Attention Deficit
Hyperactivity Disorder
Studies indicate that both children and adults can suffer from ADHD. And while the cause of ADHD is still unknown, researchers believe genetics, diet, environmental factors, and even infections and an abnormal immune system play a role.

Attention Deficit/Hyperactivity Disorder
Attention deficit/hyperactivity disorder (ADHD) is typically viewed as a behavioral disorder that impacts only children. To be diagnosed with ADHD, symptoms must have started before age 12. However, new research suggests that adults can also develop ADHD or symptoms which mimic the disorder.
Late-onset ADHD has long been perceived as merely a continuation of ADHD that went undiagnosed in childhood. But several studies now dispute that view, claiming adults can develop ADHD behaviors and that these patients may have a separate and distinct syndrome. 3

Can adolescents or adults develop symptoms of ADHD?

Several studies indicate that adolescents and adults can, in fact, develop symptoms of ADHD and that it may not be the result of an undiagnosed childhood disorder. One study found that 85% of people with ADHD did not have the disorder as a child. “The findings of this study do not support the assumption that adulthood ADHD is necessarily a continuation of childhood ADHD.” 1

Another study found, 90% of adult ADHD cases did not have a history of childhood ADHD. 2 Therefore, ADHD symptoms can develop in adults “and may be a syndrome distinct from childhood-onset ADHD.” 3

A variety of factors can impact whether an adolescent or adult develop ADHD. These can include genetics, environmental influences, and dietary habits. Even exposure to infections coupled with an immune dysfunction can cause ADHD-like symptoms in some individuals.

Abnormal immune system response triggering symptoms that mimic ADHD

Common infections, which often times may be hidden and go undiagnosed, can induce an abnormal immune system response. Antibodies produced to attack the harmful bacteria or virus, instead, may attack healthy cells in the brain.

An autoimmune attack on the brain can cause inflammation in a specific region of the brain (basal ganglia), triggering symptoms that mimic ADHD. Patients with an infection-triggered autoimmune encephalopathy may often be misdiagnosed with a psychiatric illness or behavioral disorder (such as ADHD), when instead they may have a treatable autoimmune disorder.

Strep infections, for example, have been linked to a subgroup of patients with ADHD. 4 And researchers have found that “streptococcal infections and autoimmune reactions against the basal ganglia are more frequent in ADHD patients.” 5

Enteroviruses have also been associated with ADHD-like symptoms. Studies have shown that some patients with this virus experienced “increased symptoms of inattention, hyperactivity, oppositional defiance, internalizing problems, and increased likelihood of ADHD diagnosis.” 6

And researchers believe cytomegalovirus (HCMV), a common herpes virus, has the “potency to be responsible for at least part of ADHD cases.” 7 This virus has been shown to be associated with schizophrenia, bipolar disorder and cognitive deficits in certain populations. 8

Other infections linked to symptoms of ADHD

Other infections linked to symptoms of ADHD include: Candida albicans (a common yeast infection); allergic diseases (i.e. atopic eczema, chronic sinusitis, allergic rhinitis) 9; varicella-zoster virus (VZV), which causes chickenpox; herpes zoster (the shingles virus); middle ear infections 10 and allergic conjunctivitis. 11 An infection with Borrelia burgdorferi, the bacteria causing Lyme disease, can result in symptoms that mimic ADHD. 12

