Is insomnia a part of long COVID (Coronavirus Disease 2019) syndrome?

Insomnia as a Component of Long COVID Syndrome

Yes, insomnia is a significant component of long COVID syndrome, affecting approximately 22% of patients with persistent symptoms beyond 12 weeks after COVID-19 infection. 1

Prevalence and Characteristics of Sleep Disturbances in Long COVID

• Sleep disturbances, particularly insomnia, are among the commonly reported symptoms in long COVID, with prevalence rates ranging from 11% to 44% across different studies 1
• In a comprehensive study of post-COVID patients, 25.3% reported sleep-related symptoms, with insomnia being the predominant complaint (22.2% of all long COVID patients) 2
• The prevalence of significant insomnia in long COVID patients was found to be as high as 50% at initial evaluation and 42% at follow-up visits in a COVID-specific clinic 3
• A recent cross-sectional study reported an even higher prevalence of 63.12% among COVID-19 survivors, with varying degrees of severity: 35.82% with sub-threshold symptoms, 20.57% with moderate symptoms, and 6.74% with severe symptoms 4

Relationship to Other Long COVID Symptoms

• Insomnia in long COVID often co-exists with other neurological and cognitive symptoms, including fatigue, cognitive impairment ("brain fog"), memory loss, and sensorimotor symptoms 1
• Sleep disturbances are part of the broader neurological manifestations of long COVID, which affect the quality of life and daily functioning of patients 1
• Cognitive impairment, which is found in 22% of patients with COVID-19 at 12 weeks post-infection, often occurs alongside sleep disturbances, creating a complex symptom pattern 1

Risk Factors for Insomnia in Long COVID

• Female sex is consistently associated with a higher risk of developing long COVID symptoms, including insomnia, with women having approximately twice the risk compared to men 1, 3
• Younger age groups appear to be more vulnerable to insomnia symptoms following COVID-19 infection 3, 4
• Pre-existing depression is a significant predictor of post-COVID insomnia development 5
• Other risk factors include:
  • Non-White race and non-Hispanic ethnicity 3
  • Higher educational levels and certain occupations 4
  • History of steroid use during COVID-19 treatment 2
  • Social isolation and living alone 6
  • Financial burden related to the pandemic 6

Pathophysiological Mechanisms

• The exact mechanisms underlying insomnia in long COVID are not fully understood, but several pathways have been proposed:
  • Neuroinflammation and immune dysregulation affecting brain regions involved in sleep regulation 1
  • Activation of the kynurenine pathway, with metabolites like quinolinic acid associated with cognitive and sleep disturbances 1
  • Possible viral persistence in tissues, including neurological structures 1
  • Autonomic nervous system dysfunction (dysautonomia) affecting sleep-wake cycles 1

Clinical Course and Persistence

• Insomnia symptoms can persist for months to years after the initial COVID-19 infection 1
• A longitudinal analysis found that while some mental health conditions like anxiety and depression may improve over time, sleep disturbances and cognitive symptoms can persist for at least 2 years 1
• The course of post-COVID insomnia may follow different patterns: symptoms may lessen over time, slightly worsen, or develop into mild chronic insomnia 5

Management Considerations

• Despite the high prevalence of insomnia among COVID-19 survivors, over half (51.97%) do not take any measures to address their sleep problems 4
• Among those who seek treatment, pharmacological interventions (25.28%), physical exercise (11.80%), or a combination of both (4.78%) are the most common approaches 4
• Improvements in insomnia severity correlate with improvements in anxiety and post-traumatic stress disorder symptoms, suggesting that addressing psychological comorbidities may help manage sleep disturbances 3
• Evidence-based approaches such as cognitive behavioral therapy for insomnia (CBT-I) may be particularly suitable for post-COVID insomnia 3

Conclusion

Insomnia represents a significant component of the long COVID syndrome, affecting approximately one-fifth to one-half of patients with persistent symptoms. It is part of a constellation of neurological and cognitive manifestations that can significantly impact quality of life and daily functioning. The recognition and appropriate management of insomnia should be an integral part of the comprehensive care approach for long COVID patients.