What causes ADHD?
Although DSM5 acknowledges its aetiology (causes) are uncertain, it classifies ADHD as a neurodevelopmental disorder, implying it is associated with brain dysfunction.[1] Despite this uncertainty many ADHD proponents promote the clinically dominant (but unproven and increasingly discredited) working hypothesis is that ADHD is caused by genetically predetermined malfunctions in dopamine pathways in the brain.[2]
They contend that the “therapeutic effect of stimulants is achieved by slow and steady increases of dopamine” which replicate the way 'normal brains' reward on task behaviours.[3] Despite decades of research seeking to prove it, the 'dopamine hypothesis' is less credible than it was when it was originally proposed.[4] Paradoxically there is evidence that long term exposure to 'therapeutic' stimulants (i.e. amphetamines), may cause dopamine system malfunction, raising concerns that the extended use of stimulant medication may cause, rather than cure or manage, ADHD.[5] Nonetheless, global prescribing rates for stimulants to treat ADHD are increasing.
Some ADHD proponents, again without robust supporting evidence, have broadened the dopamine hypothesis. They now hypothesize that rather than being a single condition related to dopamine, ADHD is a heterogeneous condition with multiple neuropsychological pathways causing different subtypes of the disorder.[6]
The many and varied causes of ADHD type behaviours - Many non-biological factors have been associated with an increased risk of being diagnosed with, or treated for ADHD. They include being younger than your classmates[7], divorce and family dysfunction[8], poverty[9], low maternal education, lone parenthood and the reception of social welfare[10], sexual abuse[11], sleep deprivation[12], perinatal issues[13], artificial food additives[14] mobile phone use with high lead exposure[15] and, of course, being a boy approximately triples a child's chances of being diagnosed and medicated.[16]
Critics assert the diagnostic process results in a host of socio-environmental factors contributing to behaviours being pathologised as a disease.[17] They argue that many of the 18 diagnostic criteria (fidgeting, blurting out answers, not seeming to listen, disliking schoolwork or homework etc.) are normal behaviours particularly for boys, “not designed by evolution to sit around at a desk for hours at a time paying attention to a teacher”.[18] Proponents counter by acknowledging many people without ADHD are occasionally impulsive and/or hyperactive, but argue that what distinguishes ADHD sufferers from the rest of the population is their level of behavioural impairment or dysfunction.
Is non-compliance at the core of an ADHD diagnosis? - In addition to inattention and/or impulsivity/hyperactivity some proponents regard non-compliance as a core problem of ADHD.[19] In contrast critics are concerned by the potential for psychostimulants to reduce a child’s interest in social interactions and exhibit unnatural compliance known as the ‘zombie effect’.[20] DSM5 states “Social deviant behaviour (e.g. political, religious, or sexual) and conflicts that are primarily between the individual and society are not mental disorders”.[21] Many of the diagnostic criteria (e.g. playing too loudly, interrupting, not waiting turn, leaving seat when expected to remain seated) are non-compliant and arguably ‘social deviant’ behavior. Critics contend that by medicalising social deviant behaviours the DSM5 fails to meet its own criteria for a valid psychiatric disorder.[22]
Critics also argue that along with essentially well children at the “tail of the bell curve” of normal hyperactive/inattentive behaviours[23], there is a second subset of misdiagnosed children and adolescents who have a very diverse range of causes for their problematic behaviour. They argue that for these children ADHD is an unhelpful label in that it promotes the inaccurate and dangerous assumption that there is common cause and treatment and inhibits the identification and appropriate response to their individual circumstances.[24]
References
[1] American Psychiatric Association (2013), Diagnostic and Statistical Manual of Mental Disorders. Fifth Edition, (DSM-5) p. 31
[2] Levy F. The dopamine theory of attention deficit hyperactivity disorder (ADHD). Aust N Z J Psychiatry. 1991 Jun;25(2):277-83 https://www.ncbi.nlm.nih.gov/pubmed/1652243
[3] U.S. National institute of drug abuse, Stimulant ADHD Medications: Methylphenidate and Amphetamines (January 2014) https://www.drugabuse.gov/sites/default/files/drugfacts_stimulantadhd_1.pdf
[4] Gonon F. The dopaminergic hypothesis of attention-deficit/hyperactivity disorder needs re-examining. Trends Neurosci. 2009 Jan;32(1):2-8. doi: 10.1016/j.tins.2008.09.010. Epub 2008 Nov 3.
https://www.ncbi.nlm.nih.gov/pubmed/18986716
[5] Gene-Jack Wang,1,2,3,* Nora D. Volkow,4,5 Timothy Wigal,6 Scott H. Kollins,7 Jeffrey H. Newcorn,3 Frank Telang,5 Jean Logan,2 Millard Jayne,5 Christopher T. Wong,5 Hao Han,8 Joanna S. Fowler,2,3 Wei Zhu,8 and James M. Swanson6 Long-Term Stimulant Treatment Affects Brain Dopamine Transporter Level in Patients with Attention Deficit Hyperactive Disorder. Published online 2013 May 15. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3655054/
[6] Wåhlstedt C1, Thorell LB, Bohlin G. Heterogeneity in ADHD: neuropsychological pathways, comorbidity and symptom domains. J Abnorm Child Psychol. 2009 May;37(4):551-64. doi: 10.1007/s10802-008-9286-9. https://link.springer.com/article/10.1007/s10802-008-9286-9
[7] Whitely M, Raven M, Timimi S, Jureidini J, Phillimore J, Leo J, Moncrieff J, Landman P, Attention deficit hyperactivity disorder late birthdate effect common in both high and low prescribing international jurisdictions: systematic review, Journal of Child Psychology and Psychiatry, October 2018. https://onlinelibrary.wiley.com/doi/abs/10.1111/jcpp.12991
[8] Allen, D. M. (2010). How dysfunctional families spur mental disorders: A balanced approach to resolve problems and reconcile relationships. Santa Barbara, CA: Praeger. Interview with the author available at https://www.youtube.com/watch?v=daGg-gwO2s4
[9] Russell, G., Ford, T., Rosenberg, R., & Kelly, S. (2013). The association of attention deficit hyperactivity disorder with socioeconomic disadvantage: Alternative explanations and evidence. Journal of Child Psychology and Psychiatry, 55(5), 436–445.
