Attention Deficit Hyperactivity Disorder (ADHD) was thought of as a condition only found in children. Today, we know that although many children diagnosed with ADHD improve with age, the condition can continue into adulthood and, in some cases, is not diagnosed until then.
Attention Deficit Hyperactivity Disorder (ADHD) is defined as a neurodevelopmental condition that affects a person’s ability to regulate attention, behaviour, and impulses. It typically begins in childhood and can persist into adulthood.
The NHS, National Institute for Health and Care Excellence (NICE), classifies ADHD as a persistent pattern of inattention or hyperactivity-impulsivity, or both. Clinicians in the UK use the DSM-5 or ICD-11 diagnostic framework under NICE guidance, which recognises these three ADHD presentations:
In other words, ADHD is a brain-based condition involving differences in the regulation of attention, executive functioning, motivation, and emotional regulation. When it comes to causes of ADHD, they can differ from one person to another. The aetiology is still unclear, but some of the leading causes are considered to be genetic contribution, differences in brain structure and neurotransmitter function, and possible contributions from prenatal factors, such as prematurity or smoking during pregnancy.
It is essential to highlight that a parenting style, laziness, or poor discipline does not cause ADHD. These prejudices can talk individuals out of seeking professional support, whether in childhood or in adulthood.
ADHD involves differences in several interconnected brain systems responsible for attention, executive function, and behavioural regulation. The prefrontal cortex is central to planning, impulse control, working memory, emotional regulation, and decision-making. In ADHD, research consistently shows reduced activation during tasks requiring focus, delayed maturation, and difficulties with sustained attention, task-switching, and inhibitory control. These patterns help explain procrastination, distractibility, and difficulty with long-term planning.
Also, the basal ganglia help manage movement, reward, and motivation. Findings in ADHD include reduced dopamine receptors and transporters in key areas, altered reward processing, and problems with task initiation and sustaining motivation. Dysfunction here explains why people with ADHD often struggle with “boring” tasks but hyperfocus on stimulating ones.
The Default Mode Network is active during mind-wandering, imagination, and internal thoughts. In ADHD, it does not deactivate properly during tasks requiring focus. Moreover, the task-positive network (TPN), which supports concentration, competes with the DMN, which causes drifting attention, daydreaming, and difficulty staying engaged.
ADHD is strongly linked to dysregulation of two key neurotransmitter systems – dopamine and norepinephrine. When these neurotransmitters are dysregulated, the prefrontal cortex cannot efficiently filter distractions, while executive functioning also becomes inconsistent.
The symptoms of ADHD in adults differ from those in children but generally fall into the following categories:
The inability to remain attentive to the task in hand, for example, reading or listening to others, is a common problem and, whilst not disruptive in the same way as other symptoms, can make it difficult in social or work situations.
At the other end of the spectrum, some sufferers become completely absorbed in a task if they are particularly interested in it at the expense of other, more important activities such as eating or sleeping.
Common symptoms include being late for or completely forgetting appointments or deadlines; losing everyday items such as keys or a phone; and a general inability to manage time.
Acting before thinking, rushing into speaking or making decisions without considering the consequences can be distressing for both the sufferer and those around them.
Managing feelings can be problematic, particularly when angry or frustrated. This can lead to being overly sensitive to criticism, low self-esteem and insecurity.
In adults, these feelings are more internalised than in children, for example, racing thoughts, craving excitement and taking excessive risks.
ADHD is a lifelong neurodevelopmental condition, but its expression changes with age. Symptoms do not necessarily disappear, but they evolve as the nervous system matures and life demands shift.
Most of the time, the first signs of ADHD start appearing between the ages 3 and 7. These early childhood signs may include high activity levels, short attention span, impulsive behaviour, emotional outbursts, trouble following multi-step instructions, and rapid shifting between activities.
These symptoms appear even more obviously in structured environments such as schools. A child with ADHD will have difficulty staying seated or focused during lessons, often forget their homework or lose supplies, and struggle with executive skills, among other things.
During adolescence, new challenges emerge related to academic performance, identity development, and social behaviour. When an adult, these symptoms do not simply disappear, but they shift from external behaviours to internal restlessness, overwhelm, and functional difficulties.
When it comes to diagnostic criteria, clinicians must follow NHS and NICE guidelines. These require evidence of symptoms before age 12. When going through the list of symptoms related to ADHD, each must be present in the individual’s life for more than 6 months and cause significant impairment in daily functioning.
One of the reasons why it is so crucial to go through a professional evaluation is that it rules out other conditions, such as anxiety, autism, trauma, and physical disorders, which can have similar symptoms.
In the UK, only a psychiatrist, paediatrician, or a specialist ADHD clinician, including some psychologists and nurse prescribers, can diagnose ADHD.
A formal ADHD assessment is a multi-step clinical evaluation performed by a specialist clinician. It typically includes a full developmental and medical history, a symptom review, interviews with parents/partners and an exploration of functional impairment across settings.
Before the professional evaluation, you might want to take an online ADHD test to get a better overview of your symptoms and how they impact your life. Keep in mind that online assessment tools cannot diagnose you with ADHD. They simply serve as a self-assessment tool to help you understand better your symptoms and decide whether you would benefit from a professional evaluation.
Undiagnosed and untreated, Adult ADHD can have a detrimental effect on both physical and mental health, career and financial difficulties and relationship problems. Some self-help techniques, such as exercising vigorously and regularly, sleeping well and creating an organised environment, can be helpful. However, if you are unable to manage the symptoms of ADHD, it may be time to seek additional help.
Our clinicians can diagnose this condition and will work with you to develop a plan for managing it. This plan may include medication, some self-help techniques, and a referral for therapy, such as Cognitive Behavioural Therapy.
ADHD (Attention Deficit Hyperactivity Disorder) was once thought to only affect children, but it is now widely recognised that ADHD can continue into adulthood. In fact, many adults are only diagnosed with ADHD later in life after years of struggling with symptoms such as inattention, impulsivity, or disorganisation.
Adult ADHD symptoms may include difficulty concentrating, forgetfulness, poor time management, impulsive behaviour, emotional sensitivity, and hyperfocus. Unlike children, adults with ADHD often experience internal restlessness, racing thoughts, and a constant need for stimulation rather than obvious physical hyperactivity.
ADHD in adults can cause serious challenges in everyday life, affecting work performance, relationships, and mental health. Adults with undiagnosed ADHD often struggle with procrastination, missed deadlines, impulsive decisions, and low self-esteem. These difficulties can lead to problems in both personal and professional settings.
Without treatment, adult ADHD can lead to long-term issues such as anxiety, depression, poor job performance, financial instability, and relationship problems. Recognising and treating ADHD in adults is important to reduce these risks and improve quality of life.
Effective treatment for adult ADHD typically includes a combination of approaches. These may involve ADHD medication (such as stimulants or non-stimulants), Cognitive Behavioural Therapy (CBT), and lifestyle changes. Self-help strategies like regular physical activity, structured routines, and good sleep hygiene can also support better focus and emotional regulation. A qualified ADHD clinician can provide diagnosis and create a personalised ADHD treatment plan.
