Attention Deficit Hyperactivity Disorder (ADHD)

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterised by executive dysfunction leading to inattention, hyperactivity, impulsivity, and emotional dysregulation. These symptoms are excessive, pervasive, impairing in multiple contexts, and age-inappropriate.

ADHD affects executive functions and self-regulation, contributing to poor professional performance, relationship difficulties, and numerous health risks, collectively predisposing to a diminished quality of life and reduced life expectancy.

ADHD manifests as inattention, hyperactivity (restlessness in adults), disruptive behaviour, and impulsivity. Academic difficulties and relationship problems are frequent. Symptoms must be present for at least six months to a degree greater than others of the same age and must interfere with functioning in at least two settings. Symptoms should be evident before the age of twelve.

ADHD is divided into three presentations:

• Predominantly inattentive (ADHD-PI or ADHD-I)
• Predominantly hyperactive-impulsive (ADHD-PH or ADHD-HI)
• Combined presentation (ADHD-C)

Inattention Symptoms

• Frequently overlooks details or makes careless mistakes
• Difficulty maintaining focus
• Appears not to be listening
• Struggles to finish tasks
• Disorganised
• Reluctant to engage in tasks requiring sustained attention
• Easily distracted
• Forgetful

Hyperactivity-Impulsivity Symptoms

• Fidgeting or squirming
• Trouble sitting still
• Running or climbing inappropriately
• Excessive talking
• Interrupts or intrudes on others

ADHD is diagnosed based on behavioural and mental development assessments, including ruling out other medical or psychiatric problems. Diagnosis often involves feedback from parents and teachers and is typically initiated by concerns raised by a teacher. Standardised rating scales supplement clinical assessments. Imaging studies are used for research but not for diagnosis. DSM-5 criteria are commonly used in North America and Australia, while ICD-10 criteria are used in Europe.

Differential Diagnosis

Differential diagnoses include:

• Anxiety disorders
• Depressive disorders
• Bipolar disorder
• Autism spectrum disorder (ASD)
• Learning disabilities
• Conduct disorder
• Oppositional defiant disorder (ODD)

Management of ADHD often involves medications, behavioural therapies, or a combination. Medications are the most effective treatment, particularly stimulants like methylphenidate and amphetamines, which increase neurotransmission of norepinephrine and dopamine. Non-stimulants like atomoxetine and viloxazine, and alpha-2a agonists like guanfacine XR and clonidine XR, are also used. Behavioural therapies include psychoeducation, cognitive behavioural therapy (CBT), social skills training, and parent management training.

Medications

• Stimulants: Methylphenidate and amphetamine derivatives are first-line treatments, with about 70% of patients responding to the first stimulant tried.
• Non-stimulants: Atomoxetine and viloxazine are FDA-approved and effective for ADHD.
• Alpha-2a Agonists: Guanfacine XR and clonidine XR are effective, especially in children and adolescents.

Behavioural Therapies

Behavioural therapies are recommended for those with mild symptoms or preschool-aged children. Effective therapies include CBT, family therapy, social skills training, and parent management training.

ADHD often coexists with other psychiatric and non-psychiatric conditions. Common psychiatric comorbidities include anxiety, mood disorders, ASD, learning disabilities, ODD, and conduct disorder. Non-psychiatric comorbidities include epilepsy, obesity, asthma, and sleep disorders.

ADHD persists into adulthood in about 30–50% of cases. Individuals often develop coping mechanisms, compensating for symptoms as they mature. Children with ADHD have a higher risk of unintentional injuries, and medication has been shown to reduce these risks. ADHD affects about 5–7% of children and 1–2% of adults globally. Despite higher rates of diagnosis in boys, the condition is often overlooked in girls.

ADHD is a complex and multifaceted disorder requiring a comprehensive approach to diagnosis and management. With proper treatment and support, individuals with ADHD can lead successful and productive lives.

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Self-assessment MCQs (single best answer)

Which of the following is a primary symptom of ADHD?

At what age should symptoms of ADHD be evident for a diagnosis?

Which part of the brain is often affected in individuals with ADHD?

What type of medication is considered first-line treatment for ADHD?

Which of the following is a non-stimulant medication used to treat ADHD?

Which of the following comorbid conditions is most commonly associated with ADHD?

What percentage of children with ADHD continues to exhibit symptoms into adulthood?

Which of the following behavioural therapies is recommended for preschool-aged children with ADHD?

Which diagnostic manual criteria are commonly used in North America to diagnose ADHD?

ADHD is often overlooked in which demographic group?