Five common myths and misconceptions about ADHD

In this post Dr Mark Kennedy, a Senior Teaching Fellow at the Institute of Psychiatry, Psychology and Neuroscience, King’s College London, discusses common myths and misconceptions about attention deficit hyperactivity disorder (ADHD).

“Everyone has ADHD nowadays, don’t they?”

When you talk with the general public about ADHD, one of the first things people mention is how common it is ‘nowadays’ and cite figures like 20% of all boys in the USA being diagnosed with ADHD. In the UK, things are quite different. ADHD diagnosis rates are around 1% (Sayal et al., 2018). From population-based studies, we know that around 5% of children have ADHD (Polancyk et al., 2014). So, this means ADHD is actually underdiagnosed in the UK.

Why is that a problem, you may ask? There’s a lot of research which looks at outcomes in adulthood for those with ADHD, and crucially whether they’ve ever been diagnosed or not. These studies provide clear evidence that, for some, the outcomes aren’t good. ADHD has been found to predict poorer educational and employment outcomes and, sadly, early mortality (accidents being a leading cause) (e.g., Barbaresi et al., 2013). The evidence also suggests that careful management can help to avert these poorer outcomes, particularly in the school years (e.g., Uchida et al., 2018).

Going back to the “nowadays” bit. There seems to be an assumption that ADHD rates have increased in recent years due to factors like too many fizzy drinks and too much time using iPads. Tracking ADHD rates is a complicated task, as diagnostic criteria have evolved over time. But the evidence we have suggests that the rate of 5% has actually been really stable over time, at least since the 1980s (Polanczyk et al., 2014).

Medication is recommended as the first course of action

It’s true that medication, usually stimulants, are the most common treatment for ADHD. But importantly, the National Institute for Health and Care Excellence (NICE) suggests that environmental modifications should be attempted before considering medication. This is because in some cases, medication might not be necessary. There may be things parents and teachers can do to help children function without the need for medication – and the course Understanding ADHD: Current Research and Practice discusses some of these.

Hyperactivity is the most common presentation of ADHD

When you ask people what ADHD is, they describe a child with too much energy. In reality, there’s a lot more to ADHD than hyperactivity. In fact, there are three presentations of ADHD: hyperactive-impulsive, inattentive and combined type. The most common form in the general population is inattentive, not hyperactive-impulsive (e.g., Froehlich et al., 2007), which comes as a surprise to some people.

ADHD only affects boys

One of the main stereotypes of ADHD is a boy running around a classroom. In clinics, boys are more often referred for help (at a rate of around 4:1), but when we look at the general population, we see that the ratio of boys to girls with ADHD is actually much more narrow (around 2 boys for every 1 girl) (e.g., Ramtekkar et al., 2010). The reasons for this are complicated, but at a minimum, it means that ADHD seems to be missed in girls.

One of the parents we speak to in our course provides a really good illustration of this when she discusses her daughter (who now has a diagnosis of ADHD) in school. Her daughter’s report cards would say things like “struggles to keep on task” and “easily distracted”, but the teachers hadn’t considered that she might have ADHD.

ADHD only affects children

This is an interesting one. It’s true that early studies focused on children with ADHD and there was often an assumption that children would ‘grow out of it’. But more recently, researchers have begun to follow up children with ADHD as they become adults. Exact figures vary, but somewhere around 30-40% of children with ADHD in childhood will continue to meet full criteria by adulthood (e.g., Caye et al., 2016).

So does that mean that the rest ‘grow out of it’? Not exactly. The evidence suggests that persistence is strongest amongst those who have more severe ADHD and that a number will not meet the full criteria of ADHD. Nevertheless, these people will still be somewhat impaired by the symptoms they do have.

Learn more about ADHD, including symptoms, treatment and the latest research on the course Understanding ADHD: Current Research and Practice.


Barbaresi, W. J., Colligan, R. C., Weaver, A. L., Voigt, R. G., Killian, J. M., & Katusic, S. K. (2013). Mortality, ADHD, and psychosocial adversity in adults with childhood ADHD: a prospective study. Pediatrics, 131(4), 637.

