The prevalence, predictors, associated symptoms, and outcomes of social disinhibition following moderate-to-severe TBI: a scoping review of quantitative evidence

The present study aimed to map existing quantitative evidence of research related to the nature of social disinhibition following moderate-to-severe traumatic brain injury (TBI), with a specific focus on its prevalence, predictors, associated symptoms and outcomes in studies that met minimal methodological criteria. We conducted a scoping review of the literature following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) extension for Scoping Reviews (PRISMA-ScR). Seventeen peer-reviewed articles including 1440 participants met the inclusion criteria and were included in the qualitative synthesis. Results of the study indicate that social disinhibition is a common and significant consequence of moderate-to-severe TBI with its prevalence estimates ranging from 21% to 32%. Inappropriate sexual behavior appears to be more prevalent in men and younger survivors. Rule-breaking/perseverative errors in fluency tests are significantly associated with social disinhibition. The perceived burden of caregivers of people with TBI is a very common outcome. An interesting finding was an association between higher social disinhibition and higher emotional empathy levels. However, similarly to many potential predictors, this was only found in a single study and therefore requires further investigation. Some common methodological flaws are discussed, such as the use of non-probability sampling, lack of sample size justification or not including a control group. Due to the heterogeneity of measures used to assess social disinhibition in the reviewed articles, conducting a meta-analysis was not possible. In conclusion, social disinhibition is a significant consequence of moderate-to-severe TBI, as it impacts both the TBI survivor and their family/caregivers. The present study extends the scope of the prior overview by offering a clearer picture of social disinhibition after surviving moderate-to-severe TBI, as it focuses on studies with strong methodology and validated measures. It also assesses potential predictors other than executive dysfunction, such as demographics and injury characteristics.