Transdiagnostic MRI Markers of Psychopathology following Traumatic Brain Injury: A Systematic Review and Meta-Analysis Protocol

IntroductionPsychopathology following traumatic brain injury (TBI) is a common and debilitating consequence that is often associated with reduced functional and psychosocial outcomes. There is a lack of evidence regarding the neural underpinnings of psychopathology following TBI, and whether there may be transdiagnostic neural markers that are shared across traditional psychiatric diagnoses. The aim of this systematic review and meta-analysis is to examine the association of MRI-derived markers of brain structure and function with both transdiagnostic and specific psychopathology following moderate-severe TBI. Methods and analysisA systematic literature search of Embase (1974-2022), Ovid MEDLINE (1946-2022) and PsycINFO (1806-2022) will be conducted. Publications in English that investigate MRI correlates of psychopathology characterised by formal diagnoses or symptoms of psychopathology in closed moderate-severe TBI populations over 16 years of age will be included. Publications will be excluded that: a) evaluate non-MRI neuroimaging techniques (CT, PET, MEG, EEG); b) comprise primarily a paediatric cohort; c) comprise primarily penetrating TBI. Eligible studies will be assessed against a modified Joanna Briggs Institute Critical Appraisal Instrument and data will be extracted by two independent reviewers. A descriptive analysis of MRI findings will be provided based on qualitative synthesis of data extracted. Quantitative analyses will include a meta-analysis and a network meta-analysis where there is sufficient data available. Ethics and disseminationEthics approval is not required for the present study as there will be no original data collected. We intend to disseminate the results through publication to a high-quality peer-reviewed journal and conference presentations on completion. PROSPERO registration numberCRD42022358358 Article SummaryStrengths and limitations of this study: O_LIThis is a comprehensive review of MRI markers of psychopathology among adults with moderate - severe traumatic brain injuries. C_LIO_LIWe will investigate neural correlates across the spectrum of psychopathology rather than focusing on specific diagnoses, allowing for transdiagnostic investigations of brain structure and function alterations after TBI with comorbid psychopathology. C_LIO_LIWe will be restricting eligible studies to English language. C_LIO_LIWe will capture pre-injury psychopathology where data are available and analyse the associations with post-injury psychopathology and neural correlates. C_LI