ADHD and Other Conditions

ADHD Co-exists with other Conditions

Attention Deficit/Hyperactivity Disorder (ADHD) is a highly comorbid condition, meaning it often co-occurs with other conditions and mental health problems.

87% of children with ADHD have at least one comorbid condition, and 67% of children with ADHD have at least 2 comorbidities.
77% of adults with ADHD have at least one comorbid condition. Comorbidity contributes to the failure to diagnose ADHD in adults.

Common Co-existing Conditions

Learning Disabilities (LDs) commonly co-occur in 45% of children with ADHD.
Developmental Coordination Disorder (DCD) co-occurs in approximately 50% of children with ADHD.
Oppositional Defiant Disorder (ODD) co-occurs with ADHD in approximately 50% of children with the Combined Presentation, and 25% of children with the Predominately Inattentive Presentation.
Conduct Disorder (CD) co-occurs in approximately 25% of adolescents with the Combined Presentation, depending on age and setting.
-Most children and adolescents with Disruptive Mood Dysregulation Disorder (DMDD) have symptoms that also meet criteria for ADHD, while a lesser percentage of children and adolescents with ADHD have symptoms that also meet criteria for DMDD.
Anxiety disorders occur in approximately 25% of individuals with ADHD and mood disorders in approximately 20% of individuals with ADHD, which is more often than in the general population.
Other disorders that may co-occur with ADHD include Obsessive-Compulsive Disorder (OCD), Tic Disorders (including Tourette’s syndrome), and Autism Spectrum Disorder (ASD).

Anxiety and Depression

It is very common for individuals with ADHD to develop secondary anxiety and depression due to their lifelong difficulties regulating their behaviour, which impacts their self-confidence

Emotional and Behavioural Difficulties

Difficulty with emotional regulation is a central feature of children with ADHD. Deficits in executive functions make it much more difficult for individuals with ADHD to control their emotions and maintain appropriate self-regulation. Essentially, the person is reacting before he/she has a chance to hear all of the information presented, think through his/her choices, and develop alternate plans for behavior. This will have an impact on academic or work tasks, following rules, and managing social situations.

Behavioural impulsivity takes away from his/her ability to think about how to initiate tasks and carry out multi-step instructions, and will make task/goal-directed persistence and flexibility in managing tasks more difficult.

While not the cause of aggressive behaviours, it is likely that ADHD makes an individual vulnerable for coping with frustration through emotionally impulsive behaviours rather than calm problem solving.

ADHD & Learning Disabilities

Up to 45% or more of individuals with ADHD will also have a Learning Disability
ADHD is not a Learning Disability. Each is a distinctively neurologically based disorder. Each is recognized and diagnosed differently and treated in a different way.

Article: The Relationship Between ADHD and Learning Disabilities. 

Oppositional Defiant Disorder (ODD)

Untreated ADHD can often evolve into ODD and more serious behavioural problems. Children and adolescents with untreated or not adequately treated ADHD often misbehave, not because they are intentionally oppositional, but because of their difficulty remembering rules and inhibiting their responses. They may develop aversion to school or mentally-demanding tasks due to difficulty in sustaining mental effort, forgetting instructions, and impulsivity.


LEARN MORE about ADHD and related challenges or co-existing conditions.


Article: Half of All Kids with ADHD Have a Learning Disability or Related Condition. Article by Larry Silver, MD. Published in ADDitude.