Lyme borreliosis is a multisystemic infectious disease caused primarily by spirochetes belonging to the Borrelia burgdorferi complex, which are transmitted by ticks. It is classically associated with involvement of the skin, joints, heart and nervous system, but since the 1990s, more and more data has been collected indicating that Lyme disease can also cause neuropsychiatric symptoms and mimic or exacerbate psychiatric conditions. Fallon’s research in 1994 already pointed out that Lyme disease can be associated with neurological involvement in up to 40% of cases and a wide range of psychiatric disorders – paranoia, dementia, schizophrenia-like states, bipolar symptoms, panic disorder, major depression, anorexia nervosa, and obsessive-compulsive disorder – may occur at various stages of the disease. The significance of psychiatric symptoms lies in the fact that, on the one hand, they can cause diagnostic difficulties and, on the other hand, they can dramatically impair the quality of life and functioning of affected patients, even though the underlying infection is treatable.
Depression and anxiety disorders in Lyme disease
Mood disorders are among the most commonly described psychiatric manifestations in Lyme disease. In the late stage of Lyme disease, the prevalence of depressive states ranges from 26% to 66% in various studies. Depression is often accompanied by pronounced fatigue, sleep disturbances, cognitive slowing and somatic complaints, so the clinical picture can easily be confused with primary major depressive disorder or chronic fatigue syndrome.
Anxiety symptoms are also common: generalised anxiety, panic attacks, phobic symptoms, and intrusive phenomena similar to post-traumatic stress disorder (=intrusive thoughts) have also been described. Anxiety may be partly the result of neurobiological processes (neuroinflammation, neurotransmitter disorders), but it can also be interpreted as a psychological reaction related to the experience of illness, diagnostic uncertainty and chronic physical symptoms. It is the clinician’s task to carefully consider whether psychological symptoms should be interpreted as part of a “primary” psychiatric disorder or as a secondary, organic or reactive phenomenon.
Psychosis, bipolar symptoms and personality changes
Although less common, Lyme patients with psychotic and bipolar symptoms pose a significant clinical challenge. Case studies and small case series describe paranoid delusions, hallucinations, schizophrenia-like symptoms, and episodes resembling bipolar mood disorder in both adults and adolescents. Neuroimaging studies show frontal-subcortical abnormalities, mild white matter lesions, and perfusion abnormalities in some cases, but structural imaging is often negative.
According to Bransfield’s study, the immunological and metabolic disorders that appear in the various stages of Lyme borreliosis can create a clinical picture that suggests a diagnosis of schizoaffective or bipolar disorder, while Lyme infection is the underlying cause. From a clinical point of view, it is important to consider atypical, late-onset psychotic or affective disorders that respond poorly to treatment – especially those involving tick-related events or a history of exposure to Lyme – we should consider an organic background and, if necessary, request a consultation with an internal medicine/neurology/Lyme specialist.
It is common for patients and their relatives to report personality changes: previously balanced, well-functioning individuals become irritable, unstable, impulsive, suspicious, their social relationships narrow, and their ability to work deteriorates. These changes may be closely related to functional abnormalities affecting the frontal networks and the psychological consequences of chronic illness.
Cognitive impairment and Lyme encephalopathy
The cognitive symptoms associated with Lyme disease are mostly mild to moderate, but can still be very disturbing for patients. The most commonly reported symptoms are memory problems, difficulty concentrating, mental sluggishness and “brain fog”, which can impair the ability to perform everyday tasks and affect performance at work or school. This condition is often referred to as Lyme encephalopathy and typically occurs months to years after the onset of infection, with mild neurological symptoms or even without them.
Meta-analyses have confirmed that neurocognitive symptoms are significantly more common among patients who have had Lyme borreliosis than in control populations, and these symptoms can persist for years. The cognitive profile is partly distinct from the pattern observed in fibromyalgia, primary depression, or chronic fatigue syndrome, suggesting that specific neurobiological mechanisms may be involved.
Imaging studies, particularly SPECT, often reveal diffuse cerebral hypoperfusion, mainly in the frontal regions, which may correlate with impaired executive functions and attention processes. Although MRI often shows negative or only non-specific white matter lesions, functional abnormalities may well explain the patients’ subjective complaints.
