketchup, and orange essential oil.
Eyes closed, they took a whiff from each jar and were asked to consider a memory sparked by the smell.
Each participant rated memories on how good or bad it made them feel, how exciting it was, how clear it was, and how often they thought about it. They were then asked to identify each scent but were told it wasn’t important to get it right.
Participants identified the smells correctly about 29 percent of the time on average. Smells evoked more specific memories from their lives than word cues. For instance, hearing the word ‘menthol’ was far less evocative than opening a jar and smelling Vicks Vaporub.
Smell-triggered memories tended to be more emotionally arousing, vivid, and took longer to recall than word-triggered memories.
The researchers said: ‘Odor-evoked memories may be unique relative to other stimuli, such as auditory and visual, and contain emotionality.’
The olfactory bulb, responsible for processing smells, directly connects to key brain regions associated with memory and emotion, such as the amygdala and hippocampus.
Unlike other senses, smells can directly access the emotional part of the brain, which experts believe may explain why smells have such a profound impact on our memories and emotions.
Dr Kymberly Young, neuroscientist and co-author of the study, said: ‘If we improve memory, we can improve problem solving, emotion regulation and other functional problems that depressed individuals often experience.’
There are some approaches to treating depression that include scent to evoke positive memories.
Therapists may include aromatherapy as part of their normal cognitive behavioral therapy practice that trains depressed people to rethink their negative thought patterns.
They may also try what is known as reminiscence therapy, which involves recalling and sharing past experiences facilitated by sensory stimuli such as smells, photos, or music. The idea is that by tapping into positive memories and emotions, reminiscence therapy can improve mood, self-esteem, and overall well being.
The findings were published in the journal JAMA Network Open.
