Addressing the lack of studies in attention-deficit/hyperactivity disorder in adults

Abstract

Attention-deficit/hyperactivity disorder (ADHD) is commonly known to occur during childhood, characterized by excessive inattention and/or hyperactivity and impulsivity as well as lack of emotional self-control and motivation. The prevalence of adult ADHD in the general population is estimated to be between 2–5%. The aim of this review is to provide an overview regarding current controversies related to ADHD within the adult population. The concept of ADHD in adults has been questioned and criticized by professionals over the last years. Overall, adult ADHD is well evidenced based on epidemiological data, genetic data, neuroimaging, psychosocial impairment and treatment effectiveness. Although, research within this field has been significantly improved, suggestions for future research are provided, in order to be able to clarify the remaining questions regarding this disorder throughout adulthood. One of the most important changes to be made in the near future should be to increase educational training on ADHD in adults.

Keywords::

• ADHD
• adult
• clinical impairment
• diagnosis
• evidence
• genetics
• review
• treatment

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Erratum

Financial & competing interests disclosure

JA Ramos-Quiroga was on the speakers’ bureau and/or acted as consultant for Eli-Lilly, Janssen-Cilag, Novartis, Shire, Lundbeck, Almirall and Rubió in the last 3 years. He also received travel awards (air tickets + hotel) for taking part in psychiatric meetings from Janssen-Cilag, Rubió, Shire and Eli- Lilly. The ADHD Program chaired by him received unrestricted educational and research support from the following pharmaceutical companies in the last 3 years: Eli-Lilly, Janssen- Cilag, Shire and RM Casas was on the speakers’ bureau and/or acted as consultant for Eli-Lilly, Janssen-Cilag and Shire in the last 3 years. V Nasillo and F Fernández-Aranda have no conflict of interest. Partial financial support was received from Ministerio de Ciencia y Tecnología, “Instituto de Salud Carlos III-FIS” (PI12/01139). Partial financial support was received from AGAUR (2009SGR1554). CIBERFisiopatología de la Obesidad y Nutrición (CIBERobn) is an initiative of ISCIII. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Attention-deficit/hyperactivity disorder (ADHD) is a disorder that typically begins at childhood, with a chronic evolution in main parts of the patient’s body. For that, a significant part of the affected children continue manifesting symptoms throughout adulthood.

• Much of the evidence to date suggests that among adolescents and adults, ADHD is underrecognized and undertreated. Epidemiological studies showed a prevalence of ADHD in adults up to 4.4% in general population.

• Although numerous molecular studies focused on adult ADHD, where results were similar to those obtained in genetic studies with children and adolescent samples; in others, the findings were not in concordance.

• Neuroimaging studies conducted in adults with ADHD have shown alterations in the brain at the structural and functional levels, and also in terms of connectivity. These findings have been observed mainly in the inferior frontal and dorsolateral prefrontal cortex, as well as in striatal, anterior cingulate, parietotemporal and cerebellar regions.

• Studies on adults with ADHD have shown that its presence is associated with a significant impairment on academic achievement, work adjustment, interpersonal relationships, drug use, greater frequency of traffic accidents and crime problems.

• The publication of the ADHD diagnostic and statistical manual of mental disorder-5 criteria has generated new criticism. However, the changes introduced in the diagnostic and statistical manual of mental disorder-5 for the diagnosis of ADHD in adults, although founded in empirical research, are still restrictive.

• There are reliable psychometric instruments for diagnostic assessment of ADHD in adults, as diagnostic interview for ADHD in adults, Conners adult ADHD diagnostic interview for DSM-IV, MINI-Plus or psychiatric research interview for substance and mental disorders.

• Pharmacotherapy for adults with ADHD has been shown to be effective. There are now randomized, placebo-controlled clinical trials and meta-analysis showing the effectiveness and safety of methylphenidate and amphetamines and atomoxetine for adults with ADHD.

• Cognitive behavioral therapy has proven to be the most effective psychological approach for treating the symptoms of adult ADHD and comorbid symptoms of anxiety, depression and emotional instability approach.

• It is absolutely essential to include education of ADHD in adults in the pre-degree programs in Universities because of the high prevalence of the disorder and the severe consequences of misdiagnosis.