Sleep disturbances, fatigue and reduced quality of life
Sleep disturbances and chronic fatigue associated with Lyme disease are not only part of the neurological and internal medicine symptomatology, but also contribute directly to the psychiatric picture. Patients often report difficulty falling asleep, frequent night-time awakenings, non-restorative sleep and morning exhaustion. Chronic fatigue and sleep fragmentation (= restless, constantly interrupted sleep) in themselves predispose to depression, anxiety, irritability and impair cognitive performance.
Suicide risk and behavioural disorders
In recent years, increasing attention has been paid to the suicide risk associated with Lyme disease. According to Bransfield’s review, neuropsychiatric conditions associated with Lyme borreliosis – particularly depression, mood instability, impulsivity and chronic pain – may collectively increase the risk of suicidal thoughts and attempts. In addition, some case reports have linked aggressive, impulsive behaviour and even violent acts to untreated or late-stage neuroborreliosis, although the causal relationship in these cases is often unclear.
Psychiatric diagnosis and differential diagnostic challenges
Recognising the psychiatric symptoms of Lyme disease is a serious challenge, as the clinical picture is often non-specific and overlaps considerably with other psychiatric and somatic conditions. A detailed medical history is key to the diagnostic process, with particular attention paid to tick exposure, previous episodes of erythema migrans, other Lyme-typical symptoms (joint complaints, radicular pain, facial paresis, symptoms of meningitis) and the temporal course of symptoms.
In Central Europe, it is advisable to consider the possibility of Lyme borreliosis in patients with atypical symptoms and multiple organ complaints who have visited several specialists, especially if neurological and rheumatological symptoms are also present. At the same time, serological tests (ELISA, Western blot) must be performed with caution, as both false-positive and false-negative results can be misleading, and inappropriate, prolonged antibiotic treatment can carry unnecessary risks. If available, direct diagnostic methods should be used, as they can provide more accurate results.
In psychiatric practice, atypical onset (e.g. psychosis starting at a late age), behavioural changes that differ from the patient’s previous personality, the co-occurrence of cognitive symptoms and neurological signs, and a partial or unusual response to standard psychopharmacological treatment may indicate an organic background. In such cases, a neurological consultation, cerebrospinal fluid analysis if necessary, imaging procedures (MRI, SPECT), and Lyme-specific testing are warranted.
Treatment considerations: an integrated approach
The treatment of psychiatric symptoms of Lyme disease is based on two main pillars: antibiotic-neurological treatment on the one hand, and psychiatric interventions on the other. According to current guidelines, confirmed Lyme borreliosis requires adequate, timely antibiotic treatment, which is often administered orally in the early stages and intravenously in late or neurologically affected cases. Some neuropsychiatric symptoms improve after antibiotic therapy, especially in cases of Lyme encephalopathy and depressive symptoms. In other cases, symptoms only partially regress and long-lasting psychological and cognitive consequences may remain.
The spectrum of psychiatric treatment includes antidepressants, anxiolytics, antipsychotics, mood stabilisers, and psychotherapeutic methods, especially cognitive behavioural therapy, illness processing therapy, and rehabilitation programmes. In addition to all this, multidisciplinary cooperation is key: the joint work of Lyme specialists, neurologists, psychiatrists, psychologists and rehabilitation specialists is necessary for the effective treatment of the complex symptom complex and the reintegration of the patient.
Summary
The psychiatric symptoms of Lyme disease cover a wide spectrum, ranging from depression and anxiety to cognitive impairment, personality changes and sleep disorders, to rarer psychotic and bipolar symptoms, and even an increased risk of suicide. Complex pathomechanisms lie behind the neuropsychiatric manifestations, in which direct neuroinfection, neuroinflammation, vascular abnormalities and psychosocial factors all play a role. The greatest challenge for clinicians is to deal with diagnostic uncertainty and to determine the extent to which Lyme borreliosis contributes to the psychiatric picture in a given patient.
In practice, a high degree of suspicion is key: in patients with a history suggestive of Lyme disease, atypical co-morbid physical and psychological complaints, cognitive impairment and neurological symptoms, it is reasonable to consider the role of Lyme disease. The best patient care requires a multidisciplinary approach, an empathetic, validating attitude and the consistent application of the biopsychosocial model. It is the psychiatrist’s responsibility to consider Lyme disease, especially in cases of neuropsychiatric symptoms, not merely as a rare infectious disease, but as an integral part of differential diagnosis.
Sources:
https://pubmed.ncbi.nlm.nih.gov/7943444/
https://pubmed.ncbi.nlm.nih.gov/30149626/
(C) Lyme Borreliosis Foundation
