Mental health impact of dengue fever

Dengue fever is a major public health concern in tropical countries, including India and other South Asian nations, with peak incidence during and immediately after the monsoon months. It is the fastest spreading vector-borne viral disease. It is caused by the dengue virus (DENV), a flavivirus with five serotypes (DENV 1-5), and transmitted by Aedes aegypti and Aedes albopictus. It comprises three clinical phases: febrile (2–7 days), critical (24–48 hours), during that there is risk of shock or bleeding due to plasma leakage, and recovery. Dengue fever encompasses a wide range of symptoms, from mild flu-like symptoms to dengue hemorrhagic fever and dengue shock syndrome, with the high case fatality rate. Psychological reactions to Dengue can occur before, during, and after the infection. The psychiatric sequelae of dengue fever are no longer anecdotal and have become a well-established aspect of the illness. Psychiatric manifestations may arise before the onset of the illness, during the acute phase, or during the convalescent period.[1] PSYCHOLOGICAL REACTIONS BEFORE INFECTION: ANTICIPATORY ANXIETY AND FEAR The constant fear of dengue infection can lead to fear and anticipatory anxiety in populations of endemic areas. Several factors induce the pre-infection psychological burden. Firstly, the widespread presence of mosquitoes in India creates a sense of vulnerability. Individuals may experience heightened vigilance, worrying about mosquito bites and the potential risk of contracting the disease, which can lead to irritability, chronic stress, and difficulty concentrating. Secondly, the public health campaigns that are crucial for awareness can inadvertently contribute to anxiety by emphasizing the potentially fatal outcomes of Dengue. Sensationalized, repeated media reports of increasing case numbers or deaths can amplify fear, leading to a state of chronic stress and even panic in some individuals.[2] PSYCHOLOGICAL REACTIONS DURING INFECTION: ACUTE DISTRESS AND COGNITIVE IMPACT The onset of dengue infection, presenting with the high fever, severe headaches, retro-orbital pain, excruciating muscle and joint aches, and a skin rash, is extremely frightening. Patients often experience severe anxiety, fear, and emotional lability. Depressive symptoms are also common during the acute phase. The profound fatigue, loss of appetite, nausea, vomiting, and general malaise can lead to feelings of hopelessness, despair, and anhedonia. Due to fatigue and weakness, the patient may be confined to bed, leading to social isolation, further exacerbating their mood disturbances. The dengue virus can also affect the central nervous system, leading to the symptoms such as confusion, disorientation, impaired concentration, memory deficits, and delirium.[3] These cognitive impairments can significantly compound the psychological burden, making it difficult for patients to understand medical instructions, make decisions, or even articulate their feelings.[4] Sleep disturbances are reported due to pain, fever, and anxiety. PSYCHOLOGICAL REACTIONS AFTER INFECTION: POST-DENGUE SYNDROME AND LONG-TERM IMPACT Many individuals report persistent fatigue, weakness, muscle and joint pain, and a general feeling of being unwell for weeks or even months after physical recovery. This prolonged physical debility can affect daily activities, work productivity, academic performance, and overall quality of life, leading to frustration, resentment, and a sense of loss of control. Depression and anxiety are common long-term sequelae. The experience of severe illness, the fear of recurrence, and the lingering physical symptoms can trigger or exacerbate mood disorders. Some individuals may develop post-traumatic stress disorder (PTSD)-like symptoms, especially if they experienced severe Dengue, hospitalization, or perceived a life-threatening situation. Flashbacks, nightmares, avoidance behaviors, and hyper-vigilance related to the illness can impair their psychological well-being.[4] The social and economic consequences of Dengue, viz., loss of income due to inability to work, medical expenses, and the stigma associated with the disease, can lead to financial strain and social isolation, further impacting mental health. Children may experience prolonged school absenteeism, developmental delays, and behavioral changes following dengue infection. COPING MECHANISMS AND SUPPORT Providing reassurance and accurate information about Dengue, managing expectations regarding recovery, and offering psychological counseling that can alleviate anxiety and fear. Healthcare providers should be trained to recognize and address psychological symptoms, integrating mental health screening into routine dengue care. Family and community support play a crucial role in the recovery process, helping individuals cope with the physical and psychological challenges. Promoting healthy lifestyle choices, such as adequate rest, proper nutrition, and a gradual return to physical activity, can also aid in recovery and enhance mental well-being. PSYCHIATRIC SEQUELAE Existing literature does not cite the exact prevalence and incidence rates of the psychiatric sequelae due to a dearth of observational studies. However, the case series and reports can fairly help in delineating the manifestations, which include anxiety, depression, mania, psychosis, obsessive-compulsive, and related disorders.[5] Anxiety symptoms are reported in as high as 80% of individuals in the acute phase of Dengue. The symptoms usually subside as the patients move into the recovery phase. However, for some, it persists during recovery and well after it, too, putting individuals at an increased risk of anxiety disorders. Thanatophobia during the illness, and entomophobia have been reported during and after the disease as well. Depressive symptoms frequently co-occur with anxiety symptoms.[6,7] Depressive symptoms were observed in 60-80% of the cases. Although these symptoms were predominant in the acute phase of the illness, they were not uncommon in the post-dengue phase, with studies suggesting prevalence rates ranging between 15% and 34% in up to two years post-infection, and in general, placing the individuals at a higher risk for depressive disorders during their lifetime.[4,6] Mania following dengue fever typically occurs in the acute phase or immediately after recovery, from the third day of illness up to two weeks following recovery.