Dyslexia and ADHD – Understanding the Differences, Similarities and Overlap

 

Why difficulties with reading, concentration and organisation aren’t always what they seem

Dyslexia and Attention Deficit Hyperactivity Disorder (ADHD) are two distinct neurodevelopmental conditions, yet they can sometimes look remarkably similar in everyday life.

Someone who struggles to concentrate when reading, frequently makes spelling mistakes, loses track of instructions or takes longer than expected to complete written work might have dyslexia, ADHD, or a combination of both.

Understanding the differences is important, particularly when considering an assessment, because identifying the underlying reasons for these difficulties can help ensure that someone receives the right support.

At Clear Sky Therapies, we recognise the importance of looking beyond individual symptoms to understand the broader picture of a person’s cognitive, developmental and emotional functioning.

What is Dyslexia?

Dyslexia is a specific learning difficulty that primarily affects the development of accurate and fluent word reading and spelling.

It is commonly associated with difficulties in phonological processing — the ability to recognise, distinguish and manipulate the sounds that make up spoken language.

Someone with dyslexia may experience:

• Difficulty reading unfamiliar words accurately.
• Slow, effortful reading, even when they understand the subject matter.
• Persistent spelling difficulties.
• Problems remembering sequences of letters or sounds.
• Difficulty translating thoughts into written language.
• Greater mental fatigue when reading or writing for extended periods.

Importantly, dyslexia is not an indication of low intelligence. Many people with dyslexia have strong verbal reasoning, creativity, problem-solving abilities and well-developed knowledge in their areas of interest.

Dyslexia can also remain unidentified until adulthood, particularly in individuals who have developed effective compensatory strategies or who have performed well academically despite the additional effort required.

What is ADHD?

ADHD is a neurodevelopmental condition characterised by difficulties in attention regulation and/or hyperactivity-impulsivity that affect every day functioning.

Although ADHD is frequently associated with difficulties concentrating, its impact is generally broader than attention alone, and inattention is less relevant than issues in being able to focus when something is not exciting, novel or urgent.

ADHD additionally affects executive functioning, including the ability to organise, plan, initiate tasks, regulate attention, manage time and hold information in working memory.

Someone with ADHD may experience:

• Difficulty sustaining attention, particularly during repetitive or less engaging activities.
• Frequently losing belongings or forgetting important information.
• Difficulty starting or completing tasks.
• Poor time management and underestimating how long activities will take.
• Becoming distracted by thoughts, sounds or surrounding activity.
• Impulsivity, restlessness or difficulty regulating activity levels.
• Inconsistent performance, sometimes working extremely effectively and at other times struggling with relatively straightforward tasks.

ADHD can also affect reading and writing, but often for reasons that differ from those associated with dyslexia.

For example, someone with ADHD may be perfectly capable of decoding written words but repeatedly lose their place, skim paragraphs, overlook information or realise that they have read several pages without absorbing the meaning.

Dyslexia and ADHD: Where are the main differences?

Although there can be considerable overlap, certain patterns may help distinguish between the two conditions.

1. Reading Accuracy and Fluency

In dyslexia, difficulties commonly involve the mechanics of reading itself.

An individual may misread words, struggle to decode unfamiliar vocabulary or need considerably more time to read accurately.

These difficulties can remain present even when the person is motivated, interested and concentrating carefully.

In ADHD, basic word-reading accuracy may be relatively well developed. However, attention can fluctuate, resulting in skipped words, missed lines, careless errors or difficulty retaining what has been read.

The key distinction: Dyslexia commonly affects how efficiently written words are recognised and decoded, whereas ADHD may interfere with how consistently someone attends to and processes written information.

Of course, someone can experience both difficulties simultaneously.

2. Spelling and Written Work

Spelling difficulties are often particularly noticeable in dyslexia.

Errors may reflect difficulties with the relationship between sounds and letters, spelling patterns or the accurate retrieval of word forms.

Someone may repeatedly misspell familiar words despite considerable practice.

In ADHD, spelling errors may be more closely associated with rushing, inconsistent attention or insufficient proofreading.

A person may know how to spell a word but make mistakes when distracted or working quickly.

Written work can also be affected differently.

Someone with dyslexia may struggle with spelling, transcription and the mechanics of producing written language.

Someone with ADHD may have good literacy skills but find it difficult to organise ideas, plan an essay, maintain a coherent structure or complete the work within the available time.

