Suicidal and homicidal tendencies after Lyme disease: an ignored problem.

Dear editor We would like to applaud the author for conducting such an important study by performing a comprehensive assessment of suicide and its association with Lyme-associated diseases (LADs).1 It is the first study of its kind, and it raises a need for further investigation on this subject. Suicide is a major health care issue in the USA, contributing to almost 42,773 deaths in the USA in 2014.2 There is no data available specific to suicide associated with LAD. Dr Bransfield inferred the possible prevalence of suicide associated with LAD by an indirect method which revealed that 414,540 patients with LAD have suicidal ideation, 31,100 attempt suicide and a total of 1,244 commit suicide in the USA per year from LAD.1,2 Several cases have been reported highlighting the issue of an association between suicide and LAD. A case report published in 2013 by Banerjee et al is an example where a case of 44-year-old male without any past psychiatric history presented with a third unsuccessful suicide attempt and was later diagnosed as having Borrelia infection. After 1 month of medical therapy with intravenous ceftriaxone, resulted in improvements in his mental status and resolution of suicidal ideation.3 Another set of cases was reported earlier in the 1990s by Fallon et al, highlighting suicidality in patients with Lyme disease. One of the two patients presented with neurological symptoms including fatigue, frontal headaches, and memory loss, and the second with a flu-like illness, joint pain, swollen glands, and fever. After further investigations, both of these patients were diagnosed with Lyme disease and appropriate treatment was offered. Few months after the treatment, both patients developed severe depression along with suicidal threats and an attempt by one patient. An evidence of persistent Lyme borreliosis was found in both cases.4 Another study reported in 2002 by Juchnowicz et al suggested that patients with Lyme borreliosis can experience psychiatric issues during both acute and late phases of the disease, most common being depression.5 In some cases, it slowly progresses to severity and suicidality as explained in the above cases, but in some cases, it is unpredictable. As evident from the above-reported cases, depression usually precedes suicidality. These reports point to a need of thorough case studies to find a link between such an important association, so that we can treat it accordingly. Although there is evidence proving the relationship of suicidality with LAD in this study, there is still a need for a more elaborative prospective cohort study highlighting different stages of the disease and percentage of people who develop suicidal thoughts during the disease course and to understand different patterns of development of such thoughts. No direct study has been conducted to estimate the prevalence of patients with LAD who committed suicide or had suicidal ideation. Also, more evidence is needed for a better understanding of the pathophysiology and biochemical mechanisms leading to depression and suicide in these patients. There is also need to explore the relationship of chronicity of Lyme borreliosis with other psychiatric diseases, such as bipolar disorder, leading to suicidal thoughts and attempts.