Aims:

The aim of the study is to investigate the trajectories of traumatic brain injury (TBI) from childhood into adolescence using the ALSPAC cohort. In particular the study will explore the impact that a single TBI event and recurrent TBI events will have on aspects of social cognition, risk behaviour engagement and general cognition. The control groups will include participants who have had a broken bone/fracture and also participants who have never had an injury. There will be exploratory analyses conducted to see whether the detrimental effects of recurrent TBI events are greater than for a single TBI event.

Social cognition can be broadly conceived as the ability to understand other people through emotion perception and empathy and also by inferring the beliefs, intentions and feelings of others 1 Following a TBI event, many facets of social cognition have been shown to be impaired, such as the recognition of facial emotional expressions 1-4; however, current evidence is hampered by small, heterogeneous sample sizes 1.

Engagement in risky behaviour such as substance use has been implicated as an outcome of TBI 5-8. One large cohort study demonstrated that a TBI injury requiring hospitalisation between the ages of 0-5 years old increases the risk for adolescent substance use 5; while findings from another birth cohort indicate that drinking to intoxication is more common among 14 year olds who have experienced a TBI compared to those who have not 6. Ilie and colleagues 7 found that high school students who had experienced a TBI had higher odds of using illicit substances, were twice as likely to consume hazardous amounts of alcohol and were at greater risk for cannabis dependence. Likewise, in a group of incarcerated youths, those with a TBI history were found to be more likely to engage in risky alcohol and cannabis use as well as weekly use of another illicit drug prior to incarceration; this was also the case for participants reporting multiple TBI events9. In comparison to a single TBI event, individuals who have experience two or more TBI events have reported more frequent alcohol, tobacco and illicit drug use 8.

The sequelae of TBI is characterised by cognitive problems 10. Corrigan and colleagues 11 compared different characteristic profiles of TBI histories in persons with substance use disorders and found that a TBI event occurring between the ages of 6-10 may lead to slower processing speed and a greater number of cognitive complaints, while working memory was more impaired in those with a severe adult TBI, mild adolescent injury or multiple mild injuries. Elsewhere, processing speed has been found to be more impaired in participants with more than one TBI resulting in loss of consciousness than in participants who have had just one TBI 8.

Predictors of TBI from birth cohort studies include male gender 6,12, parental alcohol misuse 6, a punitive parenting style and the number of adverse life events experienced by the family 12. These will be controlled for in the proposed study.