Introduction

Lyme disease is a bacterial infection transmitted by the infected Ixodes tick. 

Globally, certain members of the bacteria Borrelia burgdorferi sensu lato species complex are linked to its cause — B. burgdorferi sensu stricto and potentially B. mayonii in North America, as well as B. bavariensis, B. burgdorferi, B. spielmanii, B. garinii, and B. afzelii in Europe.^1,3

Symptoms of lyme disease

The general symptoms that arise from this infection typically affect the skin, musculoskeletal system, heart muscles, eyes and central and peripheral nervous systems. 

However, psychological and neuropsychiatric impairment has also been linked to Lyme disease. It is not fully clear whether the psychological issues are comorbidities or rather consequences of living with the disease. However, an inflammatory connection has been suggested. This article further explores the association between Lyme disease and mental health.^{1, 3, 7,15}

What is lyme disease?

Symptoms 

Erythema migrans (EM) rash is considered to be the earliest sign of Lyme disease and is typically present in >70% of early disease cases. The primary EM lesion appears at the tick bite site, between a few days and up to one month following the bite. It commonly starts as a red macule/papule and, as the lesion expands, it can start appearing more like a red ring or a ring-within-a-ring. As the infection progresses, secondary EM lesions can also form in other parts of the body.¹

There are 3 key stages of Lyme disease – early localised, early disseminated and late. Below is a brief overview of each:²

• Early localised — red ring-like, expanding erythema migrans rash, following a recent tick bite, that appears at the site of the bite. Possible to exhibit flu-like symptoms, fever, myalgia (muscle pain), arthralgia (joint pain), headache, malaise (general discomfort/feeling unwell)
• Early disseminated – multiple lesions of erythema migrans. Other symptoms include arthralgia (joint pain), myalgia (muscle pain), flu-like symptoms, lymphadenopathy (swollen lymph nodes), ophthalmic conditions, lymphocytic meningitis, and cranial nerves palsies
• Late – arthritis, typically pauciarticular and impacting large joints²

Epidemiology

The ticks can be found in woodlands and grassy areas; however, not all of them carry Lyme disease. Certain occupations (e.g. farm workers) can increase the risk of getting bitten, but anyone who spends time outside can get infected. Central, Eastern and Northern Europe, the US and Canada and parts of Asia are reported to have higher prevalence. The Scottish Highlands have also been suggested to have high endemicity. Below are some of the factors that are suggested to contribute to the increase in Lyme disease incidence, as well as the high spatial variation across Eurasia and North America:^3,4,5

• Climate change 
• Changes in host communities 
• Changes in land use/land cover 
• Habitat fragmentation 
• Vegetation structure changes 
• Increased reporting and diagnosis³

Treatment

The main treatment for Lyme disease is antimicrobial therapy for 2-4 weeks, which helps to resolve the symptoms and signs of infection for most patients. The most commonly used antibiotics are doxycycline, amoxicillin and ceftriaxone. The patient's age as well as the stage of disease are key determining factors in the treatment selection. Most patients, except for pregnant women and children, receive doxycycline. However, amoxicillin is the drug of choice for children, while pregnant women have been reported to respond well to ceftriaxone.^2,6

For cases where the disease symptoms – such as fatigue, cognitive impairment and pain – persist after the antibiotic treatment has cleared the infection, a term post-treatment Lyme disease syndrome (PTLDS) is used.¹²

The effect of lyme disease on mental health

Psychological symptoms

In addition to the general Lyme disease symptoms, psychological and neuropsychiatric impairment have also been associated with the infection. It is not entirely clear whether the mental health issues arise as comorbidities or are a consequence of dealing with the disease. This involves problems, such as:^{7, 8}

• Depression 
• Problems with sleep 
• Mood swings
• Personality disorders
• Concentration, memory and thinking 
• Paranoia 
• Panic attacks
• Anorexia nervosa
• Obsessive-compulsive disorder
• Bipolar disorder
• Dementia 
• Schizophrenia^{7, 8}

Some of the interesting scientific findings on this topic are summarised below:

