Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS) is a mental illness with a sudden onset affecting young children. It presents with behaviour typical of obsessive-compulsive disorder (OCD), as well as separation anxiety and mood swings.

PANDAS has been a controversial diagnosis, not least because many of the symptoms place it well within the reach of the autism spectrum disorders (ASD) umbrella. A quick browse of online autism support forums reveals many a discussion on the subject of PANDAS among parents of autistic children or those seeking answers for sudden changes in their child's behaviour. One website estimates that "at least 40%" of children diagnosed with an ASD have PANDAS.

In the medical profession however, PANDAS is most often associated with and compared to child-onset OCD. Some doctors insist there is no such thing as PANDAS and that Streptococcal infections and the onset of neuropsychiatricsymptoms are coincidental and affected children simply have traditional child-onset OCD. Others however (most notably DAN! doctors) believe that the Strep infection triggers the production of antibodies, but instead of only attacking the bacterium, the antibodies also cross the blood-brain barrier and attack the Basal Ganglia. This causes swelling in the caudate, putamen, and globus pallidus regions of the brain and causes the PANDAS symptoms. Of course most children encounter Strep infections at some time but not all develop PANDAS. The reasons for some children succumbing to the neuropsychiatric disorder could be the result of genetic or environmental factors, or both.

Since proponents of PANDAS see it as an autoimmune condition with autoantibodies attacking the brain, they fear it could lead to the development of other autoimmune diseases if the child is left untreated. Treatment would typically involve common antibiotics if the strep infection is identified as the cause of the OCD/ASD-type symptoms early.

After that little bit of background I'll get to the point of this blog post, which is to let you know about a recent study which suggests something - an infection, immune-system problem or environmental exposure - can indeed trigger a stunningly fast onset of OCD.

The research, led by scientists at the US National Institutes of Health (NIH), broadens the definition to describe sudden-onset OCD in children no matter what the cause. The authors go on to suggest calling the broader condition PANS (Pediatric Acute-onset Neuropsychiatric Syndrome). While PANS is a new clinical entity and much more research is needed, the name has quickly been picked up by online support groups for both child-onset OCD and autism. The study and future work that builds on it should lead to faster, more accurate diagnosis of children with sudden behavioural changes and the administration of appropriate treatment - including antibiotics where infectious cause is suspected.

"While waiting for the results of those research investigations, clinicians are encouraged to consider PANS when children present with acute-onset of obsessive-compulsive symptoms, separation anxiety or emotional lability," the authors wrote.

The research paper can be read here.