Traumatic brain injury (TBI) may lead to impairments in various outcome domains. Since most instruments assessing these are only available in a limited number of languages, psychometrically validated translations are important for research and clinical practice. Thus, our aim was to investigate the psychometric properties of the patient-reported outcome measures (PROM) applied in the CENTER-TBI study. The study sample comprised individuals who filled in the six-months assessments (GAD-7, PHQ-9, PCL-5, RPQ, QOLIBRI/-OS, SF-36v2/-12v2). Classical psychometric characteristics were investigated and compared with those of the original English versions. The reliability was satisfactory to excellent; the instruments were comparable to each other and to the original versions. Validity analyses demonstrated medium to high correlations with well-established measures. The original factor structure was replicated by all the translations, except for the RPQ, SF-36v2/-12v2 and some language samples for the PCL-5, most probably due to the factor structure of the original instruments. The translation of one to two items of the PHQ-9, RPQ, PCL-5, and QOLIBRI in three languages could be improved in the future to enhance scoring and application at the individual level. Researchers and clinicians now have access to reliable and valid instruments to improve outcome assessment after TBI in national and international health care.

Early exposure to negative environmental impact shapes individual behavior and potentially contributes to any mental disease. We reported previously that accumulated environmental risk markedly decreases age at schizophrenia onset. Follow-up of matched extreme group individuals (≤1 vs. ≥3 risks) unexpectedly revealed that high-risk subjects had >5 times greater probability of forensic hospitalization. In line with longstanding sociological theories, we hypothesized that risk accumulation before adulthood induces violent aggression and criminal conduct, independent of mental illness. We determined in 6 independent cohorts (4 schizophrenia and 2 general population samples) pre-adult risk exposure, comprising urbanicity, migration, physical and sexual abuse as primary, and cannabis or alcohol as secondary hits. All single hits by themselves were marginally associated with higher violent aggression. Most strikingly, however, their accumulation strongly predicted violent aggression (odds ratio 10.5). An epigenome-wide association scan to detect differential methylation of blood-derived DNA of selected extreme group individuals yielded overall negative results. Conversely, determination in peripheral blood mononuclear cells of histone-deacetylase1 mRNA as 'umbrella mediator' of epigenetic processes revealed an increase in the high-risk group, suggesting lasting epigenetic alterations. Together, we provide sound evidence of a disease-independent unfortunate relationship between well-defined pre-adult environmental hits and violent aggression, calling for more efficient prevention.

Assessing outcomes in multinational studies on traumatic brain injury (TBI) poses major challenges and requires relevant instruments in languages other than English. Of the 19 outcome instruments selected for use in the observational Collaborative European NeuroTrauma Effectiveness Research in TBI (CENTER-TBI) study, 17 measures lacked translations in at least one target language. To fill this gap, we aimed to develop well-translated linguistically and psychometrically validated instruments. We performed translations and linguistic validations of patient-reported measures (PROMs), clinician-reported (ClinRO), and performance-based (PerfO) outcome instruments, using forward and backward translations, reconciliations, cognitive debriefings with up to 10 participants, iterative revisions, and international harmonization with input from over 150 international collaborators. In total, 237 translations and 211 linguistic validations were carried out in up to 20 languages. Translations were evaluated at the linguistic and cultural level by coding changes when the original versions are compared with subsequent translation steps, using the output of cognitive debriefings, and using comprehension rates. The average comprehension rate per instrument varied from 88% to 98%, indicating a good quality of the translations. These outcome instruments provide a solid basis for future TBI research and clinical practice and allow the aggregation and analysis of data across different countries and languages.