ADHD Comorbidities

What is a comorbid condition?

Comorbid conditions are distinct diagnoses that exist simultaneously with ADHD. They do not go away once the primary condition – in this case, ADHD – is treated. Comorbid conditions exist in parallel with ADHD. Co-existing conditions may interact and make each set of symptoms more severe.

Of course, it is also possible for someone who does not have ADHD to have one or more of these other diagnoses instead of ADHD: so, for example, someone can have anxiety without ADHD, or bipolar without ADHD.

The need to consider other diagnoses occurring instead of or in addition to ADHD is one reason why the assessment of these conditions is such a highly complex area.

Common ADHD comorbidities


Anxiety is the body’s physical response to a threat or perceived threat. It causes a pounding heart, rapid breathing, butterflies in the stomach and a burst of energy as well as mental responses such as excessive fears, worries or obsessive thinking. For more information about anxiety and the different types of anxiety disorders, please click here.


Autism is a complex developmental disorder that can cause social, communication, and behavior challenges. For more information about Autism Spectrum Disorder, please click here. 


Bipolar disorder is characterized by extreme mood swings, abrupt changes in energy levels, and distorted decision making. For more information about Bipolar disorder, please click here. 


While we all feel sad, moody or low from time to time, some people experience these feelings intensely, for long periods of time (weeks, months or even years) and sometimes without any apparent reason. Depression is more than just a low mood – it’s a serious condition that affects your physical and mental health. For more information about depression, please click here. 


Learning disabilities are usually lifelong problems that affect someone’s ability to learn in one or more specific academic areas, such as reading, writing or maths. They are sometimes called learning difficulties.

The most common learning disabilities are:

  • Dyslexia, which causes problems with reading and writing — about 8 in 10 people with a learning disability have dyslexia
  • Dysgraphia, which causes problems with spelling and handwriting
  • Dyscalculia, which causes problems with maths
  • Dysphasia, which causes problems with speaking and understanding others’ speech

For more information about learning disabilities, please click here. 


OCD is a mental health disorder characterized by obsessions (recurring, unwanted thoughts) that lead to compulsions (repetitive behaviors or mental acts that an individual feels compelled to perform to “undo” the obsession). For more information about OCD, please click here. 


Oppositional defiant disorder (ODD) is a childhood behavior disorder defined by a persistent pattern of hostile, vindictive, and defiant behavior toward authority figures. Children with ODD are frequently irritable, argumentative, and disobedient. For more information about Oppositional Defiant Disorder, please click here. 


Tourette syndrome, or TS, is an inherited neurological disorder that causes people to make involuntary and uncontrollable vocal sounds and movements, called ‘tics’. For more information about Tourette’s Syndrome, please click here.