According to a 2019 review, 60–90% of children with attention deficit hyperactivity disorder (ADHD) have at least one comorbid disorder, which may have lifelong effects. Additionally, 80% of adults with ADHD have at least one comorbid mental health condition. Because ADHD presents differently among individuals, it can be challenging to diagnose and treat—especially when it’s compounded by other conditions.
With scientifically backed, digital ADHD assessment tools, providers can leverage objective data to more easily identify ADHD comorbidities. In this article, we will review how common ADHD comorbidities present and affect diagnosis, as well as the tools that assist with clinical decision-making.
Key Takeaways
|
The Impact of Comorbid Disorders on ADHD
For patients with ADHD, comorbid conditions can lead to more severe symptoms and greater challenges in day-to-day life. Along with this, when comorbidities are left unaddressed, they can complicate clinical management and increase healthcare costs.
Effectively treating ADHD depends on providers understanding the impact of any other existing comorbid conditions. Getting to know patients through comprehensive evaluation helps give context to symptoms that may be flagged in ADHD screening.
Common Psychiatric ADHD Comorbidities
Psychiatric conditions are commonly comorbid with ADHD. Some of the most common psychiatric comorbidities in patients with ADHD include:
- Anxiety disorders
- Mood disorders
- Learning disabilities
- Substance use disorders
Neurodevelopmental Comorbidities: ADHD and Autism Spectrum Disorder
ADHD often coincides with neurodevelopmental disorders like autism spectrum disorder (ASD), learning disorders, and tic disorders.
Here are some of the ways co-occurring symptoms can present in patients:
Autism Spectrum Disorder
Autism spectrum disorder (ASD) is a lifelong neurodevelopmental condition that can affect sensory processing, social communication, emotional regulation, and behavior. Like ADHD, it is a type of neurodiversity that has multiple presentations.
Overlapping symptoms of autism and ADHD include challenges with:
- Social skills
- Attention
- Concentration
- Sensory processing
Despite symptom overlap, it is possible to discriminate between symptoms with accurate screening tools. Assessments like the Adult ADHD Self-Report Scale (ASRS) Part A and Autism Spectrum Quotient (AQ) Questionnaire can give clinicians a fuller view of patients’ internalized and externalized symptoms.
Learning Disorders
Learning disorders are a group of conditions that affect a person’s ability to understand, process, or remember information. These disorders can impact a person’s performance in school, work, and daily life. It is estimated that 20-60% of individuals affected with ADHD also experience learning disorders.
Some common types of learning disorders and their challenges include:
- Dyslexia: Reading, spelling, and writing
- Dyscalculia: Math concepts and calculations
- Dysgraphia: Handwriting and fine motor skills
- Auditory processing disorder: Processing and understanding auditory information
- Visual processing disorder: Processing and understanding visual information
Tic Disorders
Tic disorders involve sudden, uncontrollable movements or sounds that can range from mild to disruptive. These disorders are commonly comorbid with ADHD with more than half of children diagnosed with Tourette syndrome also having ADHD.
Tic disorders may improve over time but can also persist and can cause emotional stress as well as disrupt focus, leading to challenges in school, work, and social relationships. Pairing ADHD questionnaires with objective screening tools supports early detection, allowing clinicians to intervene sooner, leaving more time to address the onset of tics before they advance, potentially reducing the severity or frequency of symptoms.
ADHD Screening for Internalizing and Externalizing Comorbid Disorders
ADHD comorbidities can manifest with both outward, observable behaviors and internal emotional distress. Comprehensive ADHD assessments help clinicians uncover a wide range of symptoms, leading to more accurate diagnoses and effective treatment planning.
Here is a look at several common disorders comorbid with ADHD, and how their symptoms can overlap:
ADHD Comorbidities: Internalizing Disorders
Internalizing disorders are disorders that are composed of covert symptoms that may be difficult to observe. For internalizing mood disorders, distress is directed inward, manifesting as sadness, anxiety, low self-worth, or withdrawal. These symptoms are often not clearly visible, making them difficult to detect without structured screening.
Common internalizing disorders include:
- Depressive disorder. Depression is nearly 3 times as common in adults with ADHD, and it is estimated that 44% of ADHD patients will have a depressive episode before the age of 30. Both conditions can affect mood, motivation, and concentration, making it hard to distinguish between them.
- Bipolar disorder. Up to 20% of people with ADHD experience bipolar disorder comorbidity. ADHD and comorbid bipolar disorder share symptoms, making accurate assessment critical for making informed, effective clinical decisons.
- Anxiety disorders. About half of adults with ADHD also have an anxiety disorder, which leads to persistent worry, chronic stress, fatigue, and trouble sleeping. While anxiety and ADHD can co-occur, having ADHD may also cause or exacerbate anxiety.
With ADHD, overlapping traits like restlessness, poor focus, or disorganization can be mistaken for symptoms of other conditions However, persistent or worsening patterns may flag a larger issue. Data about symptom duration, severity, and functional impact is key for distinguishing primary ADHD traits and an internalizing disorder.
