WITHDRAWN: The Relationship of Lifetime Traumatic Brain Injury with Drug Use and Delinquency in the Year Prior to Incarceration: A Propensity Score-Matched Analysis of Incarcerated Youth in Two States

Purpose: Traumatic brain injury (TBI) disproportionately impacts incarcerated youth. TBI is associated with a variety of deleterious outcomes, including violence, substance abuse, depression, suicide, and victimization. Existing research has shown that youth with TBI are more likely to present with unique characteristics such as being a person of color, male, low socioeconomic status, poor mental health, prior violence, and alcohol and drug abuse. Given that these factors are all risk factors for TBI, drug use, and delinquency, failure to adequately control for these factors may lead to a biased understanding of the role TBI plays in behaviors that led each youth to become incarcerated. The current study aims to systematically account for these factors through propensity score matching with two large samples of incarcerated youth to compare youth with TBI and without TBI on their drug use and delinquent behaviors in the 12 months prior to their incarceration.

Method: Participants (N=901) were drawn from two different datasets of incarcerated youth in Missouri and Pennsylvania. The Missouri study interviewed all incarcerated youth in that state during a three-month period in 2004. The Pennsylvania study used a non-probability sample drawn from one male and one female residential facility between 2009 and 2010. The combined sample was 79.69% male, average age of 15.65, 52.16% were youth of color, and 19.2% reported a lifetime moderate-to-severe TBI. Propensity scores with caliper matching and without replacement identified a matched sample of youth with TBI and youth without TBI using gender, age, race, education level, public assistance receipt, lifetime drug use, lifetime alcohol use, ADHD diagnosis, depression diagnosis, age at first police contact, and age at first referral to juvenile court. The optimal caliper of .08 was determined following the guidelines by Austin (2011). The matched sample was then used to examine bivariate comparisons on 11 different drugs and 13 delinquent behaviors in the 12 months prior to the youth’s incarceration.

Results: Youth with TBI reported higher levels of all drugs assessed for; however, only the use of ecstasy (d = .35, p < .05) and PCP (d = .32, p < .05) were found to be significantly different between groups. Across the different delinquent behaviors, youth with TBI reported consistently higher levels of all 13 delinquent behaviors. Significant differences in behavior were indicated in carrying a hidden weapon (d = .29, p < .05) and being in a gang fight (d = .38, p < .01).

Conclusions and Implications: Results suggest that youth with TBI are likely to present with elevated rates of drug use and delinquent behavior relative to similar youth without TBI. The higher use of ecstasy and PCP among incarcerated youth with TBI was an unexpected finding. Further work is needed to confirm these results and examine why these particular drugs may be used more frequently by youth with TBI. In terms of delinquent behavior, the relationship between TBI and gang activity is consistent with prior research showing gangs are important vectors of violence and victimization, particularly TBI, within justice-involved populations.