An image of a brain planted with different plants, and a therapist in the middle, illustrating an article about comorbidity on

Print Friendly, PDF & Email

Click below to listen to this article:


Comorbidity is a term that refers to the coexistence of two or more health conditions in a person, regardless of whether they are related or independent of each other (Healthline, 2022). Comorbidities can have various causes, such as shared risk factors, complications of one condition, or chance occurrence (Healthline, 2022). Comorbidities can affect the diagnosis, treatment, and prevention of diseases, as well as the quality of life and prognosis of patients (Verywell Health, 2022). Some examples of common comorbidities are diabetes and hypertension, arthritis and depression, and stroke and heart attack (Healthline, 2022; Verywell Health, 2022).

Statistics of comorbidity

Dyslexia and attention deficit hyperactivity disorder (ADHD) are two common childhood conditions that often co-occur and affect learning and academic achievement. According to Darweesh et al. (2020), dyslexia shows high comorbidity with ADHD, oppositional defiant disorder (ODD), and conduct disorder (CD), affecting dyslexic boys more than girls. Dyslexic children also show more internalizing and externalizing behaviours than non-dyslexic children. The authors suggest that students with dyslexia should be evaluated for other psychiatric comorbidity and referred for appropriate management.

Similarly, Chase (2023) notes that ADHD and dyslexia share many features, such as difficulties with attention, reading comprehension, and working memory, and that both conditions are highly heritable. The author warns that evaluators may confuse ADHD and dyslexia or miss the presence of a comorbid condition, and recommends a thorough assessment that considers each symptom cluster. The prevalence of dyslexia varies across countries, but it is estimated at 4% of school-age children in the USA (Chase, 2023) and 2.6% of primary school children in Egypt (Darweesh et al., 2020). The prevalence of ADHD in adults in the UK is estimated at 3% to 4%, with a male-to-female ratio of approximately 3:1 (NICE, n.d.).


Chase, C. (2023). Dyslexia evaluation with ADHD: Comorbid considerations and complications. ADDitude.

Sign up for our Newsletter!
We will send you regular updates regarding new articles, as well as hints and tips regarding self-transcendence. We aim to limit this to once per month, though some months we will have additional special editions covering significant articles worthy of being the sole focus of a newsletter. There will be no sales spam or selling your address to third parties.

Darweesh, A. M., Elserogy, Y. M., Khalifa, H., Gabra, R. H., & El-Ghafour, M. A. (2020). Psychiatric comorbidity among children and adolescents with dyslexia. Middle East Current Psychiatry, 27(28).

Healthline. (2022). Comorbidity: Definition, Types, Risk Factors, Treatment & More. Retrieved from

NICE. (n.d.). Attention deficit hyperactivity disorder: How common is it?

Verywell Health. (2022). Comorbidities: meaning and Common Examples. Retrieved from

New article alerts!
We will notify you of new articles as soon as they are published. There will be no sales spam or selling your address to third parties.
Print Friendly, PDF & Email


Leave a Reply

Avatar placeholder

Your email address will not be published. Required fields are marked *

Skip to content