ADHD Weekly, May 21, 2026

You may have started working with a provider to answer the question: Could this be ADHD? But over time, another question may come up: Is something else going on?

For the majority of children and adults who have ADHD, the answer will be yes. About two-thirds of people diagnosed with ADHD have at least one co-occurring condition, such as anxiety, depression, a learning disorder, or a sleep disorder. Continuing research finds that this kind of overlap is common across mental health conditions more broadly. In fact, coexisting conditions appear to be the rule, not the exception, meaning many people experience more than one condition at the same time.

Understanding these possible connections can be an important step toward getting the right support—not just for ADHD symptoms, but for the whole picture of what you or your child may be experiencing.

ADHD plus

Many people have what could be called “ADHD plus”—ADHD and another condition that may need to be recognized, treated, and managed at the same time.

In one large study, researchers reviewed the mental health records of six million people in Denmark over a period of up to seventeen years. They found that those diagnosed with one mental health condition were more likely to have, or later develop, a secondary condition. For many conditions, the researchers were able to estimate the likelihood that someone would receive a second diagnosis within a set number of years.

For example, they found that among people who developed a mood disorder before age twenty, 40 percent of men and 50 percent of women later developed a secondary condition within the next fifteen years.

This kind of overlap is common for people with ADHD. Among adults with ADHD, about 47 percent also have depression and 53 percent have anxiety. Among children with ADHD, about 14 percent also have depression and 30 percent have anxiety. Other frequently diagnosed co-occurring conditions include mood disorders, tic disorders, and sleep disorders. Learning disabilities, while not mental health conditions, also frequently occur with ADHD.

Recognizing these patterns matters because symptoms can overlap, intensify one another, or make it harder to know what kind of support is needed. For many people, effective care means looking at the whole picture—not just ADHD symptoms on their own.

Creating a map of mental health

Researchers are also looking more closely at how different mental health conditions connect with one another over time.

John McGrath, MD, senior author of the Denmark study and director of the Queensland Centre for Mental Health Research in Australia, compared the research to creating a detailed map of mental health conditions.

“It’s like we developed Google Maps for every type of mental disorder, and we’ve gone down to the street level,” he says. “The labels we use to describe mental illnesses are interim, temporary placeholders. They describe surface-level symptoms, but many of these disorders go together.”

That kind of mapping may eventually help clinicians better understand which co-occurring conditions are more likely to appear based on a person’s diagnosis, age, and sex. Researchers hope this information can lead to more tailored care, better education about self-management, and treatment that reflects the full picture of a person’s mental health.

What this can mean for you

The presence of more than one condition can make diagnosis and treatment more complex, but it can also help explain why some supports have not been sufficient. When ADHD and a coexisting condition are both recognized, your treatment plan can become more complete, with additional strategies and supports that can provide more complete support for your needs.

“While having more than one condition may pose challenges for consumers and require more intensive diagnosis, treatment, and therapy, people with co-occurring conditions can get effective treatment,” says Husseini K. Manji, MD, an adjunct professor in psychiatry and behavioral sciences at Duke University School of Medicine. “Many university centers have specialized clinics that have more experience with individuals with comorbidities. Then, the treatment recommendations can often be implemented ‘locally.’”

Knowing that co-occurring conditions are common can help you pay attention to symptoms that may not be explained by ADHD alone. It can also help you speak with your healthcare provider about the full range of symptoms or challenges you or your child are experiencing.

Looking for more?

• ADHD and Coexisting Conditions
• Coexisting Conditions in Children
• ADHD and Co-Occurring Medical Conditions
• Conflicting Diagnoses? Take the Time to Get It Right
• The Co-Occurrence of Other Neurodevelopmental Disorders and ADHD