Facts & Figures

The generally quoted incidence of ADHD among adults in the U.S. is about 4.4%. 1

Research by Robert Eme and Patrick Hurley has suggested the very conservative incidence of ADHD in the adult offender population to be 25%. This study found that incidences of ADHD in correctional facilities ranged from 22% to over 50%. 2

Russ Barkley’s study of U.S. youth, matched for socioeconomic status and followed for 10 years, found that:

      • 20% of the control group was arrested compared to 48% of the AD/HD group.
      • The control group arrested on average 2.1 times, compared to 6.4 times for the AD/HD group. 3

Studies have found that inmates with mental illness stay in the system over 5X longer than those without. 4

Studies have found that New York’s Riker’s Island, Chicago’s Cook County Jail and the Los Angeles County Jail are the largest mental health institutions in the nation. 5

Adults with ADHD engage in more high-risk behavrios and have a higher rate of substance abuse, more injuries, and more car accidents than non-ADHD adults. 6

65-70% of ADHD cases coexist with another condition or learning disability. 7

Individuals with ADHD have a 50% greater incidence of substance abuse. In cases where ADHD coexists with Conduct Disorder (CD), this number triples. 8

ADHD is highly inheritable. There is a 75% chance a person with ADHD inherited those genes from at least one of his or her parents. 9

50-67% of children with ADHD retain symptoms into adulthood. 10

Adults with ADHD are less likely to be employed- 24% employment for ADHD adults, 79% employment for adults without ADHD. Employment rate improves with medication treatment. 11

 Adults with ADHD have a significantly lower socioeconomic status, a lower level of academic achievement, and higher medical costs than their peers. 12


  1. Kessler et al.,”Lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the National Comorbidity Survey Replication,” Arch Gen Psychiatry, 2005 Jun;62(6):593-602
  2. Robert Eme, PhD and Patrick Hurley, Spinning Out of Control, 2009 (2nd Edition)
  3. Russell A. Barkley, PhD et al. ADHD in Adults, What Science Says. 2008 (4th Edition) Guilford Press p. 205
  4. Fox Butterfield, “Prisons Replace Hospitals for the Nation’s Mentally Ill,” New York Times, March 5, 1998.
  5. E. Fuller Torrey, “Reinventing Mental Health Care,” City Journal 9:4, Autumn 1999.
  6. Breyer et al. 2009; Sabuncuoglu 2007, Wilens and Upadhyaya 2007
  7. Margaret Austen et al., “ADHD Comorbidity,” MentalHelp.net, Nov. 5th 2007, Jan. 18 2013, <http://www.mentalhelp.net/poc/view_doc.php?type=doc&id=13851>
  8. Caroline Helwick, “Combination of Conduct Disorder and ADHD Predictive of Substance Abuse,” Medscape, Jun. 1 2010, Jan. 18, 2013, <http://www.medscape.com/viewarticle/722740>
  9. M.G.H. Rietveld et al, “Heritability of attention problems in children: longitudinal results from a study of twins, age 3 to 12,”  Journal of Child Psychology and Psychiatry, March 2004, Volume 45, Issue 3, pages 577–588
  10. Wilens 2004; Barkley et a. 2002
  11. Halmey et al. 2009
  12. Kleinman et al. 2009; Bernfort et al. 2008