Most people with ADHD have a co-occurring condition. It’s important to work with your doctor to ensure you’re managing any other conditions to ensure they don’t worsen your ADHD symptoms.

Nearly 4 in 5 children and teens with ADHD have a co-occurring health condition, according to 2024 research. Adults with ADHD are also much more likely to have a co-occurring mental health disorder than adults without ADHD.

Also known as comorbidities, co-occurring conditions can complicate the diagnosis and treatment of ADHD. They can also worsen ADHD symptoms, making managing ADHD more challenging.

Here are some conditions that may co-occur with ADHD, how to recognize their symptoms, and how to seek help.

A 2024 study found that behavior or conduct problems were the most common disorders among children with ADHD. Conduct disorders are more common in boys with ADHD.

Among these, the most common may be oppositional defiant disorder (ODD), which some experts think might affect 50% to 60% of children with ADHD. ODD causes defiant behavior and attitudes toward parents and other authority figures, as well as frequent irritation, anger, and vindictiveness.

ODD can be a precursor to conduct disorder, which is more severe and has broader effects. People with conduct disorder typically show antisocial and aggressive behaviors.

Research suggests that children with ADHD and comorbid ODD or conduct disorder may have heightened symptoms and more difficulty at school, in social situations, and with the law. Experts recommend early screening for ODD and conduct disorder.

More than 1 in 3 children with ADHD have a learning disorder like dyslexia, which affects reading and writing skills, or dyscalculia, which affects math learning. You might have difficulty with memory, reasoning, or learning new concepts.

It can sometimes be tricky to determine whether learning issues are due to ADHD, a learning disorder, or both. A qualified education or mental health specialist can help you distinguish between the conditions and get you the help you need.

If you or your child has both ADHD and a learning disorder like dyslexia, research suggests that treating ADHD and utilizing learning interventions may lead to the best outcomes. You may also benefit from accommodations to help at school.

ADHD and autism spectrum disorder (ASD) can appear very similarly, which can make diagnosis challenging. But it’s possible to have both. Studies show that 14.4% of children with ADHD also have ASD, while 40.2% of autistic children will have ADHD in their lifetime.

Children with both ADHD and ASD may exhibit more severe inattention or hyperactivity than those with only one condition. Early symptoms to look for include:

  • not waiting their turn
  • intruding
  • talking excessively
  • excessive fidgeting or squirming

Children with ADHD often receive an ASD diagnosis later than autistic children without ADHD. It’s important to talk with your child’s doctor if you notice symptoms to ensure early diagnosis and treatment if necessary.

A 2021 systematic review found that about 1 in 10 children and adolescents with ADHD develop bipolar disorder. A large 2018 study in Denmark also found that people over age 16 were 11 times more likely to develop bipolar disorder if they had ADHD.

Bipolar disorder causes extreme shifts in mood through alternating and extended episodes of mania and depression. Compared to people without ADHD, those with ADHD who develop bipolar disorder often experience:

Early recognition leads to more effective treatment, so it’s essential to talk with a mental health professional if you notice symptoms of bipolar disorder in you or your child.

About 2 in 5 children with ADHD have problems with anxiety. The same goes for more than half of adults, according to the Anxiety & Depression Association of America. Symptoms of anxiety may include:

  • persistent worry or nervousness
  • feelings of panic, including rapid breathing or heart rate
  • headaches and stomachaches
  • irritability

It’s unclear why so many people with ADHD develop anxiety disorders, but there may be a genetic link. Females with ADHD are more likely to report anxiety.

The effects of anxiety on people with ADHD may differ depending on age, according to a 2019 study. In teens, anxiety may cause problems with working memory. In adults, it may lead to sleep problems.

Research also suggests that people who have ADHD and anxiety may be less likely to benefit from behavioral therapy and may need medication. Talk with your doctor if you experience symptoms of anxiety along with your ADHD.

About 1 in 5 children with ADHD also has depression. Studies in adults have found that between 8.6% to 55% of adults with ADHD have a depressive disorder.

Like with anxiety, ADHD and depression appear to have a genetic link. According to the Attention Deficit Disorder Association, ADHD can also contribute to depression by:

A doctor may prescribe medications like antidepressants along with ADHD medications to help treat depressive symptoms that accompany ADHD. Cognitive behavioral therapy can also help treat both conditions.

Tic disorders cause repetitive, sudden, and involuntary movements or vocalizations. They might appear as:

Tic disorders may be more common in children with ADHD due to genetic and environmental risk factors. Scientists have also observed similarities in brain circuitry between people with ADHD and those with tic disorders.

One of the most notable tic disorders is Tourette syndrome, which has a strong link to ADHD. While only 1% of children with ADHD have Tourette syndrome, more than half of children with Tourette syndrome have ADHD, according to the Centers for Disease Control and Prevention.

If you notice tics in you or your child, a doctor can perform an examination and provide a diagnosis. They’ll also carefully consider treatment options, as some ADHD medications may worsen tics in rare situations.

According to a 2019 review, adults with ADHD are about 70% more likely to have obesity than adults without ADHD, while children with ADHD have a 40% higher chance than their peers. While there may be a genetic link, ADHD symptoms can contribute to obesity by causing unusual eating habits.

Research also suggests that managing ADHD with medication can help reduce the risk of obesity. The role of ADHD medication in weight management is still unclear, but stimulants (the most common ADHD medications) often suppress appetite and are linked to weight loss.

Similar to obesity, ADHD may cause changes in eating habits that could lead to eating disorders. Recent research suggests that as many as 1 in 5 children or adolescents with ADHD may develop an eating disorder. This may be related to the role dopamine (the “reward hormone”) plays in both conditions.

The most common eating disorders in children and teens with ADHD are binge eating disorder, which involves periods of excessive eating, and bulimia nervosa, which involves purging behaviors like forced vomiting or excessive exercise.

Treating an eating disorder often involves a multidisciplinary team of doctors and nutritionists. ADHD symptoms can complicate treatment for eating disorders, especially with inattentive-type ADHD. Treatment typically includes both medication and behavioral therapy.

Experts previously thought of the impulsivity of ADHD and compulsivity of obsessive-compulsive disorder (OCD) as existing at distinct points on a spectrum. However, new research suggests that there may be a link between the two conditions. The brains of people with ADHD and OCD show similar changes.

It’s also possible to have both ADHD and OCD. According to 2020 research, OCD may be more common in people with hyperactive-impulsive type ADHD. Symptoms most common in adults with both conditions included obsessions with symmetry and hoarding.

Treatment for OCD may involve therapy and medication. A 2021 case study of a 33-year-old with both conditions found that extended-release methylphenidate (Ritalin), a common ADHD medication, also helped reduce some OCD symptoms. More research is needed.

Studies estimate that somewhere between 2.3% and 41.2% of people with ADHD may have substance use disorder, a condition where you continue to use drugs or alcohol despite the negative consequences.

Like many comorbidities, there may be a genetic link between ADHD and substance use disorders, like:

It’s important to note that while medical professionals express concern over the risk of misuse of stimulants among adolescents with ADHD, there’s no evidence that stimulants lead to substance use disorder. In fact, research shows that treatment with stimulants can help reduce the risk of substance use in people with ADHD.

It’s common for people with ADHD to have another condition. Some of the most common include mental health conditions, such as mood disorders like anxiety, depression, or bipolar disorder. Other comorbidities include autism, tic disorders, and obesity.

If you or your child has ADHD, it’s important to be aware of the risk factors and symptoms of possible comorbidities. Early detection can help ensure you manage both conditions effectively.