What’s known about comorbid conditions in ADHD?

The European collaborative study CoCA (Comorbid conditions of ADHD) aims to identify and treat major comorbid conditions in ADHD. It is mainly focused on mood and anxiety disorders, substance use and obesity.

However, in addition to these well documented co-occurring problems , other conditions have also been reported to be associated with ADHD. For clinicians and researchers alike, it’s important to be aware of such connections.

In a recent systematic review, Instanes and coworkers attempted to identify and evaluate the scientific evidence published during the past 20 years, connecting adult ADHD with any somatic condition.

Starting from >4000 articles, the authors identified 126 studies that were subjected to further scrutiny. Although many potentially important comorbid conditions were reported, the authors concluded that most of the studies were “small and of modest quality”.

Importantly, many studies suffered from methodological shortcomings, such as using “convenience samples”, where ADHD cases and controls were not adequately matched. Other studies used non-standard diagnostic criteria or protocols, making it difficult to compare date across sites.

Given the importance of this problem, more data is obviously needed. More care should also be given to the design of such studies. In particular, Instanes et al. recommend the use of population based registry studies and common diagnostic protocols to estimate the rates of comorbidity.

CoCA aims to make a major contribution to our understanding of ADHD comorbidities, not only by generating more data, but also by providing more reliable and clinically relevant information.


Instanes JT, Klungsøyr K, Halmøy A, Fasmer OB, Haavik J. Adult ADHD and Comorbid Somatic Disease: A Systematic Literature Review. J Atten Disord. 2016 Sep 22. pii: 1087054716669589. PMID: 27664125

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s