Ask the Experts

What Is Slow Processing Speed? Is It the Same as ADHD?

Q: “I think my child has slow processing speed or ADHD. Whom should I see to have him evaluated, and what tests should be done?”

What is slow processing speed?

Slow processing speed is not a formal learning disability, but it can play a part in learning and attention issues like dyslexia, attention deficit disorder (ADHD or ADD), dysgraphia, dyscalculia, and auditory processing disorder.

Slow processing speed means that a child cannot keep up with the pace of classroom learning, is last to finish tests, or has problems in following directions. At home, slow processing speed means homework that takes forever to do, frustration with written assignments, and difficulty getting ready for school in the morning.

Many kids with slow processing speed are very smart and capable, but aren’t reaching their academic potential. If this is the case with your child, get a comprehensive evaluation done by a child clinical psychologist or neuropsychologist.

How is slow processing speed assessed?

Many tools are used to assess slow processing speed. A foundation I recommend is the Wechsler Intelligence Scale for Children (WISC-V). Experts frequently use the WISC-V subtests Coding, Cancellation, and Symbol Search to assess processing speed. The Coding subtest also provides feedback about dysgraphia and challenges with slow handwriting.

[Quiz: Do You Know the Difference Between ADHD and Learning Disabilities?]

The NEPSY-II provides a variety of measures to assess processing speed and fluency, including the Speeded Naming Test and the Word Generation Test. Educational testing, such as the fluency measures on the WIAT-III and the Woodcock-Johnson III Tests of Achievement, are helpful in determining whether slow processing speed affects the ability to complete simple academic tasks in a timely fashion.