Previous research has shown that a significant percentage of offenders are affected by adult attention deficit hyperactivity disorder (ADHD) and its related symptoms, however it is unknown the extent to which this disorder affects federal inmates in Canada and the impact ADHD has on key correctional outcomes. Four hundred and ninety-seven male federal offenders were assessed at intake over a fourteen month period using the Adult ADHD Self-Report Scale (ASRS). Approximately 16.5% scored in the highest range, which is consistent with the clinical threshold for diagnosis for the disorder; a further 25.2% reported sub-threshold symptoms in the moderate range. ADHD symptoms were found to be associated with unstable job history, presence of a learning disability, lower educational attainment, substance abuse, higher criminal risk and need levels, and other mental health problems. ADHD symptoms were also found to predict institutional misconduct. Additionally, offenders with high levels of ADHD symptomatology fared more poorly on release to the community. Implications for institutional behavior management and the need for additional resources and adapted interventions are discussed.
Attention deficit hyperactivity disorder (ADHD) is a neurobiological disorder characterized by difficulties in regulating attention, activity, and impulsivity (APA, 2000). The literature has isolated three types of ADHD: the predominately inattentive type, the predominantly hyperactive–impulsive type, and the combined type. While high levels of ADHD symptoms are required to reach the threshold for a clinical diagnosis, recent research has shown that problems associated with ADHD are evident with lower levels of symptomology as well. This research suggests that the disorder actually exists on a continuum, with severe symptoms at the upper end of the spectrum (Levy et al., 1997 and Lubke et al., 2009).
Although more commonly diagnosed in childhood and adolescence, symptoms persist into adulthood for many individuals. Recent epidemiological studies estimate the adult prevalence rate of ADHD in the general population to be 2–5% (Faraone et al., 2003, Fayyad et al., 2007, Kessler et al., 2006, Rosler et al., 2004 and Simon et al., 2009), with rates typically being higher for men. While there is a wide range of rates estimated for ADHD in adult forensic populations, most are considerably higher than among non-offender populations, ranging from 4% to 72% in American and European forensic samples (Eme, 2009, Eyestone and Howell, 1994, Ghanizadeh et al., 2011, Rasmussen et al., 2001, Retz et al., 2004, Rosler et al., 2004 and Westmoreland et al., 2010). There is currently no information on the prevalence of ADHD among Canada's federal offender population.
Deficiencies in self-control and self-regulation characterizing adult ADHD have been theoretically and empirically linked to criminal behavior, a likely factor behind the higher than expected prevalence rates in offender populations. Studies have confirmed that low levels of self-control are predictive of a variety of antisocial and criminal behaviors (Gottfredson and Hirschi, 1990, Longshore, 1998, Pratt et al., 2002 and Vazsonyi et al., 2001). Pratt and Cullen (2000) argue that low self-control is consistently one of the strongest correlates of crime regardless of how self-control is measured.
Other explanations for the link between ADHD and criminality focus on the high rates of psychiatric comorbidity between ADHD and other mental health diagnoses typical of forensic populations. Strong associations have been found between ADHD and mood and anxiety disorders (Biederman, 2004 and Kessler et al., 2006), as well as antisocial personality disorder (APD) and psychopathy (Collins and White, 2002, Einarsson et al., 2009, Langevin and Curnoe, 2011, Westmoreland et al., 2010 and Young et al., 2009). Some researchers have gone so far as to claim that severe antisocial personality disorder is directly explained by the neurological symptoms that are features of ADHD (Langevin & Curnoe, 2011). Links between ADHD and substance abuse have also been reported (Biederman et al., 1998, Mannuzza et al., 1998 and Sullivan and Rudnik-Levin, 2001). High rates of substance abuse, antisocial personality disorder, and other psychological disorders are routinely found in forensic populations (Diamond et al., 2001, Fazel and Danesh, 2002, Kunic and Grant, 2006 and Steadman et al., 2009).
Although it has been well-established in the literature that ADHD is prevalent in correctional populations, few studies to date have examined the influence of ADHD on a range of correctional outcomes for adult offenders as well as its implications for institutional management. Offenders with ADHD may have more trouble adjusting to the constraints of incarceration as well as increased difficulty following the rules of the institution and managing relationships with other offenders (Pratt et al., 2002). A recent study of incarcerated male offenders in the UK found that ADHD had a significant effect on the total number of critical incidents as well as the severity of incidents occurring in a Scottish prison (Young et al., 2009).
There is presently a lack of research on the precise relationship between adult ADHD and criminal recidivism. Studies in this area have focused predominantly on young offenders, with results generally supporting the finding that ADHD is a risk factor for recidivism among youths (Putnins, 2005). However, there is some evidence that ADHD in this population is only predictive of recidivism in the presence of conduct disorder (Soderstrom, Sjodin, Carlstedt, & Forsman, 2004). Fewer studies have been conducted with adult offenders; but it is also possible that ADHD increases the risk of reoffending particularly when combined with antisocial personality disorder.
The purpose of the present study is to estimate the prevalence of symptoms consistent with ADHD in a sample of male Canadian federal offenders, to examine the relationship between various levels of ADHD symptomatology and institutional outcomes such as program participation and institutional misconducts, and to investigate the relationship between ADHD symptoms and outcomes on community release from prison.
