JAMA Network Open: Recall of Autobiographical Memories Following Odor vs Verbal Cues Among Adults With Major Depressive Disorder

Major depressive disorder (MDD) is a pervasive and common illness that can severely diminish individuals’ quality of life. Among the challenges associated with major depressive disorder, individuals with MDD may have trouble recalling specific memories (a memory of a single event occurring at a specific place and time) in favor of categorical memories (a generalized memory encompassing several distinct episodes). Patients with MDD may get stuck recalling overly general self-knowledge statements like “I am a failure” or “I fight with my friends a lot,” rather than specific memories of events.

When using stimuli to prompt autobiographical memory recollection, odor-evoked memories—vs. memories following auditory and visual stimuli—can yield an especially emotional response due to the unique neuroanatomy of olfactory processing in the brain. The olfactory bulb, responsible for processing odor information, directly projects to several parts of the brain implicated in memory and emotion, including the amygdala and hippocampus. 

Investigators including Emily Leiker, PhD (postdoctoral scholar); Laurie Compere, PhD (Research Instructor in Psychiatry); and Kymberly Young, PhD (Associate Professor of Psychiatry), from Pitt Psychiatry, conducted a cross-sectional study on the use of odor cues to evoke specific memories, compared with verbal cues.

Participants comprised 32 adults with major depressive disorder who were presented with a series of either odor or word cues and asked to recall a specific memory in response to each cue. Memories were then coded by the experimenter according to their level of specificity.

The scientists found that participants with major depressive disorder recalled more specific autobiographical memories when cued with odors, compared with word cues. Notably, increased memory specificity occurred even when participants experienced difficulty identifying the odors presented. The findings were recently published in JAMA Network Open.

“These findings suggest that it’s not the case that depressed individuals don’t have specific memories—it’s that they have trouble accessing them, and odors may improve access to these memories,” said Dr. Young, the study’s corresponding author. “If we can improve specific memory recall, we should also improve problem solving, emotion regulation, and other functional problems that depressed individuals often experience.” 

Recall of Autobiographical Memories Following Odor vs Verbal Cues Among Adults with Major Depressive Disorder
Leiker EK, Riley E, Barb S, Lazzaro SK, Compere L, Webb C, Canovali G, Young KD.
JAMA Network Open. 2024;7(2):e2355958. doi:10.1001/jamanetworkopen.2023.55958