Could a Strep Throat Increase Risk of OCD? Interview with:
Sonja Orlovska MD, PhD student

Mental Health Centre Copenhagen
Denmark What is the background for this study?

Response: This Danish register-based study is the largest study so far investigating the hypothesis PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections) which describes a possible link between streptococcal throat infection and the subsequent development of OCD and tic disorders in children. PANDAS is in thread with research in mental health in recent years, suggesting that infections and immune activation might increase the risk of mental disorders. What are the main findings?

Response: Out of the 1,1 million individuals <18 years of age born in the study period, we found that the 349,982 individuals tested positive for a streptococcal throat infection by their GP had an increased risk of mental disorders by 18% and the risk of specifically OCD and tic disorders was increased with respectively 51% and 35%, compared to individuals who had never been tested. This seems to confirm PANDAS which speaks in favor of a specific link between strep throat and the development of OCD and tic disorders. However, we also found that non-streptococcal throat infection increased the risk of mental disorders, even though the risk of OCD and all mental disorders was larger after a strep throat. The study was performed at the Mental Health Centre Copenhagen together with Senior researcher Michael Eriksen Benros. What should readers take away from your report?

Response: Our results indicate that the brain might be affected by the immunological activation caused by a streptococcal infection possibly due to streptococcal antibodies cross-reacting with brain tissue causing psychiatric symptoms which is the theory of PANDAS. However, it seems as if the immunological response caused by other types of throat infections might also have a damaging effect in some individuals. Nevertheless, it cannot be ruled out that the results to some extent might be driven by a medical care-seeking behavior in some parents bringing their child to the GP more often in spite of only few symptoms of throat infection leading to testing for strep throat and also more frequent examination and diagnosis by a psychiatrist. What recommendations do you have for future research as a result of this study?

Response: Even though our study supports some elements of the PANDAS hypothesis, more research is needed to fully confirm PANDAS. The research field would benefit from larger clinical studies following children with PANDAS over a longer period of time with frequent follow-ups in order to establish if streptococcal throat infections cause and worsen neuropsychiatric symptoms of OCD and tic disorders. Thank you for your contribution to the community.


Orlovska S, Vestergaard CH, Bech BH, Nordentoft M, Vestergaard M, Benros ME. Association of Streptococcal Throat Infection With Mental DisordersTesting Key Aspects of the PANDAS Hypothesis in a Nationwide Study. JAMA Psychiatry. Published online May 24, 2017. doi:10.1001/jamapsychiatry.2017.0995

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.

More Medical Research Interviews on

[wysija_form id=”5″]

Last Updated on May 25, 2017 by Marie Benz MD FAAD