Recommendations for research

In 2008, the Guideline Development Group made 5 recommendations for research. As part of the 2016 update, the standing committee made 2 additional recommendations for research on the effectiveness of 'few food' diets and the effectiveness of dietary restriction of artificial colouring and preservatives (details can be found in the addendum).

1 Grounds for diagnosis of ADHD in adults

What is the prevalence of inattention, impulsivity and hyperactivity/restlessness in males and females in the adult population?

How far do the core symptoms of inattention, impulsivity and hyperactivity/restlessness cluster together?

To what extent are the core symptoms comorbid with other forms of mental disturbance?

To what extent are the core symptoms associated with neuropsychological and social impairment? This would be best conducted as an epidemiological survey.

Why this is important

There is evidence that ADHD symptoms can persist into adulthood and cause impairment, but there are no clear conclusions about the level of ADHD symptoms in adults that should be considered as grounds for intervention, or whether symptoms take a different form in adulthood. The costs to society and to the affected people and their families make it pressing to know whether, and how far, services should be expanded to meet the needs of this group.

2 Discontinuation of drug treatment

Are there any benefits or disadvantages to the extended/long‑term use of methylphenidate compared with its discontinuation at least 18 months after starting treatment? To what extent does continuing drug treatment beyond 18 months alter quality of life, core ADHD symptoms, associated symptoms including emotional lability, potential adverse effects of continued drug treatment and neuropsychological function? This would be best conducted as a drug discontinuation randomised controlled trial.

Why this is important

Methylphenidate is often given for periods of years without good evidence of whether prolonged therapy is effective or safe. Methylphenidate is also typically discontinued in late adolescence; evidence is required of the benefit of continued prescribing in this age group.

3 Effectiveness of group‑based parent training

Are group-based behavioural parent‑training/education methods more effective than drug treatment in school‑age children and young people with ADHD in terms of symptoms, quality of life and cost effectiveness? This would be best evaluated by a head‑to‑head randomised controlled trial.

Why this is important

The evidence for the effect of group‑based parent‑training/education programmes is largely based on studies of younger children. These programmes are an important part of the management of ADHD although their cost effectiveness is not clear for older children and adolescents.

4 Effectiveness of non-drug treatments for adults with ADHD

Are non-drug treatments (including focused psychological treatments and supportive approaches such as coaching) more effective than drug treatment (methylphenidate) in terms of symptoms, quality of life, cost effectiveness, drug misuse and other coexisting conditions, and the cost of health, forensic and criminal justice services, in the treatment of adults with ADHD? This would be best conducted as a randomised controlled trial.

Why this is important

Currently there is good evidence supporting the effectiveness of methylphenidate in people with ADHD symptoms and associated impairment. However, there is insufficient evidence on whether non‑drug treatments could have specific advantages in some important aspects of the life of a person with ADHD. Given the strong association of ADHD in adults with substance misuse, personality disorder and involvement in the criminal justice system, a health economic approach would be essential.

5 Effect of providing training in behavioural management of ADHD for teachers

Does the training of teachers in the behavioural management of children with ADHD in primary and secondary schools improve ADHD symptoms and academic attainment, the teacher's experience of stress in the classroom and the impact of ADHD on other pupils when compared with current education methods? This would be best conducted as a randomised trial.

Why this is important

Secondary school is typically a different environment from primary school, particularly in terms of organisation of the daily timetable and expectations of the increasing independence of pupils. These factors may have an adverse impact on young people with ADHD, but the effect of understanding and modifying this impact has not yet been researched. The potential for teachers to take a more active role in the behavioural management of primary and secondary school children with ADHD shows some significant promise in at least one trial. The benefits of examining primary and secondary education, compared with education as usual, and examining the broader impact on the child, the teacher and the wider classroom, would significantly improve future versions of this guideline.

6 Effectiveness of 'few food' diets as a treatment for ADHD in children and young people

What is the long-term clinical and cost effectiveness of 'few food' diets, with managed reintroduction of restricted foods, in the management of ADHD in children and young people?

Why is this important?

The Committee reviewed evidence on 'few food' diets in the management of ADHD in children and young people. The Committee decided that although such an intervention may result in a reduction in ADHD symptoms in the short term for children aged 4–8 years, the evidence of a positive effect was not strong enough to recommend this very restrictive diet, given the potential for nutritional harm and the additional costs of the dietary support that would be necessary to implement this diet safely. A randomised controlled trial is needed to investigate the long‑term clinical effectiveness, cost effectiveness and feasibility of this type of dietary intervention. Outcomes should be assessed by an assessor blinded to treatment allocation.

7 Effectiveness of dietary restriction of artificial colouring and preservatives as a treatment for ADHD in children and young people

What is the long-term effectiveness of dietary restriction of artificial colouring and preservatives in the management of ADHD in children and young people?

Why is this important?

We searched for evidence on restriction or elimination diets in the management of ADHD in children and young people. No studies were found on eliminating artificial colouring or preservatives, despite a recommendation in the original guideline that elimination of artificial colouring or additives should not be advised for children or young people with ADHD. However, feedback from stakeholders and topic expert committee members indicated that this is an important clinical question, and that evidence suggests that artificial colouring and preservatives may contribute to hyperactive behaviour in other population groups. A randomised controlled trial is needed to investigate the long‑term clinical and cost effectiveness and feasibility of this type of dietary intervention. Outcomes should be assessed by an assessor blinded to treatment allocation.

  • National Institute for Health and Care Excellence (NICE)