What you should know about nonverbal learning disorders after Tim Walz announces his son Gus’s diagnosis

• Tim Walz has shared details about his 17-year-old son Gus, who has been diagnosed with ADHD, anxiety disorders and a nonverbal learning disorder
• The disorder affects the way nonverbal communication – such as tone of voice and body language – is processed; this does not mean that people with nonverbal learning disorder cannot speak.
• Diagnosis of this disorder can be difficult because the symptoms are often similar to those of other childhood illnesses.

Democratic vice presidential candidate Tim Walz has revealed that his 17-year-old son Gus suffers from ADHD, anxiety and a nonverbal learning disorder – a diagnosis that Walz calls his son’s “secret power.”

Because the term refers to a nonverbal learning disorder, “people think it means you don’t speak,” says Dr. Vera Feuer, a child and adolescent psychiatrist and assistant vice president of school psychiatry at Northwell Health.

“This couldn’t be further from the truth,” Feuer tells PEOPLE.

According to Feuer, there are two main groups of learning disabilities: verbal and nonverbal.

“These terms refer to the type of skills that are expected. Verbal skills are reading and writing – and verbal learning disabilities affect how people can read, write and interpret information,” she says, citing dyslexia as an example.

These disabilities, she tells PEOPLE, are “detected more quickly” because the symptoms are more obvious.

Nonverbal learning disabilities, on the other hand, “significantly impair some of those nonverbal skills,” such as “reading body language, reading social cues, all the nonverbal areas, nonlinguistic aspects of communication – like facial expression, tone of voice and things like that.”

Specifically: “You may have problems with emotional tone or social interpretation of other people’s tone or signals – interpreting sarcasm, humor, and metaphors.”

“The pragmatics of language might be impaired, but they are obviously fully verbal and able to speak – and that is not the meaning of nonverbal.”

Feuer also points out that nonverbal learning disabilities are “not a subset of autism,” although they say they share “common characteristics.”

“Many children with autism have nonverbal learning difficulties because autism can also affect some skills related to communication – social cues and interpretation, as well as expressing and interpreting emotions.”

“But with autism, there are countless other symptoms and characteristics that are crucial to the diagnosis.”

With nonverbal learning disabilities, Feuer tells PEOPLE, there is “no one particular sign that is a big red flag. It’s difficult to diagnose because you’re ruling out other things as well.”

“It’s harder to detect and more subtle,” she adds. “Children may have difficulty with some math concepts, understanding space and time. And they may have difficulty interpreting social cues, nuances of language and humor – and then they lack some of the other characteristics that children with autism also have, such as sustained interests.”

Children with nonverbal learning difficulties may have trouble “finding directions or finding their way because their brains don’t really understand spatial orientation and distances.”

They may also not understand jokes – and may tend to “take things very literally because they only hear the words and don’t really consider the facial expressions, body language or other social context cues we use to interpret what people are saying.”

She goes on to say that there have long been misunderstandings regarding all learning disorders.

“In general, there is a misconception that learning disabilities are not intelligent, or that you can’t be intelligent if you have a learning disability – and that’s not true. Or that you can’t be intelligent if you have ADHD, and that’s obviously not true,” she says.

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As Walz and his wife Gwen told PEOPLE exclusively in August, Gus is “brilliant, has a keen eye for details that many of us miss, and most importantly, he is a great son and brother to his siblings.”

“We love our Gus,” Tim and Gwen, who also have 23-year-old daughter Hope, told PEOPLE. “We are proud of the man he is growing up to be and we are so excited to have him on this journey with us.”