Traumatic Brain Injury in Men Convicted of Sexual Offences

Purpose:

This thesis investigates the prevalence of TBI in men convicted of sexual offences (MCSOs) and MCSOs with Mild Intellectual Disability (MID) or Borderline Intellectual Functioning (BIF). It was hypothesised that TBI would be over-represented in these groups and that risk, offence, and clinical profiles of those with TBI could be differentiated from those without. The thesis also investigates the predictive value of TBI status in relation to treatment outcomes for MCSOs attending the Core Sex Offender Treatment Programme (CSOTP).

Method:

The TBI status, risk, offence, and clinical characteristics of 5,141 MCSOs and 519 MCSOs with MID-BIF were assessed via self-report pre-sex offender treatment. Outcome measures included programme completion and short-term change on psychometrics measuring treatment targets, assessed using statistical group change and a model of clinically significant change.

Results:

TBI was over-represented in both MCSOs and MCSOs with MID-BIF. In MCSOs, TBI was associated with higher risk of sexual recidivism, frequent offending, substance abuse, history of psychological treatment and greater difficulties with impulsivity, problem solving and emotional regulation. These findings were not replicated in MCSOs with MID-BIF. Treatment completion rates did not differ according to TBI status of the MCSOs, but psychometric change did. At a group level, compared to those MCSOs without TBI, those with TBI improved significantly more on 7/13 measures. Individual level comparison revealed a more complex picture, with MCSOs with TBI having more dysfunctional pre-treatment scores and being less likely to achieve clinically significant change on key criminogenic needs. TBI status did not predict clinically significant change category.

Conclusion:

The findings suggest that TBI is over-represented in MCSOs with and without MID-BIF. MCSOs with TBI were characterised by distinct risk, offence, and clinical profiles but MCSOs with MID-BIF and TBI were not. The thesis provides modest evidence in support of MCSOs with TBI benefiting from non-adapted treatment. Opportunities to improve assessment and treatment outcomes are discussed.