Caye, A., Spadini, A. V., Karam, R. G., Grevet, E. H., Rovaris, D. L., Bau, C. H., … & Kieling, C. (2016). Predictors of persistence of ADHD into adulthood: a systematic review of the literature and meta-analysis. European child & adolescent psychiatry, 25(11), 1151-1159.

Froehlich, T. E., Lanphear, B. P., Epstein, J. N., Barbaresi, W. J., Katusic, S. K., & Kahn, R. S. (2007). Prevalence, recognition, and treatment of attention-deficit/hyperactivity disorder in a national sample of US children. Archives of pediatrics & adolescent medicine, 161(9), 857-864.

Polanczyk, G. V., Willcutt, E. G., Salum, G. A., Kieling, C., & Rohde, L. A. (2014). ADHD prevalence estimates across three decades: an updated systematic review and meta-regression analysis. International journal of epidemiology, 43(2), 434-442.

Ramtekkar, U. P., Reiersen, A. M., Todorov, A. A., & Todd, R. D. (2010). Sex and age differences in attention-deficit/hyperactivity disorder symptoms and diagnoses: implications for DSM-V and ICD-11. Journal of the American Academy of Child & Adolescent Psychiatry, 49(3), 217-228.

Sayal, K., Prasad, V., Daley, D., Ford, T., & Coghill, D. (2018). ADHD in children and young people: prevalence, care pathways, and service provision. The Lancet Psychiatry, 5(2), 175-186.

Uchida, M., Spencer, T. J., Faraone, S. V., & Biederman, J. (2018). Adult outcome of ADHD: an overview of results from the MGH longitudinal family studies of pediatrically and psychiatrically referred youth with and without ADHD of both sexes. Journal of attention disorders, 22(6), 523-534.

Category Learning, Healthcare

Comments (15)


  • Basharat Waheed

    Very informative, I am joining the course starting on 24 June .Really looking forward fot the course

  • Abdi

    I like to follow this course but I couldn’t managed to
    access the next lesson.

  • Myriam

    I once had a student with ADHD in primary school (4th form) and he was really hyperactive. He was medicated and, as he attended lessons with me in the afternoon, the mother always told me if she had to increase the dose, I had to let her know. Obviously, in the afternoon the effect of the drug was not that powerful as in the morning but I said nothing and tried to resort to other strategies for the child not to be more medicated!!!

  • Victoria

    As step-parent to a child with FASD I think that part of the problem with some ADHD diagnosis is that symptoms of various disorders can have ADHD- like symptoms and this as a diagnosis is not necessarily useful for treating the overall problem for patients in these instances.

  • ahmed mohamed

    thank you doctor for you valued article ,
    my son had affected by birth injury ,result in damage in some cells of brain as shown by MRI , he is now 8 years old but unlikely he suffer from
    – ADHD ,
    -delayed speech , cannot speak till now
    -convulsions , 1 minor focal episodes every 6 months
    – minor abnormality in walk movement
    -my wife suffer a lot from his attitude and behavior , to the extent that she cannot handle him because he become more stronger than her.
    he is treated by tegretol syp. for convulsion , physiotherapy for his minor impaired movement, speech lessons but unlikely still has no results
    the good signs we had ,
    his IQ is improved over the time , although he cannot speak but he understand and sometime respond to all my oral commands and do what we asked him to do.
    my question , is there any thing could we do to help him speak ?

  • Eshraga Osama

    Thank you Dr Mark to be with us
    addition to your take, i thing tge family has affect in this (e.x if the family allways has problem the children wil be nervous cant sit in one place)another reson the parent if they hit the lm the children will be lack of concentration and move from place to another because they afraid.
    all of us know at recent days the chldren eat sweet more and the suger let person move more.
    I agree with you about the ipad and another gams like playstation 4 they do what see and that will let them all day move to do diffrent move, this will affect negetive on their mind concentration all their mind how can success in the gams.
    the end ihope the parents shoud oblige their children to play the mlgames that active memory, games that neet to focus to solve it, also agree with you to agood and carefilly managment.
    Thanks for your attention

  • Anna

    Whatever in this article is really good. But I have came with a point of suggestion that the best choice of treatment is environmental modification than the medications. Why because its(ADHD) exact cause is unknown so we can’t predict the effect of stimulants easily.