Combining objective cognitive assessment tools and screens like the Patient Health Questionnaire (PHQ-9) offers a more robust diagnostic picture. These tools don’t just validate a patient’s internal experience; they also give clinicians the clarity needed to make informed, confident diagnoses.
Accurate identification is also critical for treatment planning. Therapeutic approaches and medications can overlap with some disorders, but some disorders require specific treatments. For example, while stimulant medication is a common treatment for ADHD, it can worsen symptoms of bipolar disorder.
Recognizing co-occurring conditions early helps prevent contraindications and supports more personalized, effective care.
ADHD Comorbidities: Externalizing Disorders
Externalizing disorders, in contrast, are highly observable and are characterized by disruptive, hyperactive, and aggressive behaviors. In children and adolescents with ADHD, overlapping symptoms such as impulsivity and emotional dysregulation can lead to missed diagnoses and inadequate treatment.
The two primary externalizing disorders associated with ADHD are:
- Conduct disorder (CD) is characterized by persistent aggression toward others and a pattern of rule-breaking behavior.
- Oppositional defiant disorder (ODD) is marked by ongoing defiance and anger-driven disobedience.
Behaviors like impulsivity and emotional reactivity may stem from ADHD, but—the same as with internalizing disorders—when symptoms become more intense or impair daily functioning, comorbidity should be considered.
Diagnosing CD and ODD in children with ADHD involves a comprehensive evaluation, including:
- Clinical interviews
- Behavioral observations
- Questionnaires for parents, teachers, caregivers, and the patient
- Cognitive assessments
One challenge in diagnosing externalizing disorders lies in systemic disparities. On average, Black children are 69% less likely to receive an ADHD diagnosis and are more likely to be diagnosed with CD or ODD instead, for example. These patterns reflect the impact of unconscious racial bias on clinical judgment.
Gathering objective data is one way to counteract bias. Digital cognitive tasks like those from Creyos objectively measure short-term memory, reasoning, concentration, and verbal ability, providing a clearer picture of a patient’s neurocognitive profile.
These tools, combined with a patient-centered approach to understanding patients’ lives, can support more accurate, equitable diagnoses.
ADHD Questionnaires for Diagnosing ADHD and Comorbid Conditions
Confidently diagnosing ADHD and comorbid conditions can be made easier by relying on a combination of subjective and objective data. Where objective measurements provide key neurocognitive data, subjective behavioral health questionnaires give context about how symptoms manifest.
In a time when patients may seek a diagnosis due to information they’ve seen about ADHD on social media, scientifically trusted questionnaires give data that matches DSM-5 criteria. This can help differentiate an ADHD comorbidity from ADHD itself.
Common questionnaires for diagnosing ADHD include:
- Adult ADHD Self-Report Scale (ASRS Part A)
- Conner’s Rating Scale for ADHD
- Strengths and Weaknesses of Attention-Deficit/Hyperactivity Symptoms and Normal Behavior Scale (SWAN)
- Vanderbilt ADHD Diagnostic Rating Scale (VADRS)
If some of these symptoms are resonating with patients, but more information is needed, this is an opportunity for closer investigation about comorbidities. Additional questionnaires can help distinguish separate or overlapping conditions, and objective cognitive testing can measure attention deficits associated with ADHD or other cognitive symptoms of a comorbid condition. Together, these tools help clinicians build a treatment plan that best suits their needs.
How Creyos Helps With ADHD Assessment
With more patients seeking ADHD diagnoses, there’s increased pressure on healthcare providers to offer clarity and accuracy around ADHD diagnosis and to disentangle comorbidities.
With the Creyos Health ADHD Cognitive Assessment, providers can measure patients’ subjective and objective symptoms, opening an appropriate path for treatment or referrals. It can be completed in under 20 minutes either in-clinic or remotely and produces an easy-to-read report for providers and patients alike.
Some features of this protocol include:
- Objective measurement of 14 cognitive markers associated with ADHD
- Age-appropriate adjustments for adults and children
- A combination of cognitive tasks and trusted behavioral health questionnaires
- Re-testing capabilities to track the efficacy of medication and other treatments
- Integration with patients’ electronic health records (EHRs).
With our scientifically validated tools, you can use objective data to identify or rule out ADHD comorbidities, allowing for better quality of care for patients.
Contact us today to learn more about how our ADHD assessments can support your clinical practice.
Getting to the Bottom of Diagnosis
Diagnosing ADHD is essential for setting up both child and adult patients for success in their daily lives. By recognizing and treating ADHD comorbidities, patients can receive the whole-person care they need to have their needs met.
Want to simplify the process of getting the full picture? Reach out to us for a demo of the ADHD Clinical Protocol and Report.
Reviewed by Sydni Paleczny, Staff Scientist
Sydni earned her MSc in Neurosciences at Western University under Dr. Adrian Owen. Her research explores neuropsychological outcomes after cardiac surgery, with interests in cognitive neuroscience, critical care, and brain health. At Creyos, she supports scientific validity, health technology, and ongoing research.