• In a nationwide Danish cohort study, patients with Lyme disease have been reported to exhibit higher rates of mental health and affective disorders, suicide attempts and death by suicide, compared to individuals without the disease
• The quality of life has been reported to be worse in the Lyme disease study group, compared to unaffected individuals. This study also reported significant differences in memory performance and attention between the two groups. 68% of the patients in the Lyme disease group also showed clinically relevant depression
  • Another important finding concluded from this study was that Lyme disease patients have to wait an average of eight years before receiving their diagnosis, as well as see an average of eight physicians 
• There has also been a case report of a patient, with no known psychiatric history, who developed severe depressive symptoms, panic attacks and suicidal ideation as well as exhibited neuromuscular issues, with these symptoms arising two years following successful Lyme disease treatment¹
• Patients with early Lyme disease have been reported to exhibit poor sleep quality, which can further be linked to the typical pain and fatigue symptoms associated with this infection^{7, 9,10,11} 

It can often take a long time and multiple visits to the doctor to receive the correct Lyme disease diagnosis; its symptoms can also be mistakenly considered to have a psychological cause. This leads to patients receiving the wrong treatment, this way allowing for the Lyme disease to advance and complicates the further treatment of the infection. Anxiety, depression, as well as other psychological symptoms, can be some of the first signs of Lyme disease, further complicating the process of diagnosis.^7,15

It has been suggested that this disease also affects the mental resilience of the sufferers; the patients do not have enough energy to cope with their everyday responsibilities and cannot work for a prolonged time. They often withdraw from their social environment, and, due to their changeable symptoms, it also becomes difficult for the patients to plan their lives. Given the high level of potential psychological impairment seen in Lyme disease, psychotherapist support is recommended.⁷

While it is not entirely clear what mechanisms underlie the link between Lyme disease and mental health, a psychiatrist suggested an inflammatory connection, noting that any infection that can cause an encephalitis, which means inflammation in the brain, can cause psychiatric disorders, adding that Borrelia can do it as well.¹⁵

Memory and cognitive issues

It has been noted that patients suffering from the post-treatment Lyme disease syndrome (PTLDS) have reported cognitive complaints. 

For instance, a study that evaluated the cognitive functioning of PTLDS patients suggested that memory impairment and variable processing speed decline are the key significant cognitive deficit measures, found in 26% of the study sample.¹³

Furthermore, PTLDS can be mistakenly neuropsychologically confused with major depressive disorder (MDD) as both diseases have a similar extent of psychomotor slowing. A study reported that issues in memory-related tasks, although mild, were more pronounced in PTLDS patients compared to MDD. Additionally, PTLDS sufferers exhibiting worse memory also had worse language fluency, however, showed less deficit in attention and psychomotor speed in comparison to MDD patients.¹⁴

Psychological coping strategies

It was suggested that the cognitive behavioural therapy (CBT) approach is quite homework-intensive, for instance, maintaining a daily log or a diary. This may be overwhelming for patients who are coping with challenges like fatigue and brain fog. Furthermore, the aspect of CBT that deals with managing distorted thoughts doesn’t make much sense for patients with Lyme disease either, given that their thoughts are not necessarily distorted and rather revolve around real-life struggles associated with their disease.¹⁵

Trunzo further suggested that he observed some success when incorporating the acceptance and commitment therapy (ACT). According to his description, ACT focuses less on thought pattern restructuring and more on adaptation to current reality. With the ACT strategy, the patients still identify the thoughts they struggle with, but this approach tries to help the patients learn how to co-exist with/accept the thoughts in a way that allows them to still live in the moment. Trunzo also noted that while no studies investigated the effect of ACT specifically in Lyme disease patients, other research has shown it to be effective in patients with other chronic illnesses.¹⁵

Summary 

Lyme disease is a tick-borne infection, prevalent in Europe, the US and Canada and parts of Asia. 

The main distinguishing symptom of this infection is the Erythema migrans rash, which begins as a red macule/papule and then as a red ring/ring-within-a-ring. 

Patients with Lyme disease can suffer from depression, sleep disturbances, mood swings and panic attacks, problems with concentration, memory and thinking.

The exact underlying mechanism is unknown; however, inflammation of the brain has been suggested to play a role. It is also not clear whether the mental health issues arise as comorbidities or as a result of the disease burden. 

Often, it takes a long time for the patients to receive the correct Lyme disease diagnosis, and their symptoms can be mistaken for having a psychological cause, leading to the wrong treatment choice.

The acceptance and commitment therapy (ACT) that focuses on adaptation to the current reality has been suggested to potentially be an effective coping strategy for patients dealing with Lyme disease.^{1, 4, 7,15}