Bridging the service divide: INVITED COMMENTARY ON... ATTENTION-DEFICIT HYPERACTIVITY DISORDER IN ADULTS

Zwi & York (2004, this issue) present some of the availableevidence supporting adult ADHD as a valid diagnostic entity.Their article shows that there remain many unanswered questionson the suitability of current definitions for adult ADHD, thesize of the potential problem and long-term outcome for patientswith the disorder. While further research is indicated for manycommon psychiatric conditions, the current state of the literatureon adult ADHD is particularly weak, reflecting the general lackof recognition, in both clinical and research practice, of thedisorder in the adult population. For this reason most researchhas been generated by child psychiatrists and psychologistsfollowing up patient groups they have been evaluating from childhood.Although the literature base is not large, the research is entirelyconsistent in demonstrating the continuity of ADHD into adultlife (Faraone et al, 2000a). This is in contrast to the popularview that ADHD is essentially a benign condition that childrengrow out of by the time they are adults, as suggested but notdemonstrated (Barkley, 2000) by the influential paper of Hill & Schoener (1996).

Different perceptions of ADHD

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Different perceptions of ADHD

In fact, the existence of clinically significant ADHD in adultlife is no longer viewed as controversial among large sectionsof the child psychiatric, paediatric and research communities.Child and adolescent psychiatrists are well aware that manyof the children they treat successfully with stimulant medicationcontinue to require treatment beyond late adolescence, whenpsychiatric care is passed over to family doctors and adultpsychiatric services. In addition, they see ADHD in the parentsof the children they are treating, owing to the high familialrate of the condition: around 20% of parents of children withADHD are expected to have ADHD themselves (Faraone et al, 2000b).In contrast, the reluctance of adult psychiatrists to recogniseADHD as a valid disorder beyond the childhood years is surprising,given the considerable psychiatric morbidity that is well documentedto be associated with the disorder in adult life and the existenceof effective treatments in the form of stimulant medication.

There are several reasons why this difference in perceptionbetween child and adult psychiatrists has come about, the mostobvious being that child psychiatrists frequently come intodirect contact with individuals with ADHD and see for themselvesthe often dramatic changes in behaviour and mental state thatresult from the use of stimulants. More fundamental are differencesin training, with child psychiatry focusing on developmentalapproaches in which the onset and progression of behavioursare documented throughout the life span. In contrast, adultpsychiatrists are trained to focus on the development of symptomsand behavioural change from a premorbid baseline. For this reason,symptoms and behaviours associated with ADHD that start in earlychildhood and are persistent and non-fluctuating are viewedas behavioural traits, rather than symptoms of a treatable disorder.Adults face similar problems of diagnostic recognition withother childhood-onset developmental disorders such as autistic-spectrumdisorders, although the treatment implications are less dramaticowing to the absence of targeted drug treatments.

A further difference is that child psychiatry has traditionallyfocused on objective descriptions of behaviours, whereas adultpsychiatry focuses on subjective psychopathology and the mentalstate examination. For this reason, the signs of ADHD givenin the DSM–IV criteria are essentially a list of behavioursthat are maladaptive and inconsistent with the developmentallevel, whereas adults with ADHD have in most cases gained adegree of control over their external behaviours, which aretherefore less overtly disruptive. Nevertheless, adults withADHD describe in detail persistent symptoms that affect theirdaily lives (Box 1). As with other common psychiatric disorderssuch as anxiety and minor depression these symptoms are notqualitatively different from normal every day experiences, butthey become clinically significant if they are more frequentand severe than usual, are uncontrolled and give rise to significantsubjective distress in addition to psychosocial impairmentsat work and in personal relationships.

Box 1. Persistent symptoms of adult ADHD
Internal restlessness,agitation

Uncontrolled and ceaseless thought processes

Poorlycontrolled mood, which is typically volatile and fluctuating

Lowself-esteem

Sleep problems, particularly initial insomnia

Inabilityto focus on tasks that are not immediately rewarding or stimulating

Forgetfulness

Disorganisation,problems with time-keeping, procrastination

The fact that symptoms of adult ADHD overlap with those of personalitydisorder, anxiety and affective disorders and may thereforelead to difficulties in diagnosis and treatment does not makethem any less valid. Importantly, where the symptoms overlapbetween ADHD and adolescent- or adult-onset disorders it isusually possible to make the distinction, since symptoms causingclinical impairment start early in life, persist over time anddo not tend to fluctuate. There may of course be difficultiesin obtaining accurate accounts of childhood behaviours fromadult patients, although parents or older relatives can oftenprovide such information. As in other areas of adult psychiatry,informant reports on current behaviour are useful to delineatethe extent of psychosocial impairments in addition to the subjectivecomplaints of individual patients. Finally, it should be recognisedthat many individuals currently presenting with adult ADHD willnot have received the diagnosis as a child, often because thecondition was less widely recognised when they were young.

Treatment with stimulants

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Treatment with stimulants

Adult psychiatrists are also reluctant to use stimulant medications,a situation that is not helped by the current lack of licensingfor their use in the adult population. This remains the casedespite more than 200 controlled studies of stimulant efficacyand safety in children (Spencer et al, 1996; Schachter et al,2000) and consistent evidence for similar high response ratesamong adults with ADHD (Faraone et al, 2004). Stories of adultsselling stimulants on the black market remain anecdotal andhave little relevance to individuals who are appropriately diagnosedand treated. There is no evidence that tolerance and addictionare a consequence of the appropriate therapeutic use of stimulants,and a number of studies have now demonstrated that the rateof drug misuse and addiction is in fact reduced by up to 50%among individuals treated for ADHD with stimulants (Huss & Lehmkuhl, 2002).

The European Consensus Statement

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The European Consensus Statement

Experience of psychiatrists working with adult ADHD is consistent.The European Network for Adult ADHD has recently been established,in which clinicians from across Europe have come together andare currently working on a consensus statement for the diagnosisand treatment of ADHD in adults (http://www.parnassia-oud.nl/circ_volw2/zp_adhd/euro_netwerk/). What is most striking is the common perspective on the bestway to diagnosis and treat adult ADHD, the impression beingthat direct clinical experience across diverse European countriesis very similar. Overall, the evidence for the validity of adultADHD is strong, and clinical experience suggests that it isa robust and stable concept with clear clinical implications.Nevertheless, this is an area where insufficient systematicresearch has been carried out on presentation, overlap withcomorbid disorders, outcome and response to pharmaceutical andpsychological interventions in this patient group.

References

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