Honors & Awards


  • Rising Star Showcase, Society of Biological Psychiatry (04/2026)
  • Early Career Membership Award, Anxiety and Depression Association of America (04/2026)
  • Travel Award, Social Affective Neuroscience Society (04/2024)

Professional Education


  • Ph.D., University of Pennsylvania, Psychology
  • B.A., Korea University, Psychology, Brain and Cognitive Sciences

Stanford Advisors


Community and International Work


  • Global Initiative on Loneliness and Connection

    Location

    International

    Ongoing Project

    No

    Opportunities for Student Involvement

    No

Current Research and Scholarly Interests


My research focuses on translating neuroscience into real-world solutions by leveraging brain function as a biomarker to advance precision in depression treatment and develop personalized approaches to mental and behavioral health care.

All Publications


  • Developing Clinically Interpretable Neuroimaging Biotypes in Psychiatry. Biological psychiatry Ahn, J., Foland-Ross, L., Akiki, T. J., Boyar, L., Wydler, I., Bostian, C., Zhang, X., Yang, H. J., Ellsay, A., Ma, E., Rajasekharan, D., Holtzheimer, P., Lim, K., Madore, M., Philip, N., Ajilore, O., Ma, J., Williams, L. M. 2025

    Abstract

    Despite available treatments, major depressive disorder (MDD) remains one of the leading causes of disability across medical conditions. The current symptom-based diagnostic system groups patients with highly heterogeneous presentations, with no biomarkers to guide treatment-akin to diagnosing heart disease solely by chest pain, without imaging to reveal the underlying pathology. Lacking biological guidance, clinicians rely on trial-and-error prescribing. Only 33% of individuals with MDD achieve remission on initial treatments, and most cycle through multiple treatments over an average of seven years. The risk of relapse increases with each treatment failure, rising from 50% to 90%. This critical review synthesizes studies showing how functional MRI (fMRI) can predict treatment outcomes and identify which treatment is most effective for an individual based on their brain circuit profile. We illustrate one such method: a theoretically informed approach that quantifies dysfunction across six large-scale brain circuits, relative to healthy reference norms. The resulting personalized circuit scores serve as predictors of response or failure and as moderators of differential treatment outcomes. Matching treatment to a patient's biotype, defined by their circuit profile, has the potential to double remission rates compared to unmatched treatment. We place this example in the broader context of precision imaging approaches to parsing MDD heterogeneity. We also discuss key challenges, limitations, and future directions for translating fMRI-based tools into clinical practice.

    View details for DOI 10.1016/j.biopsych.2025.08.019

    View details for PubMedID 40930375

  • Personalized Treatment Selection in Depression Using Clinically Interpretable Neuroimaging Biotypes Ahn, J., Foland-Ross, L. C., Zhang, X., Ellsay, A., Akiki, T. J., Rajasekharan, D., Holtzheimer, P., Lim, K., Madore, M. R., Philip, N. S., Ajilore, O., Ma, J., Williams, L. M. ELSEVIER SCIENCE INC. 2026
  • Brain activity explains message effectiveness: A mega-analysis of 16 neuroimaging studies. PNAS nexus Scholz, C., Chan, H. Y., Ahn, J., Boksem, M. A., Cooper, N., Coronel, J. C., DorĂ©, B. P., Genevsky, A., Huskey, R., Kang, Y., Knutson, B., Lieberman, M. D., Brook O'Donnell, M., Resnick, A., Smidts, A., Venkatraman, V., Vo, K., Weber, R., Yoon, C., Falk, E. B. 2025; 4 (11): pgaf287

    Abstract

    Persuasive communication in marketing, political, and health domains influences sales, elections, and public health. We present a mega-analysis (a pooled analysis of raw data) of 16 functional MRI datasets (572 participants, 739 messages, and 21,688 experimental trials) assessing the neural correlates of the effectiveness of messages in individual message receivers and at scale (in large groups of message receivers who did not undergo neuroimaging). Existing theories suggest that decision-making is driven by expected rewards and perceived social relevance associated with the expected outcomes of a given choice. Consistent with these theories, we find that (i) brain activity implicated in reward and social processing is associated with message effectiveness in individuals and at scale across diverse domains (e.g. marketing and health campaigns); (ii) exploratory analysis further suggests language, emotion, and sensorimotor processes as pertinent to message effectiveness; and (iii) brain activity provides complementary information on message effectiveness at scale beyond self-reports provided by the same neuroimaging participants. This study offers novel insights into the neurocognitive mechanisms underlying effective messaging, highlights a path toward greater unity and efficiency in persuasion research, and suggests practical intervention targets for message design.

    View details for DOI 10.1093/pnasnexus/pgaf287

    View details for PubMedID 41200100

    View details for PubMedCentralID PMC12586322

  • Baseline Physical Activity Moderates Brain-Behavior Relationships in Response to Framed Health Messages. Social cognitive and affective neuroscience Ahn, J., Cooper, N., Kang, Y., O'Donnell, M. B., Green, M. A., Notthoff, N., Carstensen, L. L., Samanez-Larkin, G. R., Falk, E. B. 2025

    Abstract

    Health messaging often employs gain-framing (highlighting behavior benefits) or loss-framing (emphasizing non-engagement risks) to promote behavior change. This study examined how neural responses to gain- and loss-framed messages predict changes in physical activity. We conducted a mega-analysis of raw fMRI and pedometer/accelerometer data from four studies (N = 240) that tracked brain activity during message exposure and real-world physical activity longitudinally. Focusing on brain regions theorized by the Affect-Integration-Motivation (AIM) framework-the anterior insula, ventral striatum, vmPFC, dorsal striatum, and pre-SMA-we found that baseline physical activity levels moderated brain-behavior relationships in response to message framing. More active individuals increased physical activity post-intervention when these brain regions responded more strongly to loss-framed messages, suggesting that neural sensitivity to inactivity risks may reinforce behavior maintenance in this group. Conversely, less active individuals increased physical activity when brain responses were stronger to gain-framed messages, indicating that sensitivity to activity benefits may facilitate action initiation in this group. These findings suggest that message effectiveness depends on the interaction between framing, neural processing, and pre-existing behavioral patterns. By linking neurocognitive mechanisms with real-world outcomes, we highlight the importance of personalized, neuroscience-informed health interventions tailored to individual neural and behavioral characteristics to optimize behavior change strategies.

    View details for DOI 10.1093/scan/nsaf046

    View details for PubMedID 40324902

  • Relationships between physical activity and loneliness: A systematic review of intervention studies CURRENT RESEARCH IN BEHAVIORAL SCIENCES Ahn, J., Falk, E. B., Kang, Y. 2024; 6