  • Jennifer Randall

    It was interesting to read the article. My youngest son was diagnosed with it at the age of ten. He is the hyperactive impulsive. We went through environmental changes and dietary changes as well but it was deemed necessary for him to be put on dexanphetamins which only make him cry for a whole month. He was then changed to Ritaline which made a difference to his concentration and helped with school. He was getting in trouble a lot by that time. He never liked being on the medication he said it made him self like he wasn’t himself.

  • Mohammed

    Hopefully,someone mention about which types of stimulants will be function to ADHD suferers.

  • Tamara

    It´s very interesting the article, and I am also curious about the origin of ADHD, and the scientific reason that is more in children than in girls…
    thank you!

  • Latifa

    Hello I carefully read this useful logs thanks for this wonderful information .One thing that I want to know is what is ADHD come from?

  • Professor David Clark

    ‘When you talk with the general public about ADHD, one of the first things people mention is how common it is “nowadays” and cite figures like 20% of all boys in the USA being diagnosed with ADHD. In the UK, things are quite different. ADHD diagnosis rates are around 1% (Sayal et al., 2018). From population-based studies, we know that around 5% of children have ADHD (Polancyk et al., 2014). So, this means ADHD is actually under diagnosed in the UK.’
    Where is evidence that ADHD is under-diagnosed in UK? In fact, evidence indicates that ADHD is over-diagnosed in USA. Please provide evidence that ADHD as a syndrome even exists.
    There is no evidence that ritalin – an amphetamine drug that is illegal unless prescribed by a doctor, and has adverse affects on young children – works with so-called ADHD.
    Just because a child struggles with a school course does not mean (s)he has ADHD.
    I am saddened by what you offer here. Please leave my comment here so reader can see an alternative view.
    I hate your term ‘these people’… they are children. And they don’t need labelling.
    I say this as someone who has worked in mental health 40 years, 25 years in brain science & amphetamine.

    • Nan Smit

      My non-verbal Autistic grandson was diagnosed with ADHD at age 6. He was commenced on Ritalin, and within a week he became a settled, happy little man, with words tumbling out as his little brain had “slowed down” and given him the time to think of what to say. The results were sudden and dramatic. And Ritalin does not work???!

    • Rheese

      Be very careful,,because it seems that the medical profession is labeling everything.As a child I had a hearing impairment and in those days if you deaf you were dumb.And I started to believe it.But this is not the case. So be very very careful.if are told something don’t always believe it.Even if you justify it with scientific research.Good luck. Rheese Rodgers.

    • Martin Krauser

      The evidence is provided by over a century of behavioral diagnoses. Since you are not alone in not giving these much credence, there have also been extensive brain imaging studies connected to ADHD. The course that this blog post is a part of is in its first week and has so far provided a brief description of the neurology, with a list of references. I have provided this list in an abridged form due to the size limit of comments here.

      You are, of course, entitled to an alternative view, but the fact that a layperson is able to provide this evidence to you, a long-standing professional, is indicative that you don’t care much to find it.

      doi:0707741104 [pii] 10.1073/pnas.0707741104
      Rubia, K. (2018b). ‘Brain function in ADHD’. In T. Banaschewski, Coghill, D. Zuddas, A. (Ed.), Oxford Handbook for ADHD.
      Arnsten, A., & Rubia, K. (2012). ‘Neurobiological Circuits Regulating Attention, Movement and Emotion and Their Disruptions in Pediatric Neuropsychiatric Disorders’. Journal of the American Academy of Child and Adolescent Psychiatry, 51(4)