Rumination Induction Task in fMRI: Test-Retest Reliability in Youth and Potential Mechanisms of Change with Intervention

Background Rumination is a transdiagnostic problem that is common in major depressive disorder (MDD). Rumination Focused Cognitive Behavioral Therapy (RF-CBT) explicitly targets the ruminative habit. This study examined changes in brain activation during a rumination induction task in adolescents with remitted MDD following RF-CBT. We also evaluated the reliability of the rumination task among adolescents who received treatment as usual (TAU). Method Fifty-five adolescents ages 14-17 completed a self-relevant rumination induction fMRI task and were then randomized to either RF-CBT (n = 30) or TAU (n = 25). Participants completed the task a second time either following 10-14 sessions of RF-CBT or the equivalent time delay for the TAU group. We assessed activation change in the RF-CBT group using paired-samples t-tests and reliability by calculating intraclass correlation coefficients (ICCs) of five rumination-related ROIs during each of three blocks for the TAU and RF-CBT groups separately (Rumination Instruction, Rumination Prompt, and Distraction). Results Following treatment, participants in the RF-CBT group demonstrated an increase in activation of the left precuneus during Rumination Instruction and the left angular and superior temporal gyri during Rumination Prompt ( p < .01). The TAU group demonstrated fair to excellent reliability ( M = .52, range = .27-.86) across most ROIs and task blocks. In contrast, the RF-CBT group demonstrated poor reliability across most ROIs and task blocks ( M = .21, range = -.19-.69). Conclusion RF-CBT appears to lead to rumination-related brain change. We demonstrated that the rumination induction task has fair to excellent reliability among individuals who do not receive an intervention that explicitly targets the ruminative habit, whereas reliability of this task is largely poor in the context of RF-CBT. This has meaningful implications in longitudinal and intervention studies, particularly when conceptualizing it as an important target for intervention. It also suggests one of many possible mechanisms for why fMRI test-retest reliability can be low that appears unrelated to the methodology itself. ### Competing Interest Statement The authors have declared no competing interest. ### Clinical Trial NCT03859297 ### Clinical Protocols ### Funding Statement This research was funded by the National Institutes of Mental Health (NIMH; R61MH118060/R33MH118060) awarded to Drs. Scott Langenecker and Edward Watkins. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This study was approved by the Institutional Review Board at the University of Utah I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes These data are from a NIMH-funded study and will be available through the NIMH Data Archive. Data are also available upon request.