Attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder relating to the executive functioning of the brain. It is characterised by:

• inattention
• hyperactivity
• impulsivity (Wolraich, 2024)

Attention deficit hyperactivity disorder is most often diagnosed in early childhood, but can be diagnosed in later childhood or adulthood (Kooij et al, 2019). It is one of the most common neuro-behavioural disorders affecting children (Wolraich et al, 2019), with an estimated childhood incidence rate of 5% in the UK (ADHD UK, 2024). Attention deficit hyperactivity disorder has an estimated prevalence of 3–4% in the UK, with a male-to-female ratio of approximately 3:1 (ADHD UK, 2024). 

Symptoms of attention deficit hyperactivity disorder are grouped into hyperactive–impulsive and inattentive symptoms (Table 1).

Attention deficit hyperactivity disorder is grouped into three subtypes:

1. inattentive subtype (20–30% prevalence)
2. hyperactive–impulsive subtype (15% prevalence)
3. combined subtype (50–75% prevalence) (ADHD UK, 2024; National Institute for Health and Care Excellence, 2024)

A person may be considered to have attention deficit hyperactivity disorder if symptoms began in early childhood (under 12 years) and continued for longer than 6 months (National Institute for Health and Care Excellence, 2024). Symptoms must be prevalent in multiple environments, such as home, school and/or work (National Institute for Health and Care Excellence, 2024). Women and men often present differently, with women having a higher likelihood of showing inattentive symptoms and men showing more hyperactive–impulsive symptoms (National Institute for Health and Care Excellence, 2024).

The way symptoms affect a person will depend on their age and stage of life. For example, an adult may not be expected to remain seated in an educational setting, so symptoms would be unrelated to this activity. As the person ages, they may develop different coping or masking strategies, which can alter how symptoms are expressed. For example, an adult may feel internally restless, but will not necessarily demonstrate the physical overactivity seen more often in children (ADHD UK, 2024). Attention span is noted to improve as a person matures, but this will always differ from a person who does not have attention deficit hyperactivity disorder (ADHD UK, 2024).

The International Classification of Diseases Manual 11 (World Health Organization, 2024) includes attention deficit hyperactivity disorder as a distinct diagnosis, positioning it among other neurodevelopmental disorders with the aim of removing the stigma surrounding the condition (Reed et al, 2019). 

The causes of attention deficit hyperactivity disorder are unknown, but several theories have been identified. There is strong evidence supporting a familial link (National Institute for Health and Care Excellence, 2024), as high hereditability has been evidenced through family, twin and adoption studies (Kooij et al, 2019).

Studies show that people with attention deficit hyperactivity disorder show both chemical and physical structural changes in the brain, particularly in the prefrontal cortex, corpus striatum and cerebellum (Mehta et al, 2019). 

Various physical factors have been shown likely to have an impact on the development of attention deficit hyperactivity disorder, including:

• low birth weight
• maternal smoking
• preterm birth
• epilepsy
• toxin exposure (National Institute for Health and Care Excellence, 2024)

Research into exposure to heavy metals and insomnia has shown promising findings (Núñez-Jaramillo et al, 2021); sleep disorders are reported to affect 73–78% of both children and adults with attention deficit hyperactivity disorder (Bijlenga et al, 2019).

While attention deficit hyperactivity disorder is statistically more common in boys than girls, this incidence may be more complex than at first glance, as the differences in how the condition presents in each gender can influence identification and diagnosis (National Institute for Health and Care Excellence, 2024).

National Institute for Health and Care Excellence (2024) guidelines advise that diagnosis of attention deficit hyperactivity disorder must only be given by a specialist with training and expertise in the condition.

Like all diagnoses, it is essential to take a clinical history, encompassing developmental and psychiatric history (National Institute for Health and Care Excellence, 2024). History taking should include multiple sources (eg parents, school partners, carers) and not rely solely on the individual (Adamou, 2024; Wolraich, 2024).

The associated behaviours must have an impact on the person’s wellbeing and functioning in order for diagnosis to be considered (National Institute for Health and Care Excellence, 2024). Additionally, the way in which symptoms manifest will depend on the person’s age and gender (Kooij et al, 2019).

The range of management and treatment interventions is increasing, making treatment selection more challenging (Caye et al, 2019). Treatments can take the form of natural dietary interventions and psychological supports, but most often consist of pharmacological approaches (Caye et al, 2019).

The chosen interventions should be selected based on the individual’s needs and circumstances (ADHD UK, 2024). In terms of non-pharmacological interventions, children may be more suited for family-based therapies and psychoeducation for both the children and their parents or carers (National Institute for Health and Care Excellence, 2024). Interventions can involve schools and a range of professionals, such as psychologists and speech and language therapists (ADHD UK, 2024).

Adult interventions may include:

• interpersonal therapies
• cognitive behavioural therapy
• social skills training
• psychoeducation (one-to-one or group) (ADHD UK, 2024)

Psychological treatments are often used in conjunction with medication (Wolraich, 2024).

The longer-term effects of medications prescribed for attention deficit hyperactivity disorder are unknown (Posner et al, 2020; Coghill et al, 2023). Medications used for attention deficit hyperactivity disorder are either stimulant or non-stimulant in nature; these have complex differences, although their mechanisms of action are not dissimilar (Posner et al, 2020). The efficacy of stimulants is reported to be 85%, with non-stimulants being less effective overall, but with other benefits around mechanism of action (Wolraich, 2024). People and professionals are more cautious with stimulant medications, particularly in childhood, as they have been associated with cardiovascular side effects (Wolraich, 2024).

Nursing and Midwifery Council: standards of proficiency for registered nurses

Part 1: Procedures for assessing people’s needs for person-centred care

1. Use evidence-based, best practice approaches to take a history, observe, recognise and accurately assess people of all ages:

1.1.5 signs of mental and emotional distress including agitation, aggression and challenging behaviour

Part 2: Procedures for the planning, provision and management of person-centred nursing care

11. Procedural competencies required for best practice, evidence-based medicines administration and optimisation

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