PANDAS: A link between strep throat and OCD
PANDAS: A link between strep throat and OCD
Can an ordinary streptococcal infection (strep throat) lead to obsessive-compulsive disorder (OCD)? In a small subgroup of children, a seemingly normal bacterial strep infection can turn into a severe neuropsychiatric disorder. The disorder affecting this group is known as PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections), and was identified by Dr. Susan Swedo just twelve years ago (1). Though research on PANDAS is still very much a work in progress, it has already generated excitement that this disorder may lead to answers about the cause and nature of OCD (2). Similarities and differences between PANDAS patients and the majority of OCD patients, experimental treatments for PANDAS infections, and comorbidity of PANDAS with a variety of other psychiatric and neurological disorders are slowly leading to an understanding of exactly what OCD does to the brain (3).
It is not the streptococci themselves that cause OCD symptoms. Rather, strep infections seem to cause the body's immune system to build up antibodies that, for an unknown reason, begin to attack the basal ganglia in rare cases (1). The link between streptococcal infections and neurological disorders has been known about for half of a century. Rheumatic fever was identified in the 1950s as being an autoimmune disorder correlated with strep; Sydenham chorea, a disorder of the central nervous system involving hyperactivity, loss of motor control, and occasionally psychosis, was recognized as another strep-linked disorder that could be a symptom of Rheumatic fever or could stand on its own. PANDAS seems to be a milder form of Sydenham chorea (4).
Dr. Swedo observed, tested, and interviewed fifty children with a sudden onset of OCD or tic disorders who had recently (within the past several months) been diagnosed with a group A beta-hemolytic streptococcal (GABHS) infection. These children tested negative for Sydenham chorea. Swedo discovered that the children had episodic patterns of OCD and tic symptoms. She tested the presence of antistreptococcal antibodies in their blood and found that symptom exacerbations were twice as likely to occur with the presence of antistreptococcal antibodies (1). Brain imaging studies found that the caudate nucleus, frequently linked with OCD, became inflamed in PANDAS patients when antibody presence was high (2).
OCD symptoms are generally very similar between children with PANDAS and other OCD patients (5). However, the onset of symptoms can be quite different. While OCD is usually first identified in adolescence, PANDAS patients are always prepubescent. This is likely to be because of the rarity of GABHS infections in teens and adults. Also, though OCD usually manifests itself gradually, in PANDAS patients it can set in overnight. Swedo and colleagues report frequently seeing children whose parents could recall the day their child became obsessive-compulsive (2). Though it is not known why, PANDAS patients overwhelmingly obsess about urination, which is not an especially dominant obsession in other OCD cases (5). The episodic pattern of symptoms is unique to PANDAS patients. While other OCD patients can go through periods where symptoms are slightly more or less exacerbated, PANDAS patients often experience complete disappearance of symptoms between episodes (1). It is unknown whether a genetic marker on B cells of the immune system known as D8/17 is specific to PANDAS patients, or common in all OCD patients (6). The structure and function of this marker is currently being identified, and may provide some clues about the heredity of PANDAS or OCD in general (2).
Thus far, studies in which penicillin was given to PANDAS infected children as a preventative measure against strep and OCD have been inconclusive (3). However, many PANDAS patients have shown significant reduction of OCD symptoms when given plasmaphoresis, a type of plasma transfusion, to remove the antibodies (2). Current studies are further investigating prophylactic antibiotics, plasma exchange, and steroids as possible treatments to go along with SSRIs in treating both PANDAS and ordinary OCD.
As in most cases of OCD, other neuropsychiatric disorders are often present in PANDAS patients. Swedo and colleagues found that 40% of PANDAS patients suffered from ADHD, 42% from affective disorders, and 32% from anxiety disorders (1). There are several points of interest in discussing the comorbidity of these illnesses with PANDAS. It was found that non-OCD psychiatric symptoms in most cases followed the same cycles as OCD symptoms, and set in suddenly when antibody levels were high (1). This brings up the question of whether any additional psychiatric disorders can be triggered by strep throat or other bacterial infections. Though there is no evidence to date linking post-strep autoimmune dysfunction with any illnesses other than tic disorders, OCD, and possibly late-onset ADHD, researchers are looking into possible ties with disorders like autism, anorexia, and depression (2). The comorbidity statistics also suggest that particular areas of the brain which we know are involved in other psychiatric disorders are attacked by the post-strep antibodies, and could help lead to identifying the exact cells or proteins that are targeted. Interestingly, the putamen and globus pallidus, neighbors of the caudate nucleus, are linked to tic disorders and hyperactivity (2). This could explain the frequency of occurrence of these symptoms alongside OCD in PANDAS.
The frequency of PANDAS in the general population is unknown, but it is definitely a rare disorder. By contrast, OCD is present in one to two percent of the population (7). This may make PANDAS research appear useless in relation to research on "normal" OCD. On the contrary, the small size of the subgroup of PANDAS sufferers and the link to a disease as widely studied as strep throat could provide the key to discovering the cause of OCD and identifying exactly what genes and brain structures are involved (2). For example, if the nature of the antibody attack on the basal ganglia in PANDAS were identified, researchers could possibly target similar degradation in the basal ganglia of other OCD patients and potentially begin to look at ways to prevent this degradation. Also, research and public knowledge about PANDAS might make more people aware of the medical aspects and biological causes of mental illnesses. Perhaps this would lessen societal discrimination against the mentally ill and lead more people to understand why pharmaceuticals are often helpful or necessary in treating mental illnesses (7).
