Background: A growing body of evidence suggests a relationship between inflammatory responses to infections and several health conditions, including psychiatric illness. This study explored possible links between exposure to tick-borne pathogens (TBP) and pediatric bipolar disorder (PBD).
Methods: A retrospective case series of 27 bipolar youth from a single Northeast US practice was used to examine rates of exposure to TBP. Bipolar diagnoses were based on DSM-IV TR criteria using information from parent questionnaires, clinical interviews with parents and children, and school reports. Blood specimens provided between February 2013 and July 2015 were assessed for exposure to TBP: Borrelia Burgdorferi (lyme disorder), Babesia, Bartonella, Mycoplasma Pneumoniae, Anaplasma, Ehrlichia, and other rickettsial diseases. Lyme testing was performed using ELISA and Western Blot IgG/IgM; Babesia and Bartonella were ascertained by IgG/IgM titers and fluorescent in-situ hybridization (FISH) tests; other pathogens were tested using IgG/IgM titers. Testing was performed at Lab Corp, Mayo Medical, Igenex Laboratories, Galaxy Diagnostics or Fry Labs. Diagnosis of tick borne illness (TBI) was based on clinician evaluation of symptoms, physical examination, and laboratory results. Descriptive statistics were used to summarize the data.
Results: Fifteen youth met the criteria for Bipolar I; 12 had Bipolar II. Mean age at diagnosis was 7 years (range 5–12); 81% were male and 19% female. Serological evidence of one or more TBP was found in 24 of 27 (89%) patients. The most common pathogens were: Babesia (n = 15), Mycoplasma Pneumoniae (n = 10), Bartonella (N = 9), and Lyme (n = 6). Twenty-two of the 24 serologically positive patients had further clinical evaluations; 20 of 22 (91%) were diagnosed with TBI.
Conclusions: The high rate of TBI in PBD patients in this case series is provocative. If confirmed, this association may suggest gene-environment interactions with implications for the prevention and treatment of PBD, as well as other childhood mood disorders.