According to the study, depression has been reported in 8 – 45% of patients with post-treatment Lyme disease syndrome (PTLDS), but little was known about suicidal tendencies in these patients. The extent and severity of depression and suicidality was compared between PTLDS and HIV/AIDS patients, and a non-patient control group was compared. The results conclusively demonstrate that suicidal tendencies increase among patients who are depressed and that, perhaps surprisingly, depression experienced by PTLDS and HIV/AIDS patients was statistically indistinguishable. This seminal study highlights the fact that one in five patients with PTLDS reported suicidal thoughts and the importance of screening for depression and suicidality to optimize patient care.