A comprehensive typology of substance misusing offenders :: towards an understanding of offender diversity
University of New Brunswick
The rates of substance use disorders (SUDs) are higher in offenders than in the general population. The Substance Use Risk Profile (SURP) model posits that there are four personality vulnerability subtypes associated with distinct patterns of substance misuse and comorbid psychopathology, including: impulsivity, sensation seeking, anxiety sensitivity, and introversion/hopelessness. Interventions matched to these personality vulnerability subtypes have been found to be effective for reducing substance use behaviours and symptoms of comorbid psychopathology. However, this model, which was developed with female substance misusers and replicated only in high school students, lacks validation in an offender population. Therefore, the first goal of this dissertation was to validate the SURP personality model in male offenders. Furthermore, this dissertation assessed whether the SURP model could postdict self-reported institutional substance use (i.e., illicit substance use or misuse of prescription medication while incarcerated). Finally, this dissertation advanced the theoretical understanding of the relationship between SUDs and criminal behaviour by examining the link between the SURP personality variables and behavioural indicators of both substance misuse and antisocial personality disorder. The SURP model did not replicate as expected, as offenders were clustered based on varying degrees of the severity of their substance use, mental health comorbidity, and global elevations in personality vulnerabilities. Specifically, the latent class cluster analysis revealed the presence of three distinct clusters, characterized by low, moderate, and high elevations in personality traits and substance misuse. Survival analysis revealed a trend for cluster membership to predict survival time before engaging in institutional substance misuse. Specifically, high levels of sensation seeking and a trend towards low levels of anxiety sensitivity postdicted shorter times to engaging in institutional substance use. Finally, canonical correlations revealed that high impulsivity, introversion/hopelessness, and sensation seeking were linked to higher levels of antisociality, drug and alcohol dependence, self-rated substance use severity, criminal versatility, and younger ages of first use and first arrest. Moreover, low AS was linked to increased criminal versatility and a reduced frequency of drug arrests. These findings emphasize the role that certain personality characteristics play in substance use and criminal behaviour and the need to target these in correctional programs.