Familiar scents unlock memories in people with depression. Could ‘smell therapy’ help patients?

Repeated research has consistently indicated that individuals experiencing depression encounter difficulties in recalling specific memories. For instance, when presented with the word “party,” they may respond with thoughts like, “I seldom receive invitations to parties.” In contrast, those without depression swiftly recall joyous events associated with the term, like a childhood birthday or recent social gathering.

According to Kymberly Young, an associate professor of psychiatry at the University of Pittsburgh, the issue lies not in the absence of memories among depressed individuals but in their struggle to access these memories. Young and her team may have uncovered a potential solution: their study, recently published in JAMA Network Open, proposes that familiar scents could serve as a catalyst for unlocking memories.

In the research, individuals with depression demonstrated improved recall of specific memories when exposed to familiar scents, such as ground coffee or tobacco, compared to when presented with words related to those smells, like “coffee” or “cigarette.” Young suggests that smell therapy could be a beneficial strategy for individuals with depression to mitigate overthinking.

According to Young, the ability to recall specific memories is linked to enhanced problem-solving skills and emotional regulation. The study involved 32 adults with clinical depression who were tasked with sniffing 24 odor samples ranging from pleasant to unpleasant, such as orange, lavender, whiskey, and shoe polish. Participants were then prompted to share a specific memory associated with the scents. The same exercise was conducted using words describing each smell.

Results indicated that 68% of participants could recall specific memories in response to odors, while only 52% could do so when hearing corresponding words. Additionally, memories triggered by scents were described as more vivid compared to those triggered by words. Young noted that recalling memories through smells felt more like “reliving that memory.”

Furthermore, scents tended to evoke more positive memories than words, although this finding lacked statistical significance. Young’s team is currently investigating the potential link between certain smells and positive memories for individuals with depression. Vidya Kamath, a neuropsychologist at Johns Hopkins Medicine not involved in the study, mentioned that previous research has already established a connection between odor and memory in healthy individuals.