Is ADHD the new epidemic?

ADHD is growing in prevalence, increasing demand for services

Dr Aoife O'Sullivan, GP, Clinical Lead for Mental Health, Irish College of General Practitioners

October 6, 2023

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  • Over the past few years GPs have noticed a gradually increasing number of patients presenting with symptoms and concerns about possible adult ADHD. Since 2020 the increase could almost be described as an epidemic. 

    GPs all over Ireland and indeed worldwide have been experiencing the same phenomenon. A perfect storm of rising awareness, social media and Covid lockdowns have triggered an unprecedented demand for ADHD services, diagnosis and treatment.

    ADHD was first described in 19021 (although it was not known by this name until a lot later) and the use of stimulants to treat ADHD was first described in 1937.2  So it’s not a new phenomenon. The diagnosis and treatment of ADHD has been controversial since the 1970s and we are still experiencing the impact of this controversy on both medical and public opinion today. 

    So, what is ADHD?

    Attention deficit hyperactivity disorder is a neurodevelopmental condition which is estimated to affect 5-10% of the population. It is considered to be a neurodivergent condition3 – similar to and having overlaps with ASD (autism spectrum disorder) and dyslexia – the term describes those whose brain differences affect how their brain works. It is a genetic condition with very high (70%) heritability4 characterised by faulty dopamine transmitters and low dopaminergic functioning.

    Molecular genetic studies suggest several genes involved in the regulation of neurotransmitter function interact to produce a disorder of this function associated specifically with dysregulation of dopamine and noradrenaline.5 Under-functioning of these two transmitters results in the clinical symptoms of inattention, hyperactivity and impulsivity. 

    Interestingly, methylphenidate (Ritalin/Concerta), the main medication used to treat ADHD, increases the levels of both these neurotransmitters.6 MRI data published in The Lancet in 2017 shows structural brain differences in patients with ADHD.

    This helps us to understand that ADHD is a real, physiological condition that is in fact probably underdiagnosed in Irish adults. In about 60% of those with childhood ADHD the condition persists into adulthood.7 In addition, it affects approximately 20% of patients attending adult mental health services with other conditions8,9 and between 25-50% of the prison population.10,11

    Studies show that adults with untreated ADHD have fewer social relationships and friends, higher rates of academic failure, lower occupational status, and increased rates of substance misuse, driving accidents and offending.12 On the other hand, ADHD has positive aspects including high energy levels, creative thinking, flexibility and drive. 

    The increasing awareness of ADHD worldwide and the impact of social media, especially TikTok and Buzzfeed quizzes is however, a double-edged sword. While many may benefit from recognising and getting a diagnosis for their symptoms, we need to be careful not to over-medicalise the normal spectrum of human concentration and function. This means that to accurately diagnose ADHD, a careful (and time consuming!) assessment based on DSM 5 criteria is needed.

    Diagnosing ADHD

    To diagnose ADHD, you need to demonstrate five out of the nine symptoms of both inattention and hyperactivity/impulsivity (see Table 1). Symptoms should be present for at least six months in children and to have started before the age of 12. Importantly, symptoms should cause impairment in two functional domains – these include work/occupation; relationships; social interaction; managing money; driving; recreation and leisure; offending behaviour. 

     (click to enlarge)

    Several steps are needed to make a diagnosis. The Adult Self-Reported Scale (ASRS) and Wender Utah score for childhood symptoms are often the first step. The DIVA – Diagnostic Interview for ADHD in adults – looks at the core symptoms required to make a diagnosis. A collateral history from parents, carers or teachers is generally required as well as a psychiatric evaluation for comorbidities. 

    According to the NICE guidelines and the Irish National Clinical Programme for ADHD in adults, ADHD diagnosis and initiation of medication should only be done by a healthcare professional with training and expertise in diagnosing and managing ADHD. Generally, in Ireland this has meant a psychiatrist or clinical psychologist but in fact interested GPs can also specialise in this area.


    We know that in neurodivergent conditions, including ADHD, executive function can be impaired. This term describes the mental processes that enable us to plan, focus attention, remember instructions, and juggle tasks. Clearly these are life skills that we use every day without ever realising it. When these skills are impaired, it can lead to high rates of anxiety, depression, sleep difficulties, substance misuse and even personality disorders (see the ADHD iceberg below)

     (click to enlarge)

    Eating disorders, especially bulimia nervosa and binge eating disorders, are associated with ADHD as the hyperactive symptoms of childhood become diverted into adult restlessness and inability to sit still – imagine being unable to watch a movie without the stimulation of snacks, cigarettes, or caffeine. Food, caffeine, energy drinks and stimulant drugs such as cocaine can be used to self-medicate and get that dopamine ‘hit’. In fact, a warning sign for ADHD could be a patient who uses caffeine and other stimulants to calm themselves down!


