Smelling a familiar scent can help someone who is depressed recall repressed memories, giving them a better chance to recover.
The observation comes from a new small, cross-sectional study published in JAMA Network Open by University of Pittsburgh School researchers and social workers.
The study showed that scents are more effective than words at triggering a person’s memory of a specific event. It also revealed that scents could be used in clinical settings like therapy as a way to help people with major depressive disorder work through negative thought cycles and rewire their thought patterns, aiding in faster and smoother healing.
How does this happen?
It’s all about the amygdala, said Kymberly Young, a neuroscience researcher and the study’s senior author. The amygdala is often referred to as the reptilian part of the brain that controls our body’s fight-or-flight responses. It also makes a person pay attention, focus on important events, and recall memories. Research shows that depressed people may have difficulty recalling specific memories. Healthy people don’t typically have as much difficulty, especially when familiar scents are involved, likely because scents engage the amygdala.
Think of how the smell of apple pie in the oven can take you back in time, perhaps to a Thanksgiving dinner as a child when you tried the dessert for the first time. That process happens because of the amygdala.
Until Ms. Young’s study, research hadn’t delved into how the olfactory senses might be utilized for treating depressed people.
“It was surprising to me that nobody thought to look at memory recall in depressed individuals using scent cues before,” Ms. Young said in a press release.
Strong Scents Elicit Strong Memories
In the University of Pittsburgh study, Ms. Young and her team worked with 32 adults who had been diagnosed with major depressive disorder. Most (over 81 percent) were female, and the average age was 30. Study participants were divided into two groups and presented with 24 words or scents, such as oranges, ground coffee, cloves, scotch whiskey, tobacco ash, and Vicks VapoRub. They were asked to recall memories when presented with the word or scent.
The research team found that participants had stronger memory recall when presented with a scent than when presented with the word representing the scent. Those who received scents were more likely to recall a memory of a specific event than a general one, and they were also more likely to remember positive memories than negative ones.
“If we improve memory, we can improve problem solving, emotion regulation and other functional problems that depressed individuals often experience,” Ms. Young said in a press release.
Olfactory Cues Could Help Treat Depression
The National Institute of Mental Health reports that major depressive disorder is one of the most common mental health conditions in the United States. Major depressive disorder includes symptoms of depressed mood and loss of interest in previously favored activities persisting for at least two weeks. The symptoms are often so severe they affect daily life. Often, people with major depressive disorder struggle with memory recall. In fact, the University of Pittsburgh researchers noted that impaired memory recall represents a key feature of the disorder and suggested it could even potentially cause the disorder.
Medication and psychotherapy treatment are the two go-to forms of treatment for depression. Psychotherapy focuses on helping a person struggling with depression identify their emotions, thoughts, or behaviors. It often also involves digging into the root of the troubling emotion and can include recalling painful or traumatic memories.
Using scents to evoke memories in those with major depressive disorder may be a helpful method to incorporate into therapy. It is common for individuals with depression to get stuck overgeneralizing about themselves in negative ways, using statements like, “I am a failure” or “I fight with my friends a lot,” Ms. Young and her team wrote. Recalling memories, especially positive ones, could help patients break the cycle of negativity and also facilitate healing by confronting troubling memories.
“Odor cues are consistently found to evoke memories that are more emotionally arousing and associated with stronger feelings of reliving than memories evoked by words,” the researchers wrote.