Scents May Improve Memory in Major Depression

TOPLINE:

Scents that trigger specific, vivid autobiographical memories (AMs) could improve deficits in memory recall in patients with major depressive disorder (MDD), new research suggests. Investigators found that odor cues may be a stronger tool than word cues for improving memory, which could help reduce MDD symptoms.

METHODOLOGY:

• Participants included 32 individuals aged 18-55 years (mean age, 30 years; 26 females) with a diagnosis of MDD recruited from the community.
• Those with psychosis, bipolar I or II, neurological disorders, or drug or alcohol abuse were excluded.
• Participants were presented with a series of 12 words and 12 odors, such as cough syrup, tobacco ash, and Vicks VapoRub, and asked to recall a specific memory in response to each cue.
• AMs were rated in terms of vividness, frequency, and whether they were associated with positive or negative emotions.

TAKEAWAY:

• Although participants only guessed correct stimulus odors 30% of the time, they recalled more specific memories from odor cues than from word cues (68% vs 52%; P < .001).
• Odor-cued recall was more arousing and vivid (P < .001) than recall responses generated by word cues.
• Compared with the population mean for responses to word cues in healthy controls, study participants recalled fewer specific memories in response to words (P < .001), but the percentage of specific memories recalled in response to odor cues did not differ from the healthy control population mean.
• Investigators hoped to further their research by investigating the mechanisms underlying odor-cued AMs, particularly to test if the amygdala and hippocampus are activated during recall.

IN PRACTICE:

“This study suggests the potential for increasing autobiographical memory specificity in individuals with MDD, with the future goal of reducing depression symptoms for this population and informing a better understanding of the neural mechanisms influencing odor-based AM recall,” the authors wrote. “We hope this initial study spurs larger studies in more diverse samples that include healthy control participants to further investigate and explain these associations.”

SOURCE:

Kymberly D. Young, PhD, of the University of Pittsburgh, Pennsylvania, led the study, which was published online on February 13, 2024, in JAMA Network Open.

LIMITATIONS:

Study limitations included the lack of a healthy control group and the small sample size.

DISCLOSURES:

The study was funded internally by the University of Pittsburgh School of Medicine, Pennsylvania. No disclosures were reported.

A version of this article appeared on Medscape.com.