Is ADHD a valid diagnosis in adults? NoBMJ 2010; 340 doi: https://doi.org/10.1136/bmj.c547 (Published 26 March 2010) Cite this as: BMJ 2010;340:c547
- Joanna Moncrieff, senior lecturer and honorary consultant psychiatrist1,
- Sami Timimi, consultant child and adolescent psychiatrist and visiting professor of child and adolescent psychiatry, Lincoln University2
- 1University College London and North East London Mental Health Trust, UCL Department of Mental Health Sciences, London W1W 7EJ
- 2Lincolnshire Partnership NHS Foundation Trust, Sleaford, NG34 8QA
- Correspondence to: J Moncrieff
- Accepted 14 December 2009
Interest in adult attention deficit hyperactivity disorder (ADHD) has grown rapidly in some countries because drug companies have realised that it provides an “expanding and lucrative market” for stimulants and related drugs.1 They have promoted the concept by suggesting that common behaviours, such as forgetting car keys, may be symptoms,2 and many adults are being diagnosed who were never diagnosed as children. We explain why little more than aggressive marketing is available to support adult ADHD.
Whether childhood ADHD is a valid and useful diagnosis is disputed on many grounds, including lack of physical or psychological markers, high comorbidity rates, difficulty in differentiating normal symptoms from pathological ones, inconsistent clustering of symptoms, differing cultural perceptions and variation of diagnosis across sex and class,3 and serious adverse outcomes being more strongly related to co-occurring problems such as conduct disorder and familial conflict.4 Even if we accept childhood ADHD as valid, the validity of adult ADHD does not automatically follow. ADHD has its origins as a childhood disorder. Symptoms such as impulsivity and hyperactivity are defined and understood as developmental problems, and field trials for developing the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, criteria for ADHD used children and adolescents only.5 Definitions of adult ADHD include numerous aspects of mental functioning and behaviour that are not usually examined in children—such as mood swings, irritability, stress intolerance, anger, and risk taking—and play down central features of childhood ADHD such as hyperactivity.6 Moreover, nearly 90% of adults diagnosed with ADHD have at least one other psychiatric diagnosis, and many have two,7 pointing to high comorbidity with more established diagnoses. Recent guidelines from the National Institute for Health and Clinical Excellence (NICE) noted that adult ADHD overlaps with various personality disorders, as well as depression, anxiety, and modern conceptions of bipolar and bipolar spectrum disorder.8 Although some research suggests that adult ADHD symptoms are associated with academic impairment and problems with work and driving,9 we do not know how much of this is just normal variation or is related to comorbid conditions.
Longstanding problematic patterns of behaviour in adults are usually referred to as personality traits or disorders. A more robust evidence base is surely required before accepting a concept such as adult ADHD, which departs from established views of the nature of behavioural problems, has a large overlap with other diagnoses, and has only a tenuous association with the childhood disorder.
A major driver behind the increased popularity of diagnosing adult ADHD is the idea that it responds to treatment with stimulant drugs. Studies in children show that stimulants can improve attention and reduce activity levels in the short term, but that they have little impact on quality of life or academic performance and initial beneficial effects are not sustained on long term follow-up.10 Even the NICE guidelines recommend restricting stimulant use to children with the most severe symptoms, or those in whom other treatments have failed.8 NICE, however, recommends stimulants as first line treatment for everyone with adult ADHD. This recommendation was made on the basis of three randomised controlled trials, two of which were conducted by a group at Harvard, which was found to have substantial conflicts of interests.11 The third was a small crossover study of three weeks’ duration that comprised 45 subjects. A recent meta-analysis of a larger group of methylphenidate studies found no significant difference between drug and placebo in studies that used the generally superior parallel group design (effect size 0.36, 95% confidence interval −0.17 to 0.88), as opposed to crossover studies. It also showed that trials by the Harvard group reported substantially higher effects than others.12 The only long term drug trial yet published (atomoxetine) was negative for its main outcomes at six months.13 With regard to risks, stimulants are known to increase heart rate and blood pressure, and prolonged recreational use can result in myocardial infarction and stroke.14
Physical and psychological dependence are a further potential problem, and in countries with high rates of stimulant prescribing, much is diverted on to the black market.15 Popularising the diagnosis of adult ADHD also encourages people to regard longstanding behavioural problems as amenable to a quick fix, thus introducing, undebated, a form of cosmetic psychopharmacology that fits into our increasingly hyperactive lifestyles but at a price of distancing us from our own psychosocial resources and abilities.
The speed with which the diagnosis of adult ADHD has been accepted, its vagueness, and the lack of evidence for the usefulness of specific treatments indicate that it is the latest of several medical and psychiatric fashions, which have been fuelled by the interests of the drugs industry. More research and debate is needed before the diagnosis is embraced and widespread stimulant prescribing becomes the norm, otherwise we may face a scandal similar to the overprescribing of benzodiazepines.
Cite this as: BMJ 2010;340:c547
Both authors have completed the Unified Competing Interest form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: 1) no financial support for the submitted work; 2) no relationships with any companies that may have an interest in the submitted work in the past three years; 3) their spouses, partners, or children have no financial relationships that may be relevant to the submitted work; 4) they are members of the Critical Psychiatry Network.
Provenance and peer review: Not commissioned; externally peer reviewed.