Adult attention deficit hyperactivity disorder (ADHD) is a key psychiatric disorder. It is characterised by some core clinical featureswhich are hyperactivity, inattention, impulsivity, disorganisation, and low stress tolerance. People with ADHD have several life impediments that characterise their day-to-day lives; these include difficulty starting tasks, struggling to prioritise, and failing to pay attention to details. Enduring chaotic lifestyles, they struggle to keep up with their academic, employment, and relationship commitments.
For the public and for most physicians, ADHD is recognised only as a childhood disorder. But 10-60% of childhood onset ADHD persist into adulthood. Furthermore, about 4.5% of adults have ADHD. The failure to recognise ADHD as an adult problem therefore means it is easily missed in adult psychiatry and neurology clinics. Referring to this in a review published in the journal Psychiatry (Edgmont), David Feifel labelled adult ADHD as the invisible rhinoceros (you must read the article to understand why it is not the elephant in the room). Concerned that many adults with ADHD are misdiagnosed as suffering with anxiety or depression, he urged psychiatrists to routinely screen for adult ADHD in every adult presenting with these disorders.
The scale of the failure to diagnose adult ADHD was emphasised by Laurence Jerome in a letter to the Canadian Journal of Psychiatry. Titled Adult attention-deficit hyperactivity disorder is hard to diagnose and is undertreated, his letter highlighted the finding of the US ADHD National Comorbidity Survey which concluded that most adults with ADHD have ‘never been assessed or treated’. He argued that this oversight places heavy lifetime burdens on adults with ADHD such as impaired activities of daily living, academic underachievement, poor work record, marital breakdown, and dysfunctional parenting. A great burden indeed, but a preventable and treatable one!
How is all this psychiatry relevant to the general neurologist? Well, many manifestations of ADHD are the stuff of the neurology clinic. Cognitive dysfunction for example is prevalent in adult ADHD, and it may present to the neurologist as impaired short term memory, executive dysfunction, impaired verbal learning, and, of course, impaired attention. Sleep related disordersare also frequent in adult ADHD, and these include excessive daytime sleepiness (EDS), restless legs syndrome (RLS), periodic leg movements of sleep (PLMS), and cataplexy. There are also several other neurological co-morbidities of adult ADHD such as epilepsy and learning disability.
It is therefore high time for neurologists and psychiatrists to reveal the invisible rhinoceros!