When both conditions are present, difficulties with literacy and executive functioning can compound one another.

3. Working Memory

Working memory refers to our ability to hold and manipulate information mentally over short periods.

Both dyslexia and ADHD can be associated with working-memory difficulties, although the patterns may differ.

In dyslexia, difficulties may be particularly noticeable when information involves speech sounds, verbal sequences or phonological processing.

In ADHD, working-memory difficulties can be broader and may be influenced by inconsistent attention, distractibility and executive functioning.

For example, someone with ADHD might forget what they were about to do after being interrupted, while someone with dyslexia might struggle to retain a sequence of unfamiliar verbal information.

However, these examples are not exclusive to either condition, and working-memory performance alone cannot reliably distinguish between dyslexia and ADHD.

4. Listening and Reading Comprehension

One useful area to explore is whether someone understands information more effectively when it is presented verbally rather than in writing.

An individual with dyslexia may demonstrate excellent understanding when listening to an explanation but struggle to extract the same information from written text.

This may be because the effort involved in decoding words leaves fewer cognitive resources available for comprehension.

Someone with ADHD may understand both spoken and written information well when sufficiently engaged, but miss important details because their attention has drifted.

For example, they might listen to a conversation yet realise afterwards that they have missed part of what was said.

When dyslexia and ADHD coexist, difficulties with reading comprehension may reflect both the effort required to decode words and fluctuations in attention.

5. Organisation, Time Management and Everyday Forgetfulness

This is an area where ADHD often becomes more apparent.

Persistent difficulties with time management, planning, organisation, remembering appointments and keeping track of belongings are commonly associated with ADHD.

Although someone with dyslexia may develop organisational difficulties, particularly around demanding literacy-based activities, these broader executive-functioning problems are not defining features of dyslexia.

Consider someone who regularly:

• Loses their keys, phone or wallet.
• Forgets appointments.
• Underestimates how long tasks will take.
• Struggles to begin everyday activities.
• Leaves tasks unfinished.
• Becomes distracted during conversations.

If these difficulties occur across multiple settings and are not limited to reading or writing, ADHD may warrant consideration.

However, such difficulties can also arise from anxiety, poor sleep, depression, stress or other factors, so they should not automatically be attributed to ADHD.

Can Someone Have Both Dyslexia and ADHD?

Yes. Dyslexia and ADHD frequently co-occur, and having one does not exclude the possibility of the other.

Research suggests that the overlap is substantial, although estimates vary depending on the populations studied and the diagnostic methods used.

Both conditions have developmental origins, and there may be shared cognitive and genetic influences.

When someone has both dyslexia and ADHD, the combined impact can be particularly challenging.

For example, a student may find reading slow and mentally demanding because of dyslexia, while also struggling to sustain attention because of ADHD.

Similarly, written assignments may be difficult because of spelling and transcription problems, alongside difficulties planning, organising and completing the work.

The result can be considerable frustration, fatigue and an understandable reluctance to engage with activities that repeatedly expose these difficulties.

Over time, some individuals develop feelings of inadequacy or conclude that they are simply not trying hard enough.

Recognising that two distinct conditions may be contributing can therefore be important, both practically and psychologically.

How Can You Tell Whether Difficulties Are Due to Dyslexia, ADHD or Both?

One of the most useful approaches is to explore whether the difficulties remain when the demands associated with one condition are reduced.

Consider two questions.

Question One: What happens when reading and writing are removed?

Imagine someone who struggles to concentrate when completing written assignments.

Would they continue to experience significant problems with attention, organisation, time management and task completion if reading and writing were removed from the situation?

If the answer is yes, this may suggest broader executive-functioning difficulties consistent with ADHD.

For example, someone who struggles equally with managing household responsibilities, remembering appointments, organising personal belongings and completing practical tasks may be experiencing difficulties extending beyond literacy.

Question Two: What happens when attention is well supported?

Now consider someone whose attention and executive functioning are well supported.

Would they still experience significant difficulties with reading accuracy, spelling or decoding unfamiliar words?

If so, this may suggest an independent literacy difficulty such as dyslexia.

These are useful clinical questions rather than diagnostic tests. They help explore the underlying mechanisms, but a comprehensive assessment is needed to reach reliable conclusions.

Why childhood history matters

Both dyslexia and ADHD are developmental conditions, meaning that relevant difficulties generally emerge during childhood, even if they are not recognised until much later.

