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  • Writer's pictureRosalie Greenberg, MD

Tick-borne Disorders and Mental Illness in Youth: An Underrecognized Connection

Part 2- Pediatric Mood Disorders and Tick-borne Illness

In my previous blog I discussed the overlap of symptoms shared by Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS), Pediatric Acute-onset Neuropsychiatric Syndrome (PANS) and Pediatric Bipolar Disorder (PBD). PANDAS occurs following a Group A Strep infection and is a category under the larger grouping of PANS. In most cases the cause of PANS is unknown but potential triggers include infections, metabolic disturbances and other causes of inflammatory reactions. In the majority of cases the cause bipolar disorder is also uncertain, but it is probably a mixture of genetics, the environment (including exposure to certain infections) and immune system dysfunction.

A few infectious agents have been accepted as being directly associated with bipolar disorder symptoms. Two of these are 1. the parasite Toxoplasmosis Gondii which causes toxoplasmosis, and 2. the spirochetal (corkscrew shaped) bacteria, Treponema Pallidum which causes syphilis. Of note, both syphilis and Lyme disease (caused by Borrelia burgdorferi), are caused by a spirochete shaped bacteria and they share a variety of other commonalities that will be discussed in greater depth in a later post It is important to note that the Borrelia bacteria has more DNA and is much more complex in composition and function. Individuals who experience late stage, or tertiary, syphilis can exhibit mania-like behavior, which is also be seen at times in those with neurologic Lyme disease.

Because of the similarities I observed between PANDAS/PANS and PBD, I started to check some of my PBD patients for evidence of infection. One was P, an 11-year-old, who came to see me following four psychiatric hospitalizations over the course of one year, because of difficulty with mood shifts, oppositional behavior and verbal and physical aggressive outbursts. He was diagnosed as having PBD, attention-deficit hyperactivity disorder (ADHD) - combined type and oppositional defiant disorder. His difficulties had only mildly improved when I first saw him, despite multiple psychiatric medication trials. His family history was positive for psychiatric illness, notably bipolar disorder in at least three generations. Alcoholism was present in both maternal and paternal relatives. Additionally, there were a variety of autoimmune disorders in relatives on both sides of the family tree. After eight months of medication treatment as an outpatient, he suddenly once again became highly agitated, argumentative and threatening. It was clear that he could not continue to live at home unless his behavior drastically changed. Despite his having been fairly healthy, with no known medical history of a Streptococcal infection, I decided to check for evidence of PANDAS or PANS. To my surprise his strep titers were quite high and he was subsequently diagnosed with PANDAS. A few months of treatment with antibiotics eventually resulted in a dramatic change. His mood was happier and more even; he was much less oppositional, more affectionate and he even became a much more diligent student. Over time, his negative behavior would return and escalate on occasion if he was exposed to an ill peer or family member, but he usually responded quickly with an antibiotic change. He was on a low dose antibiotic prophylactically to protect against recurrent streptococcal infection. This is a protective approach similar to what occurs in those with rheumatic heart disease.

When P was in the 8th grade, he had a severe angry depressive episode. By this time I had become familiar with tick-borne disorders and their potential neuropsychiatric effects. On specialized blood testing he was positive for the bacteria Bartonella henselae. Once again proper antibiotic treatment resulted in a significant lessening of his psychiatric symptoms. It is important to note that he also needed an antipsychotic and anticonvulsant for mood maintenance whether or not he was taking antibiotics.

Given the observation that P’s mood and behavior dramatically changed once his infections were identified and properly treated, I decided to screen many of my new patients for evidence of infection. To my surprise I found evidence of infections in the majority of those newer patients who underwent blood testing during psychiatric evaluation.

I am known as being an expert in pediatric bipolar disorder, having written Bipolar Kids: Helping your child find calm in the mood storm, as well as having lectured to the public and professionals and written a variety of articles for both groups. It’s important to keep in mind that my practice is somewhat atypical in that it experiences what is called “a referral bias,” with many parents coming to see me to determine whether or not their child really has bipolar disorder.

Once I kept finding evidence of infections, and often positive mood or behavioral changes when the newly discovered illnesses were addressed, I decided that it was important that I go back and check for infections in my bipolar patients with whom I had worked for years. Again, I was surprised as I found that many of these kids also tested positive for evidence of infection, especially tick-borne illnesses (TBIs).

Ten years ago I learned that New Jersey, where my practice is located, is a Lyme endemic state (meaning it’s quite common). But how was it possible that so many of my patients tested positive? Maybe the testing was wrong? I even submitted samples of my own blood to two of the specialty laboratories (Igenex and Galaxy Diagnostics) to check the accuracy of the testing and found the results quite credible.

I also noted that as I kept learning more and more about Lyme and the other TBIs at different specialized meetings, I often heard presentations of adult patients who were diagnosed with bipolar disorder and later found to be suffering from some form of tick-borne illness. This sounded just like “my kids.”

