Understanding How Learning Difficulties Often Overlap: Why Dyslexia Rarely Stands Alone

Exploring the Complex Interconnections of Learning Difficulties: Why Dyslexia Seldom Occurs in Isolation

When a child is identified as having Dyslexia, many parents feel a sense of clarity. Finally, there’s a name for the challenges they’ve been seeing. Yet it often becomes clear that Dyslexia doesn’t explain everything. Many children with Dyslexia also experience difficulties with attention, coordination, organisation, maths, memory or language.

In fact, research shows that Dyslexia rarely exists in isolation. Most children with a specific learning difficulty (SpLD) experience more than one area of difficulty. This overlap is known as co-occurrence — and understanding it can make a real difference to how we assess and support each learner.

What Are Specific Learning Difficulties?

SpLDs are differences in how the brain processes certain kinds of information. They include:

• Dyslexia – characterised by difficulties with reading and spelling

• ADHD – challenges with attention, impulse control and organisation

• Developmental Language Disorder (DLD) – difficulties understanding and using spoken language

• Developmental Coordination Disorder (DCD or Dyspraxia) – difficulties with movement and coordination

• Dyscalculia – difficulties with number sense and mathematical reasoning

  
  

Each condition can vary in severity, and many children show features of more than one.

How Often Do These Difficulties Overlap?

Co-occurrence between Dyslexia and other SpLDs is actually the norm rather than the exception. Research suggests that:

• Around 40% of children with Dyslexia also meet the criteria for ADHD.

• Roughly 50% of children with Dyslexia also meet the criteria for Developmental Language Disorder (DLD).

• Up to 63% of children with Dyslexia also have Developmental Coordination Disorder (DCD).

  
  

This overlap makes sense when we consider the shared cognitive features many of these difficulties involve — for example, weaknesses in working memory, processing speed, and executive function (skills such as planning, organising and prioritising).

Shared Challenges Across Different Learning Profiles

Here are a few examples of how these overlaps can appear in everyday life:

• Dyslexia and ADHD: Both can involve slow processing, forgetfulness and working memory weaknesses, which affect reading fluency, written expression and sustained attention.

• Dyslexia and DLD: Both involve phonological processing — the ability to perceive and manipulate sounds in words — which affects reading, spelling and spoken language.

• Dyslexia and DCD: Both may include difficulties with sequencing, coordination and time management, which affect handwriting, organisation and task completion.

• Dyslexia and Dyscalculia: Both may involve weaknesses in working memory and sequencing, making both literacy and numeracy tasks more challenging.

  
  

When a child struggles in one area of learning, it’s important to consider their whole profile rather than focusing on a single label.

Why Do Learning Difficulties Co-Occur?

Researchers have proposed several explanations for why learning differences often overlap. Two useful frameworks are:

1. The Multiple Deficit Model (Pennington, 2006)

This model suggests that learning difficulties arise not from a single cause but from a combination of genetic, neurological, cognitive and environmental factors. Each child’s unique mix of strengths and weaknesses shapes how their learning profile develops.

2. The Cerebellar and Magnocellular Theories

Some research suggests that certain brain areas — such as the cerebellum, which supports coordination and sequencing, and the magnocellular system, which helps process rapid visual and auditory information — may function differently in individuals with SpLDs. These systems are used for many tasks, including movement, timing, reading and attention. This may help explain why Dyslexia, DCD and ADHD so often occur together.

3. The Role of Genetics and Environment

There is strong evidence that learning difficulties often run in families, but genes do not act alone. Environmental factors — such as early language exposure, reading opportunities and emotional wellbeing — can shape how genetic tendencies play out.

A More Helpful Way Forward

For many families, the process of seeking assessment can be confusing. Different professionals may focus on different labels such as Dyslexia, ADHD or DCD, when in reality these conditions often interact.

That’s why many specialists now prefer a multiple factors approach. Rather than assigning several separate diagnoses, we look at the whole child — their cognitive profile, emotional wellbeing and environment — to understand both their challenges and their strengths.

This way of thinking leads to more effective, compassionate support, helping learners build on their natural abilities while addressing specific barriers to learning.

Final Thoughts

Learning difficulties are complex, but they are also a natural part of human diversity. Understanding how they overlap allows parents, teachers and specialists to see the bigger picture — not just a list of difficulties, but the whole child.

By moving beyond single labels and towards a deeper understanding of how learning differences interact, we can offer more personalised, empowering and enduring support.

Further Reading

For those who’d like to explore more, key studies include:

• Pennington, B. (2006). From Single to Multiple Deficit Models of Developmental Disorders

• Carroll et al. (2025). Toward a Consensus on Dyslexia

• Brimo et al. (2021). The Co-occurrence of Neurodevelopmental Problems in Dyslexia

• Reid, G. (2016). Dyslexia – A Practitioner’s Handbook