Neurological and Psychiatric Sequelae at 6-Months Post-COVID-19

Written by: Sam Bazzi
Edited by: Esther Melamed

Neurological and psychiatric symptoms have been established as a common symptom and sequelae of COVID-19, but our understanding of how long neurological and psychiatric problems persist after infection is limited. A recent report from Taquet et al., published in The Lancet, describes a retrospective cohort study that analyzed the electronic health records of over 200,000 COVID-19 patients in order to track neurological and psychiatric health outcomes at 6 months post-infection.

The authors enrolled patients from three cohorts: patients diagnosed with COVID-19, matched controls diagnosed with influenza, and matched controls diagnosed with any respiratory tract infection including influenza (but not COVID-19).

“[They] estimated the incidence of 14 neurological and psychiatric outcomes in the 6 months after a confirmed diagnosis of COVID-19: intracranial haemorrhage; ischaemic stroke; parkinsonism; Guillain-Barré syndrome; nerve, nerve root, and plexus disorders; myoneural junction and muscle disease; encephalitis; dementia; psychotic, mood, and anxiety disorders (grouped and separately); substance use disorder; and insomnia.” (Taquet et al., 2021)

They also correlated the incidence of these symptoms with COVID-19 severity, which they determined using hospitalization, ICU admission, and encephalopathy.

They found that the incidence of neurological or psychiatric diagnosis within the 6 months following COVID-19 infection was 33.62%, with 12.84% being a first-time diagnosis. Among patients admitted to the ICU, the incidence was 46.62%, with 25.79% being a first-time diagnosis. Patients with COVID-19 were more likely to experience almost all of the major neurological and psychiatric outcomes assessed in this study. One interesting exception was that Guillain-Barré syndrome (GBS) was not significantly higher in COVID-19 relative to influenza – a result that I found intriguing because of the large number of published case studies on GBS in COVID-19, but ultimately makes sense because GBS can follow other types of viral infection.  Another exception was that parkinsonism was not significantly higher in COVID-19 relative to influenza but was significantly higher relative to other respiratory tract infections. Other neurological and psychiatric conditions that had significant hazard ratios (HR) were stroke (HR of 1.8), dementia (1.88), psychotic disorder (HR 1.46), and substance abuse disorder (HR 1.27). Further, patients who were admitted to the intensive trauma unit or had encephalopathy experienced higher rates of neurological or psychiatric complications within 6 months.

Overall, this study demonstrates that neurological and psychiatric sequelae are very common in COVID-19 and persist for long periods of time after infection. These symptoms likely contribute to what is commonly called “long haul COVID” but our understanding of why these symptoms persist is unclear thus far.