# Linguistic and Neural Synchrony During Co-Rumination as Interpersonal Mechanisms of Depression in Adult and Adolescent Dyads > **NIH NIH K99** · NORTHWESTERN UNIVERSITY · 2024 · $111,270 ## Abstract PROJECT SUMMARY/ABSTRACT Interpersonal dysfunction is an intractable problem in depression that strongly predicts depression vulnerability and chronicity. Clarifying markers of interpersonal dysfunction and its biobehavioral mechanisms are prerequisites to developing theoretically based and biologically informed interventions able to improve functional outcomes. An established marker of interpersonal dysfunction is co-rumination–i.e., excessively discussing personal problems and dwelling on negative affect in dyadic relationships–a construct linked to worsened depression severity in both dyadic partners. However, the biobehavioral processes that unfold during co- ruminative interactions remain unclear, precluding the identification of precise intervention targets. The proposed K99/R00 project tests whether temporal alignment (i.e., synchrony) in language and neural oscillations between close friends is a mechanism of co-rumination, given synchrony’s key role in communication and bonding. The overall hypothesis is that linguistic and neural synchrony during a laboratory problem discussion task (K99 and R00) and smartphone communication (R00) mediate the association between co-rumination and depression, using simultaneous dual-subject EEG recordings (hyperscanning) and mobile sensing (to acquire smartphone communication; R00 only). 76 adults (K99; 50% female, 18-40 yrs) and 110 adolescents (R00; 50% female, 14-17 yrs) with major depression and one of their same-sex friends will be recruited. Aims will test whether linguistic and neural synchrony are associated with in-lab co-rumination (Aim 1) and concordance in depression symptoms (Aim 2), as well as whether linguistic synchrony in smartphone communication is associated with in-lab co-rumination and depression (Aim 3). Both the K99 and R00 will additionally explore whether sex moderates the association of synchrony with co-rumination and depression. To achieve these aims, the proposed career development plan will build on Dr. Li’s previous training, with four goals to enhance her trajectory towards becoming an independent investigator: (1) apply multimethod RDoC approaches to studying mechanisms of psychopathology, (2) conduct mobile sensing and dyadic-level natural language processing analysis, (3) conduct EEG hyperscanning and dyadic-level EEG time-frequency analysis, and (4) grantsmanship, lab management, and interdisciplinary collaboration requisite to run a successful, independent laboratory. Training will be accomplished through direct mentorship from experts in developmental psychopathology, neuroscience, and computer science and formal coursework from centers and institutes at Northwestern University. Data obtained in this project will (a) explicate the biobehavioral mechanisms of interpersonal risk factors for depression, (b) lead to future R01 applications on the longitudinal predictive utility of linguistic and neural synchrony for depression, and (c) give Dr. Li the expertise in integr... ## Key facts - **NIH application ID:** 10884620 - **Project number:** 1K99MH133991-01A1 - **Recipient organization:** NORTHWESTERN UNIVERSITY - **Principal Investigator:** Lilian Y. Li - **Activity code:** K99 (R01, R21, SBIR, etc.) - **Funding institute:** NIH - **Fiscal year:** 2024 - **Award amount:** $111,270 - **Award type:** 1 - **Project period:** 2024-05-01 → 2026-04-30 ## Primary source NIH RePORTER: https://reporter.nih.gov/project-details/10884620 ## Citation > US National Institutes of Health, RePORTER application 10884620, Linguistic and Neural Synchrony During Co-Rumination as Interpersonal Mechanisms of Depression in Adult and Adolescent Dyads (1K99MH133991-01A1). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10884620. Licensed CC0. --- *[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*