[5] Most of the evidence from mania comes from case reports[8-10] and only one case series,[11] in which all the cases reported developed symptoms shortly after recovery. Symptoms of all the reported cases are consistent with mania, and not hypomania. A low platelet count was a consistent finding in most cases, suggesting a correlation between manic symptoms and the severity of dengue fever.[5,8-11] Psychotic symptoms have been reported both during and after the infection. Some of the cases with psychosis occurred in the background of dengue shock syndrome or dengue encephalitis, hence confounding the psychopathology of psychosis. The psychotic symptoms mainly comprised disorganized behaviors, delusions, and hallucinations in visual and auditory modalities. Catatonia has also been documented in a case report. There have been retrospective cohort studies suggesting the possibility of post-dengue psychosis as well, but meager data make it difficult to ascertain the exact prevalence.[6,12] A Brazilian study attempted to evaluate the correlation between dengue fever and hoarding disorder, also known as Diegones syndrome. One case report documented body dysmorphic disorder due to telogen effluvium following Dengue. Disturbed sleep patterns are present for up to a year after dengue fever. However, they may be included as a part of other psychiatric or organic illnesses, as no confirmatory evidence has been laid out for insomnia secondary to Dengue.[5,13] PATHOGENESIS The pathogenesis of psychiatric manifestations following dengue infection is an intricate interplay of various factors, including the direct effect of the virus on the central nervous system, neuroinflammation that breaches the blood-brain barrier (BBB) and disrupts neurotransmitter pathways, systemic and hemodynamic insults, and immunological and epigenetic modifications.[1,14] Pathological and molecular studies suggest that the dengue virus can be detected in brain tissues and potentially exerts direct cytopathic effects due to neurotropism.[1,15] The viruses have a deleterious effect on the endothelial cells of the BBB, which can be culpable for independent inflammatory activation and insults to neuronal and glial cells.[15] Dengue virus infection sets forth a robust pro-inflammatory cytokine cascade, comprising IL-1β, IL-2, IL-6, and TNF-α. This cascade can disrupt the BBB’s integrity, precipitating neuroinflammatory processes that may explain the psychiatric sequelae. Neurotransmitter systems, most notably the serotonergic pathways, are susceptible to neuroinflammation and may explain the underlying psychiatric manifestations. Elevated cytokine levels cause tryptophan depletion, thereby impeding serotonin synthesis and precipitating depressive and anxiety symptoms. IL-1 and TNF-α also disrupt glutamatergic homeostasis.[2] Systemic factors characteristic of dengue shock syndrome, such as hypovolemia, cerebral hypoperfusion, hepatic dysfunction, and metabolic derangement, are also contributory to mood lability and disordered thought processes.[1,16] Antibody-dependent enhancement and immune-complex-mediated vascular injury result in capillary leaks and hemorrhages, which further exacerbate the risk of neuropsychiatric sequelae.[17] Specific epigenetic mechanisms have also been implicated in explaining these psychiatric manifestations. The most relevant is the activation of the histone deacetylases (HDACs). The infection triggers oxidative stress, activating HDACs and inhibiting gene regulatory pathways that control mood and behavior.[18] Gene studies have revealed that DENV infection can modify gene-regulatory pathways and cause disruptions in dopaminergic signaling, offering a plausible explanation for psychosis and affective disturbances.[14,15] Other than these acute models of pathogenesis, delayed immune-mediated mechanisms, such as molecular mimicry and autoantibody formation, have been proposed to explain the occurrence of post-infectious syndromes with psychiatric phenotypes.[15] Taken together, these convergent mechanisms explain why psychiatric manifestations of Dengue are heterogeneous, temporally variable, and sometimes discordant with conventional neuroimaging or CSF markers. MANAGEMENT The first step in managing the psychiatric symptoms is, in fact, optimizing the medical milieu, which may result in resolution of the psychiatric symptoms without the need for psychotropic medications. However, often, psychotropic medications must be incorporated into the treatment regimen, especially in the acute cases. Literature supports the use of low-dose antipsychotics for psychosis and acute mood disturbances, benzodiazepines in catatonia, and mood stabilizers for post-dengue affective disorders. Anxiety disorders, depressive episodes, and body dysmorphic presentations respond well to selective serotonin reuptake inhibitors. Non-pharmacological strategies, including psychoeducation, supportive psychotherapy, and cognitive rehabilitation, serve as valuable adjuncts, particularly in convalescence when patients experience residual anxiety, depression, or difficulty in adjustment post the illness. Advances in immunopsychiatry and epigenetics raise the possibility of targeted interventions, such as histone deacetylase inhibitors, for mood regulation; however, these are still under investigation.[15] The overarching principle is vigilance: prompt recognition, collaborative care between physicians and psychiatrists, and an individualized plan that balances symptomatic relief with the safety and security. CONCLUSION The mental health burden on individuals and communities is substantial. Therefore, a comprehensive public health strategy for Dengue must integrate mental health considerations, provide robust psychological support and fostering resilience among affected populations. Future advances in understanding the psychiatric sequelae of Dengue depend on systematic epidemiological studies, which can supersede the available case reports and series, providing insight into the prevalence and trajectories of the sequelae and thereby making it possible to devise effective interventions. Psychiatrists and medical practitioners must anticipate mood, anxiety, and psychotic disorders in both acute and convalescent phases, ensuring early detection and integrated care. Public health systems should incorporate psychiatric screening into dengue management protocols to reduce long-term morbidity and mortality. For the general population, awareness of mental health consequences may facilitate timely help-seeking. Authors’ contributions Concept and design of paper: SC, TA. Drafting the article and revising it critically for important intellectual content: TA, SC. Final editing, and approval of the version to be Published: SC, TA, JP, KS. The manuscript has been read and approved by all authors.