    Stimulant medications are the main treatment used in ADHD. They have a remarkably high efficacy rate of 80-88%, which can be rewarding for both the doctor and patient.12 Patients have described starting medication as “putting on glasses and everything coming into focus” or “20 TVs are on and then 19 of them are turned off”. Methylphenidate, which is a controlled drug, is available in short-acting and long-acting forms. The most commonly used long-acting form, Concerta XL, is also the only one currently licensed in adults in Ireland. Lisdexamfetamine, sold as Tyvense, is also a controlled drug. It is important to note that all ADHD medications are licensed in children aged six and up and are considered to be safe in adults too. 

    For those who cannot tolerate stimulants or who have cardiac risk factors, atomoxetine is a non-stimulant, non-controlled medication on the market; however, it has a lower response rate. 

    Once a patient has been started on stimulants and the dose has been titrated to response, the medical monitoring consists of BP, heart rate and weight checks every six months. Blood tests and ECGs are not required as routine monitoring. If blood pressure is >140/90mmHg or heart rate is >120/min on two separate occasions, medication should be reviewed or the dose reduced by the ADHD specialist. When medication is being considered, a personal and family cardiac history should be taken, and cardiac auscultation performed to rule out heart murmurs. ECGs may be indicated if there is a positive cardiac history.13

    Medication diversion

    The risk of diversion of ADHD medications should be considered by the ADHD specialist when initiating a prescription. Anecdotally we have all heard of medications such as Ritalin being sold illegally as study aids or ‘smart drugs’. The Drug Use in Higher Education in Ireland (DUHEI) survey published in 2021 showed that among 12,000 third level students surveyed, 37% had used drugs in the previous 12 months, mostly cannabis and cocaine. Of those who had used drugs, 3.4% admitted to using ‘smart drugs’ (so about 0.01% of all students).14 There is also evidence that by starting ADHD medication you lower the risk of patients self-medicating with stimulants such as cocaine or amphetamines.

    Non-pharmacological treatments

    There are also non-pharmacological treatments useful in ADHD such as ADHD-specific cognitive behavioural therapy, which can be individual or group work. Developing strategies to cope and feeling part of a group can be very powerful therapies. UMAAP – Understanding and Managing Adult ADHD Programme – is a six-week workshop series combining psychoeducation with ACT (acceptance and commitment therapy). This teaches you about neurodivergent brains, executive functioning, inattention and impulsivity, self-care and daily living, emotional regulation  and self-acceptance. This, along with other guided self-help, education and information is available on the ADHD Ireland website

    It is important to note that you do not need to wait to get an official diagnosis of ADHD to use these resources; they are open to all who might be concerned about possible symptoms. 

    The National Clinical Programme (NCP) for ADHD has developed an app which is free to download and contains information and advice on ADHD. It is available from

    ADHD services

    The HSE published the National Clinical Programme Model of Care for Adults with ADHD in 2021.15 However, so far only about 50% of mental health services in the country have an adult ADHD specialist team in place and they are limited to seeing patients with more severe symptoms and significant functional impairment. This means that many adults with ADHD who are coping reasonably well will not be seen in the public system. Long waiting lists are already reported with demand far outstripping resources. 

    Private psychiatrists and psychologists are available to those who can afford them, although due to demand and the nature of the assessment, which is time-consuming, they often also have significant waiting lists. GPs with a special interest in ADHD are starting to look at training, with at least one clinic already seeing patients in the Dublin area. 

    While access to services can be frustrating for both patients and GPs, we are not alone, with the worldwide explosion in ADHD awareness causing similar problems even in countries such the US, which would historically have had more ADHD specialists and supports in place. 

    GP awareness of ADHD symptoms and signposting of support services such as ADHD Ireland will help patients manage their symptoms while awaiting formal diagnosis down the line. 

    With thanks to:

    Mr Martin Finn, ADHD Ireland (Cork); Dr Sarah Carty, ADHD GP Dublin; Dr Margo Wrigley, National Clinical Programme for ADHD in Adults; and Dr Michele Hill


    adhd-in-adults-ncp-model-of-care.pdf (

    NICE Guidelines – NICE (2018). Attention Deficit Hyperactivity Disorder: diagnosis and management.


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