There is strong evidence of a link between streptococcal infections and obsessive-compulsive disorder in some children. Though it is not known exactly how the immune system turns against itself and causes behavioral symptoms, there is hope within the scientific community that answering questions about PANDAS will in turn lead to answers about OCD and mental illness in general. This disorder provides evidence for medical models of psychiatric illnesses, and for the idea that the brain = behavior. It is amazing and frightening that an illness that seems like a mere nuisance can lead to a severe behavioral change almost overnight. However, research and possible treatments appear promising, and this tiny disorder may contribute more to the body of neuropsychiatric knowledge than any other illness in the past.
1) American Journal of Psychiatry Website, First Susan Swedo article about PANDAS, defines symptoms and criteria
2) The Scientist Website , Harvey Black article discussing research and several points of view on PANDAS
3) Science Direct Website , Pilot study on use of prophylactic penicillin in treating PANDAS
4) Medscape Website, Register for Medscape, then go to Richard Barthel article "Pandas in Children - Current Approaches", overview of knowledge on PANDAS
5) JAMA Website , Joan Stephenson article discussing antibiotic treatment
6) Psychiatric News Website , Article discussing biological marker associated with OCD
7) University of Florida News , Current research being done on PANDAS and OCD
01/18/2006, from a Reader on the Web
MY PATIENT AND I THANK YOU FOR A VERY HELPFUL PAPER. DR. VTS
My daughter Sacha, aged 6, developed OCD related symptons around the age of 4, two weeks after a strep throat infection. The symptons were brief and melted away over a period of 4 weeks. She had a second strep throat approx. 3 months ago which, unfortunately, was not attended to quickly enough, developing a rash over her body. No evidence of Scarlet Fever. Check for Rheumatic Fever was requested as she complained of sore knees, (negative). Since then she had three more suspected strep throats back to back (no cultures taken). She now has suddenly developed severe symptons of Tourettes. Awaiting diagnosis from specialists ... Belinda Allen, 26 July 2006
My son's doctor just told me about this correlation between strep and OCD today. We have started on an antibiotic to see if it relieves some of the symptoms. This was a great, easy to understand article. Thank you ... Robin Maupin, 25 October 2006
I read your article on PANDAS, after researching OCD. I was researching OCD because I beleive I have OCD. Even though I have not been clinically diagnosed, I am 100% sure i do. I have every symptom that is listed. Anyway, I had read a small paragraph that strep throat at a young age could lead to OCD. I was repeatedly infected with strep throat, when I was younger. Almost every year consecutively for a long time. This all seems to make sense now. I beleive that I got OCD from strep throat. One reason is because of getting strep throat every year, and now I [know] I have OCD. But another is because since I was younger I would have different episodes of having to say something over and over again, to feel right. And this wasnt present until I was say, 8-10 years of age. And everytime, I would have an episode, then be free of symptoms for a stretch of time, and feel normal. Then something else would takeover. Now I need this constant reassurance on one paticular issue. The funny thing is, is that I was free of symptoms for 6 months, and it has resurfaced in the past 3. There has been speculation that many people with OCD are unaccounted for clinically, I believe this to be true with PANDAS as well. While it is rare that the brain would have an autoimmune response because of this infection, I dont think it is too unlikely, especially after repeated exposure. Most people with OCD keep it to them themselves. And I think its because they know its obsurd, their actions and thoughts I mean. But they just cant help it. To feel right, they must have this reassurance with things. To constantly go over something, no matter how many other times they have thought about it, and have settled it in their mind. And even though people with OCD know that what they are feeling is because of a disorder, it doesnt matter. It doesnt help. Right now I take 5 htp supplements, I have read many studies that these help OCD and other related mental illnesses, by increasing the amount of serotonin. Also psilocybin has been succesfully used to treat OCD, which also by a twist of fate has to do with serotonin, specifically 5ht b and c, I beleive [could be wrong]. Anyway, thank you for your time. Your articles are greatly appreciated ... Conor, 11 April 2007
I am interested in learning more about P.A.N.D.A.S. (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections; specifically, whether there are any reports of this syndrome progressing into adulthood, as well as any current treatment recommendations and any specific bio markers. As far as I understand, the link is made presumptively based on history combined with the presence of immunologic markers for strep (which are very common). My questions are: Are you aware of any tests that are highly specific for PANDAS and if so, what are they? Are you aware of any reporta of adult cases (unreckognized in childhood, but diagnosed in adulthood as ongoing/chronic PANDAS)? What are the current treatment recommendations for this condition in adults? Thank you very much for any help that you are able to offer ... Bryan Conkling, 15 November 2007
My 17 year old son seemed to develop OCD out of the blue and it is now progressed very rapidly. He is currently awaiting bloodwork and evaluation for PANDAS. This paper was very helpful and informative. Thank you ... Lisa, 29 November 2007