ADHD in adults

05 Sep 07

Psychiatrists Dr Kiriakos Xenitidis, Dr Elena Paliokosta and Dr Stefanos Maltezos recount the controversies over ADHD beyond childhood. Does it exist at all? If it does, how is it best diagnosed and treated?

The efficacy of stimulant and non-stimulant medication and some non-pharmacological interventions in childhood ADHD has been established1. But ADHD is increasingly being recognised as a condition that persists from childhood and adolescence into adulthood, requiring the development of specialist adult services 2,3 . The adult ADHD controversy

Ethical and classification questions have been raised about the validity of ADHD in children – and particularly in adults. Until fairly recently the prevailing view among clinicians and families was that children grow out of ADHD in late adolescence. However, although the exact proportion varies depending on the definition, it is now agreed that at least 50% of children with ADHD continue to suffer from the condition or some symptoms of it in adulthood. The prevalence rates in adulthood are less well established, varying with diagnostic threshold and setting, but rates of 3-5% have been reported.

Media publicity has increased exponentially in recent years. Internet sites (self-help groups, pharmacy sites for online purchase of stimulants or information and support services) have burgeoned. However, there is still a great deal of scepticism among primary care and mental health professionals about the validity of the concept of ADHD in adulthood. The controversy is particularly obvious in the criminal justice system over the question of an individual’s moral responsibility and how it is affected, if at all, by a condition such as ADHD.

The debate as to whether behavioural abnormalities are attributed to defective moral control or a brain disorder is an old one, and theories about the aetiology of ADHD range from a biologically driven genetically determined brain disorder to a social construct of uncertain validity. However, neuropsychological, genetic and neuroimaging studies have increasingly provided evidence for a biological basis for the condition4. How is the controversy affecting patients and GPs?

The concept of ADHD in children and adolescents is widely accepted and paediatricians, child psychiatrists & neurologists and GPs are generally familiar with its diagnosis and treatment. However, medical practitioners in both primary and secondary (and often tertiary) care are less well informed on how ADHD presents in adulthood5. On the other hand, media attention means patients and their families have become increasingly aware and informed about the condition and available treatments. As a result, patients may be better informed than their doctors.

In terms of treatment of adults with ADHD, a number of studies demonstrated the efficacy and safety of stimulant medication (methylphenidate, dexamfetamine), which remain the best studied and most widely used treatments. A wider range of response rates has been found in adults (25% to 78%) compared to children (approximately 70%). A dose-dependent response appears to be well established with higher daily doses (>1mg/kg/day) associated with better response than lower doses. The non-stimulant atomoxetine is an effective alternative usually reserved for stimulant-resistant cases or where stimulants are contraindicated. Other non-stimulant medications used in the treatment of ADHD (venlafaxine, tricyclic antidepressants and bupropion) are generally recommended as second or third-line treatments.

 

Treating ADHD in adults • Involve the patient in treatment decisions. Explain ADHD as a spectrum of severity. • Provide information on available treatments both pharmacotherapy and psychological treatment • No medication for ADHD is licensed in the UK for the treatment of adults. • Duration of pharmacotherapy may be long term. • Refer for appropriate psychological treatments, self-help groups . • Initiate medication taking into account patient’s views. Practical implications for GPs

The diagnosis of ADHD in adults often presents a challenge to the GP because retrospective diagnosis in childhood can be difficult, and needs corroborative history from family members (or indirectly from school reports). It is important to strike a balance between missing the diagnosis in individuals who are significantly affected and overdiagnosing a condition on inadequate grounds.

An important aspect of diagnosing ADHD in adults is to identify other psychiatric/developmental conditions (including mood disorders, anxiety disorders, addiction problems, pervasive developmental disorders, specific learning disabilities and personality disorders) that may co-exist (comorbidities) or mimic (differential diagnosis) ADHD symptoms.

Diagnosing ADHD in adults • Identify age of onset of problems • Establish the presence of ADHD symptoms (including severity and number) in childhood • Estimate degree of impairment in childhood (family, behavioural, educational) as a result of above symptoms • Inquire about current ADHD symptoms (incl uding severity and number) • Establish degree of impairment (occupational, social, academic, family) currently • Consider differential diagnoses and comorbidities (physical and psychiatric)

Neuropsychological correlates of ADHD have been extensively investigated and neuropsychological testing is often used in the clinical situation. However, controversy exists as to the choice of tests and the diagnostic significance of test findings.

Careful physical and psychiatric examination including baseline vital signs, blood tests and electrocardiography, is needed to exclude ADHD features being secondary to a physical disease but also for the purposes of monitoring side-effects of pharmacotherapy.

The NICE guidance on the drug treatment of children with ADHD in the UK says it should be initiated by a specialist6. Once medication is stabilised then follow-up at primary care level can continue. The development of shared care protocols has been recommended and the interface between primary and secondary care and between child and adult services is essential. Guidelines are being developed for adults with ADHD and GPs are more likely to become involved in the management of adults with ADHD 7.