With this experience as my background, I decided to do a retrospective chart review to determine the rate of evidence of tick-borne infection exposure in 27 consecutively seen bipolar youth whom I treated between February 2013 and July 2015. Of the 27, 81% (22/27) were males and 19% (5/27) were females with an average age of 7.3 years. Fifteen of the kids were were diagnosed as having Bipolar I (had manic episodes) and 12 had Bipolar II (episodes of depression with periods of hypomania). Using a variety of different laboratories, blood testing was done to check for evidence of exposure to Group A Beta Hemolytic Streptococcal bacteria, and other infectious agents including Mycoplasma pneumoniae (which can cause walking pneumonia), Borrelia burgdorferi (Lyme disease), Babesia, Bartonella, Anaplasma and Ehrlichia. In the end, 89% (24/27) showed evidence of exposure to one or more of these pathogens (infectious agents). The frequency of the positive testing results in the 27 bipolar child patients were as follows:

Babesia =16

Mycoplasma pneumoniae = 11

Bartonella = 8

Lyme = 6

Anaplasma + Ehrlichia = 1

All individuals who had a positive test, were recommended to see a doctor familiar with TBI to determine if the patient should receive the clinical diagnosis and get appropriate treatment. Twenty-two of the 24 agreed to this assessment. All of those children who followed the recommendation and sought consultation were found by the evaluating physician to meet the clinical criteria for the diagnosis of having TBIs.

In the end, 20/27 or 74% of those with PBD were positive for TBIs by both laboratory testing and clinician assessment. Four of the 27 (23.5%) patients tested were positive for PANDAS. Another important observation is that only three of the 27 with PBD had a known tick bite.

The results are clearly quite provocative. It’s important to keep in mind that the association found between TBIs and PBD does not mean there is a causal relationship. Interestingly, for some children, treatment of their TBIs resulted in variable degrees of improvement of their psychiatric symptoms. The case of P, presented earlier, is a clear example of how treating the infection improved the child's mental health. Studies are needed before making a definitive statement regarding the neuropsychological effects of treating underlying infections. It would be wrong to generalize the results from a small, specialized psychiatric practice without more evidential support from other pediatric populations.

I also noted that some of the kids in my practice exhibited what I call “bipolar-like” symptoms. They clearly do not fit the full criteria for a bipolar mood disorder yet exhibit definite elements consistent with a significant amount of mood unsteadiness, especially depression, as well as exhibit similar co-morbidity to youth with PBD. The potentially accompanying psychiatric illnesses include anxiety disorders (e.g. obsessive-compulsive disorder [OCD] and separation anxiety), ADHD and behavioral disturbances with intense temper outbursts. I can’t help but wonder how many of these children have been given the diagnosis of Disruptive Mood Dysregulation Disorder (DMDD) by other psychiatrists. This diagnosis was created as a way to help identify children who did not show clear mania or hypomania but who struggle with long standing temper dysregulation, sadness and irritability. Could many of them be in this “bipolar-like “ group? Again, the answer requires more study.

The natural question from these findings for both parents and professionals is: Does treating the TBI make any difference in how these kids actually end up functioning in real life?

Without more research, I can only comment about what I have observed in my practice with these children. There appears to be three groups:

  1. Kids who are treated for their bipolar symptoms as well as TBIs who at some point are able to do well once the infections are resolved or at least controlled. Their psychiatric symptoms appear to have been eliminated or significantly lessened enough that they are able to be off all psychiatric medication. This group is fairly small but definitely exists.

  2. Kids who are treated for BPD and TBIs but require less psychiatric medication (yet still need some) when their infections are under better control. One clue that the psychiatric medication can be lessened is the occurrence of side effects from the psychiatric medication (e.g. new onset of lethargy and sleepiness) that were previously not present while the child appeared to benefit from that dose of medication in the past.

  3. Kids who are treated for BPD and TBIs but still require significant doses of psychiatric medications as their infections come under better control.

The true prevalence of TBIs in youth who reside in the geographical area where my practice is located is unknown. This data is crucial to be able to interpret properly what I’ve found in my patients.

Do TBIs or other infections seen with PANDAS and PANS cause PBD or even Major Depressive Disorder in childhood? To what extent do infectious agents and autoimmune processes contribute to the present escalation in child and adolescent mental disorders? The mounting evidence supporting the connections of infections, autoimmune processes and mental disorders appears significant and demands more scientific investigation.


Relevant articles by Dr. Greenberg for more information:

  1. Greenberg, R. The Role of Infection and Immune Responsiveness in a Case of Treatment Resistant Pediatric Bipolar Disorder. Journal: Frontiers in Psychiatry, March 2017.

  2. Greenberg, R. Infections and Childhood Psychiatric Disorders: Tick Borne Illness and Bipolar Disorder in Youth Bipolar Disorder: Open Access Volume 3, Issue 1, 2017

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Jun 23, 2021


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