When Dyslexia and ADHD Overlap: Understanding the “Double Deficit”

It’s very common for parents to notice more than one challenge at the same time.

A child may struggle with reading, but also have difficulty staying focused, following through on tasks, or managing their work.

This isn’t unusual. In fact, research shows that dyslexia and ADHD frequently occur together.

How Often Do They Overlap?

Studies suggest that 30–50% of individuals with dyslexia also show characteristics of ADHD, and vice versa.

That overlap can make learning feel especially difficult, because the student is navigating challenges in both language processing and attention/executive functioning at the same time.

What Is the “Double Deficit”?

You may hear this referred to as a “double deficit.”

While the term is sometimes used in different ways in research, in practice it describes students who are dealing with two layers of difficulty at once:

• Dyslexia → challenges with decoding, spelling, and processing written language

• ADHD → challenges with attention, working memory, and task management

When these occur together, it’s not just one barrier—it’s two systems that both need support.

Why This Matters for Learning

Each of these affects learning in a different way.

A student with dyslexia may:

• struggle to decode words

• read slowly or inaccurately

• have difficulty with spelling

A student with ADHD may:

• lose focus during instruction

• have trouble holding information in working memory

• struggle to start or complete tasks

When combined, these challenges can compound.

For example, a student might:

• lose focus during a reading lesson

• miss key instruction

• then struggle even more with decoding the words

Over time, this can lead to frustration, avoidance, and a drop in confidence.

What the Research Tells Us

Research consistently shows that dyslexia and ADHD are distinct but related conditions.

They affect different systems in the brain, but they often appear together and can influence each other in how a student learns.

This is why it’s important to identify both, rather than assuming everything stems from just one area.

What Support Looks Like

Students with both dyslexia and ADHD benefit from support in both areas:

• Explicit, structured literacy instruction for reading and spelling

• Clear routines and systems to support attention and task completion

• Small, guided instruction to reduce overload

• Frequent check-ins and feedback

Addressing only one side of the challenge often isn’t enough.

A Simple Way to Think About It

Dyslexia affects how a student processes language.

ADHD affects how a student manages attention and execution.

When both are present, students need support for both learning and doing.

Closing Thought

When a child is struggling, it’s easy to look for a single explanation.

But in many cases, there’s more than one factor at play.

Understanding the overlap between dyslexia and ADHD helps us respond more accurately—and more effectively—to what students actually need.