GPs may feel ill-equipped to diagnose and treat ADHD in adults7 but our experience at the Maudsley adult ADHD service suggests they are becoming more confident, at least under specialist follow-up. The most straightforward group of patients is young adults with well established diagnosis of ADHD and good tolerability and efficacy of treatment. This may be the group that GPs would feel more confident in caring for without regular specialist follow-up. On the other end of the spectrum, patients with complex symptomatology, significant comorbidities and social complications (including behavioural problems) should be prioritised for specialist follow-up. There are very few tertiary specialist adult ADHD services. However, as public awareness increases, primary and secondary care physicians’ interest and knowledge of the condition are likely to increase, resulting in a network of local and regional provision for the assessment and treatment of adults with ADHD.

Dr Xenitidis is a consultant psychiatrist at the adult ADHD service at the Maudsley Hospital and the Mental Impairment Evaluation and Treatment Service at the Bethlem Royal Hospital. He is an honorary senior lecturer at the Section of Brain Maturation at the Institute of Psychiatry.

Dr Paliokosta is an honorary research fellow at the section of Brain Maturation at the Institute of Psychiatry, Locum Consultant Psychiatrist at the adult ADHD service and the Southwark Learning Disabilities Team at the Maudsley Hospital.

Dr Maltezos is a trainee in psychiatry at Attica Psychiatric Hospital in Athens, Greece. Honorary research fellow at the section of Brain Maturation in the Institute of Psychiatry and honorary SHO at the Maudsley Hospital.

References :

1 Nutt DJ, Fone K, Asherson P et al. Evidence-based guidelines for management of attention-deficit/hyperactivity disorder in adolescents in transition to adult services and in adults: recommendations from the British Association for Psychopharmacology. Journal of Psychopharmacology 2007;21: 10-41.

2 Asherson P, Chen W, Craddock B et al. Adult attention-deficit hyperactivity disorder: recognition and treatment in general adult psychiatry. British Journal of Psychiatry, 2007;190: 4-5.

3 Taylor E. Development of Clinical Services for Attention Deficit Hyperactivity Disorder. Archives of General Psychiatr 1999;56:1097-1110.

4) Faraone SV, Biederman J. Neurobiology of attention-deficit hyperactivity disorder. Biological Psychiatry 1998;44:951-8.

5) Katragadda S, Schubiner H. ADHD in children adolescents and adults. Primary Care Clinical Office Practice, 2007;34:111.

6) National Institute for Clinical Excellence Attention deficit hyperactivity disorder (ADHD) – methylphenidate, atomoxetine and dexamfetamine (review). Methylphenidate, atomoxetine and dexamfetamine for the treatment of attention deficit hyperactivity disorder in children and adolescents. 2006 Technology Appraisal Guidance No 13 [nice.org.uk]

7) Thapar A, Thapar A. Is primary care ready to take attention deficit hyperactivity disorder? BioMed Central Family Practice 2002:3:7. www.biomedcentral.com/1471-2296/3/7.

Further references
Ball C. Attention deficit hyperactivity disorder (ADHD) and the use of methylphenidate: a survey of the views of general practitioners. Psychiatric Bulletin 2001;25: 301-4.

Barkley R. Attention Deficit Hyperactivity Disorder. 3rd Edition. New York London: The Guildford Press 2006.

Biederman J, Farone SV. Attention Deficit Hyperactivity Disorder. Lancet 2005;366: 237-48.

Biederman J, Newcorn J, Sprichs S. Comorbidity of attention deficit hyperactivity disorder with conduct, depressive, anxiety and other disorders. American Journal of Psychiatry 1991;148:564-77.

Biederman J, Petty C, Fried R et al. Impact of psychometrically defined deficits of executive functioning in adults with attention deficit hyperactivity disorder. American Journal of Psychiatry 2006;163:1730-8.

Faraone SV, Spencer TJ, Montano CB et al. Attention deficit hyperactivity disorder in adults. A survey of current practice in psychiatry and primary care. Archives of Internal Medicine 2004;164:1221-6.

Greydanus DE, Pratt HD, Patel DR. Attention deficit hyperactivity disorder across the lifespan: the child, adolescent and adult. Disease a- Month 2007;53:70-131.

Kates N. Attention deficit disorder in adults. Management in primary care. Canada Family Physician 2005;51:53-9.

Kessler RC, Adler L, Barkley R. The prevalence and correlates of adult ADHD in the United States: results from the National Comorbidity Survey Replication. American Journal of Psychiatry 2006;163: 716-23.

Michelson D, Adler L, Spencer T et al. Atomoxetine in adults with ADHD: two randomised placebo-controlled studies. Biological Psychiatry 2003;53:112-20.

Still GF. Some abnormal psychical conditions in children. Lancet 1902;1008-12, 1077-82,1163-8.

Wender PH, Reimherr FW, Wood DR. Attention deficit disorder (‘minimal brain dysfunction’) in adults. Archives of General Psychiatry 1981;38:449-56.

Wilens TE, Spencer TJ, Biederman J. A review of pharmacotherapy of adults with attention deficit hyperactivity disorder. Journal of Attention Disorders 2002;5:189-202

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