  1. Caye A, Rocha TB, Anselmi L, et al. Attention-Deficit/Hyperactivity Disorder Trajectories From Childhood to Young Adulthood: Evidence From a Birth Cohort Supporting a Late-Onset Syndrome. JAMA Psychiatry. 2016;73(7):705–712.
  2. Moffitt TE, Houts R, Asherson P, et al. Is Adult ADHD a Childhood-Onset Neurodevelopmental Disorder? Evidence From a Four-Decade Longitudinal Cohort Study. Am J Psychiatry. 2015;172(10):967–977.
  3. Agnew-Blais JC, Polanczyk GV, Danese A, Wertz J, Moffitt TE, Arseneault L. Evaluation of the Persistence, Remission, and Emergence of Attention-Deficit/Hyperactivity Disorder in Young Adulthood. JAMA Psychiatry. 2016;73(7):713–720.
  4. WebMD. Strep infections may be associated with ADHD. May 12, 2000.
  5. Toto, M., Margari, F., Simone, M., Craig, F., Petruzzelli, M. G., Tafuri, S., & Margari, L. (2015). Antibasal Ganglia Antibodies and Antistreptolysin O in Noncomorbid ADHD. Journal of Attention Disorders, 19(11), 965–970.
  6. Susan Shur-Fen Gau, Luan-Yin Chang, Li-Min Huang, Tsui-Yen Fan, Yu-Yu Wu, Tzou-Yien Lin. Attention-Deficit/Hyperactivity–Related Symptoms Among Children With Enterovirus 71 Infection of the Central Nervous System. Pediatrics Aug 2008, 122 (2) e452-e458.
  7. Zhou R, Xia Q, Shen H, Yang X, Zhang Y, Xu J. Diagnosis of children's attention deficit hyperactivity disorder (ADHD) and its association with cytomegalovirus infection with ADHD: a historical review. Int J Clin Exp Med. 2015;8(8):13969–13975. Published 2015 Aug 15.
  8. Assinger A, Yaiw KC, Göttesdorfer I, Leib-Mösch C, Söderberg-Nauclér C. Human cytomegalovirus (HCMV) induces human endogenous retrovirus (HERV) transcription. Retrovirology. 2013;10:132. Published 2013 Nov 12.
  9. Romanos M, Gerlach M, Warnke A, et al. Association of attention-deficit/hyperactivity disorder and atopic eczema modified by sleep disturbance in a large population-based sample. Journal of Epidemiology & Community Health 2010;64:269-273.
  10. Andrew R. Adesman, Lisa A. Altshuler, Paul H. Lipkin, Gary A. Walco. Otitis Media in Children With Learning Disabilities and in Children With Attention Deficit Disorder With Hyperactivity. Pediatrics Mar 1990, 85 (3) 442-446.
  11. Jeng-Dau Tsai, Shih-Ni Chang, Chih-Hsin Mou, Fung-Chang Sung, Ko-Huang Lue. Association between atopic diseases and attention-deficit/hyperactivity disorder in childhood: a population-based case-control study. Annals of Epidemiology. Volume 23, Issue 4, 2013, Pages 185-188.
  12. Brian A. Fallon, Janice M. Kochevar, Andrea Gaito, Jenifer A. Nields. The underdiagnosis of neuropsychiatric Lyme disease in children and adults. Psychiatric Clinics of North America, Volume 21, Issue 3, 1998, Pages 693-703.
Herpes virus HCMV can be responsible for adult ADHD

The herpes virus HCMV has the “potency to be responsible for at least part of ADHD cases.” 7

Infections may cause ADHD that develops in adults and children
How can an infection cause ADHD symptoms?

Learn more about how infections can trigger neuropsychiatric symptoms

Cunningham Panel helps identify an autoimmune disorder in child initially diagnosed with schizophrenia

Cunningham Panel™ helps identify an autoimmune disorder in child initially diagnosed with schizophrenia

Researchers describe a complex case involving a 15-year-old girl, who abruptly developed multiple neurologic and psychiatric symptoms.

Autoimmune diseases and severe infections as risk factors for mood disorders: a nationwide study

Autoimmune diseases and severe infections as risk factors for mood disorders: a nationwide study

This nationwide, population-based, prospective cohort study examines the link between mood disorders, infections, and autoimmune disease.

Childhood infections can increase risk of mental illness in kids

Childhood infections can increase risk of mental illness in kids

Nationwide study finds both mild and severe infections can increase risk of mental disorders in children and adolescents.

  • Test Order Process
    The Cunningham Panel™ – Antibody testing that helps determine whether an autoimmune response may be triggering neurologic and/or psychiatric symptoms.