https://www.ncbi.nlm.nih.gov/pubmed/24274762
[10] Hjern, A., Weitoft, G. R., & Lindblad, F. (2010) Social adversity predicts ADHD-medication in school children–a national cohort study. Acta Paediatrica (Oslo, Norway: 1992), 99(6), 920–924. https://onlinelibrary.wiley.com/doi/full/10.1111/j.1651-2227.2009.01638.x
[11] Weinstein, D., Staffelbach, D., & Biaggio, M. (2000). Attention-deficit hyperactivity disorder and posttraumatic stress disorder: Differential diagnosis in childhood sexual abuse. Clinical Psychology Review, 20(3), 359–378. https://www.sciencedirect.com/science/article/pii/S027273589800107X
[12] Thakkar, V. G. (2013, April 28). Diagnosing the wrong deficit. The New York Times, pp. SR1. https://www.nytimes.com/2013/04/28/opinion/sunday/diagnosing-the-wrong-deficit.html
[13] Schmitt, J., & Romanos, M. (2012). Prenatal and perinatal risk factors for attention-deficit/hyperactivity disorder. Archives of Pediatrics & Adolescent Medicine, 166(11), 1074–1075. https://jamanetwork.com/journals/jamapediatrics/fullarticle/1357759
[14] McCann, D., Barrett, A., Cooper, A., Crumpler, D., Dalen, L., Grimshaw, K, Stevenson, J. (2007). Food additives and hyperactive behaviour in 3-year-old and 8/9-year-old children in the community: A randomised, double-blinded, placebo-controlled trial. Lancet, 370(9598), 1560–1567. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(07)61306-3/fulltext
[15] Byun, Y., Ha, M., Kwon, H., Hong, Y., Leem, J., Sakong, J., … Scott, J. G. (2013). Mobile phone use, blood lead levels, and attention deficit hyperactivity symptoms in children: A longitudinal study. Plos One, 8(3), e59742. https://www.ncbi.nlm.nih.gov/pubmed/23555766
[16] Salynn Boyles, ‘Study confirms ADHD is more common in boys’, WebMD Health News, 15 September 2004. Available at http://www.webmd.com/add-adhd/news/20040915/study-confirms-adhd-is-more-common-in-boys (accessed 4 October 2009).
[17] This article openly challenges the scientific validity and reliability of current ADHD assessment tools and questions the ethics involved in prescribing dangerous and addictive drugs to children. In addition, particular attention will be given to familial, political, economical, biological, ethological, historical, and evolutionary correlates as they relate to the myth of ADHD in America. The goal of this article is to offer a theoretically sound alternative to the current medical model and to challenge the existing ADHD paradigm that pathologizes historically documented, normal-range child behavioral patterns. Stolzer, J. M. (2007). The ADHD epidemic in America. Ethical Human Psychology and Psychiatry: an International Journal of Critical Inquiry, 9(2), 109–116. doi:10.1891/152315007782021204 http://www.ingentaconnect.com/content/springer/ehpp/2007/00000009/00000002/art00005
[18] Francis Fukuyama, Professor of International Political Economy at John Hopkins University, cited in Baughman and Hovey, The ADHD Fraud, p.17.
[19] Prominent ADHD proponent American psychologist Dr R Barkley was quoted as saying: "Although inattention, overactivity, and poor impulse control are the most common symptoms cited by others as primary in hyperactive children, my own work with these children suggests that non-compliance is also a primary problem". Quoted in Fred A. Baughman Jr., MD and Craig Hovey, The ADHD Fraud: How Psychiatry Makes ‘Patients’ of Normal Children, Trafford Publishing, Victoria BC, 2006, pp. p. 33.
[20] Peter R. Breggin, M.D., Talking Back to Ritalin: What Doctors Aren’t Telling You about Stimulants for Children, Common Courage Press, Monroe, 1998 pp. 58–60.
[21] American Psychiatric Association (2013), Diagnostic and Statistical Manual of Mental Disorders. Fifth Edition, (DSM-5) p20
[22] Freeman, J. E. & Honkasilta, J. M. (2017). Dictating the boundaries of ab/normality: A critical discourse analysis of the diagnostic criteria for attention deficit hyperactivity disorder and hyperkinetic disorder. Disability & Society, 32 (4), 565–588. http://www.tandfonline.com/doi/abs/10.1080/09687599.2017.1296819
[23] Francis Fukuyama, Professor of International Political Economy at John Hopkins University, cited in Baughman and Hovey, The ADHD Fraud, p.17.
[24] “There is always a more compelling and more treatable explanation than dumbing down the understanding by calling it ADHD.” Professor Jon Jureidini, professor of psychiatry at the University of Adelaide , told MJA InSight https://www.doctorportal.com.au/mjainsight/2013/43/adhd-critique-divides-specialists/