In dyslexia, there may be a history of difficulties learning letter-sound relationships, developing fluent reading or acquiring accurate spelling.

In ADHD, childhood indicators may include persistent difficulties with attention, organisation, impulsivity, activity regulation or completing tasks.

However, childhood presentations can vary considerably.

Some individuals are academically successful, quiet, compliant or highly motivated, which can make their difficulties less obvious.

Others receive considerable support from parents or teachers, allowing them to manage effectively until the demands of secondary school, university or adult life increase.

School reports, developmental history and information from people who knew the individual during childhood can therefore provide valuable evidence.

The emotional impact of unrecognised Dyslexia and ADHD

An important aspect of both conditions is the emotional impact that can develop when difficulties remain unexplained.

Individuals may spend years wondering why activities that appear straightforward for others require so much effort.

They may have been described as careless, disorganised, lazy or insufficiently motivated.

For some, repeated experiences of frustration or perceived failure can contribute to anxiety, low self-esteem, avoidance or perfectionism.

Adults may have developed sophisticated strategies to compensate for their difficulties, but these can come at a considerable personal cost.

Understanding the underlying reasons for longstanding difficulties can therefore be valuable beyond the practical implications of diagnosis.

It may allow someone to reconsider earlier experiences with greater understanding and develop a more compassionate view of themselves.

What should an assessment consider?

Where dyslexia and ADHD are both possibilities, it is important that assessment does not focus too narrowly on individual symptoms.

A comprehensive evaluation should consider:

• Developmental and educational history.
• The nature and persistence of reading and spelling difficulties.
• Attention and executive functioning across different settings.
• Working memory and other relevant cognitive processes.
• The impact on education, employment and everyday life.
• The possibility of co-occurring conditions.
• Alternative explanations, including anxiety, mood difficulties, sleep problems and other factors.

Formal dyslexia assessment and ADHD assessment involve different procedures and areas of expertise.

An ADHD assessment does not automatically establish whether someone has dyslexia, and a dyslexia assessment does not establish whether someone meets diagnostic criteria for ADHD.

Where both conditions are suspected, it may be appropriate to consider separate but complementary assessments.

What Support Can Help?

The most appropriate support depends on the individual’s particular difficulties.

For dyslexia, support might include specialist literacy intervention, assistive technology, text-to-speech software, accessible written materials and appropriate educational or workplace adjustments.

For ADHD, support may involve strategies for planning, time management, task initiation, organisation and attention regulation. Depending on individual circumstances, medication and psychological interventions may also be considered.

When both conditions are present, support is likely to be most effective when it addresses both literacy-related difficulties and broader executive-functioning needs.

Importantly, support should be tailored to the individual’s functional needs rather than relying solely on diagnostic labels.

Final Thoughts: Understanding the Whole Person

Dyslexia and ADHD can share a number of outwardly similar features, particularly when difficulties involve reading, concentration, working memory and completing written tasks.

However, the underlying reasons for these difficulties may be quite different.

Dyslexia primarily involves difficulties with the development of accurate and fluent word reading and spelling, while ADHD involves broader difficulties with attention regulation and/or hyperactivity-impulsivity, often affecting executive functioning.

For some individuals, both conditions are present, creating a more complex picture.

The key is not simply to identify whether someone struggles with reading or concentration, but to understand why those difficulties occur, when they began, and how they affect every day functioning.

A thoughtful assessment can help clarify these differences and identify the most appropriate forms of support.

ADHD Assessments and Support at Clear Sky Therapies

At Clear Sky Therapies, we provide ADHD assessments for adolescents and adults, alongside autism assessments and psychological therapy.

Our approach considers developmental history, everyday functioning, individual strengths and the possibility of overlapping or co-occurring difficulties.

Where dyslexia is suspected, we can discuss whether a specialist assessment would be helpful alongside consideration of ADHD.

If you would like to explore whether ADHD may be contributing to difficulties with concentration, organisation or everyday functioning, please contact Clear Sky Therapies to discuss the available assessment options.

Website: www.clearskytherapies.co.uk

Recommended references

• BritishDyslexia Association — information on dyslexia, assessment and
• NICEGuideline NG87 — ADHD diagnosis and
• PubMedresearch on dyslexia and ADHD co-occurrence — relevant research

 

Dyslexia and ADHD