In an assessment of 2-year retrospective cohort studies, the trajectories of the risks over the first two years following diagnosis showed significant disparities. Additionally, it was shown that risk profiles and trajectories differ between variants of SARS-CoV-2 and in children contrasted to adults and older individuals. Up to two years after the initial COVID-19 infection, researchers sought to evaluate the COVID-19 risks for a variety of psychiatric and neurological outcomes.

Extraction of data was done from TriNetX electronic health records network. Propensity-score matching (1:1) was done between a cohort of subjects with COVID-19 of any age and a concurrent cohort of subjects with any other respiratory infection. Immunization status, risk factors for COVID-19 and severe SARS-CoV-2 infection, and demographic factors were used to match patients.

The date of diagnosis and age groups (children under 18 years of age, adults between 18 to 64 years of age, and older adults 65 years old and older) were used to stratify the analyses. Following COVID-19 infection, the risks of 14 psychiatric and neurological disorders were evaluated and these risks were contrasted with matched comparator sample.

Using time-varying hazard ratios (HRs), representation of the 2-year risk trajectories was done.

With the aid of 6-month constant HRs (illustrating risks in early period of follow-up, which have not previously been thoroughly characterized in children), the risk horizon for each outcome (i.e., time at which HR returns to 1), and time to equal incidence in both cohorts, the 2-year risk trajectories were summarized.

It also provided an estimate of the number of persons in each age group who passed away following a psychiatric or neurological diagnosis. Additionally, the matched cohorts of individuals with SARS-CoV-2 infection were compared prior to and after the development of the alpha (B.1.1.7), delta (B.1.617.2), and omicron (B.1.1.529) variants.

A total of 1 487 712 individuals infected with SARS-CoV-2 were recognized, of whom 1 284 437 (242 101 older adults, 856 588 adults, and 185 748 children; 542 192 [42.2%] were male and 741 806 [57.8%] were female; overall mean age 42.5 years [SD 21.9]) were matched appropriately with a similar number of subjects with another respiratory ailment.

The risk profiles of outcomes following COVID-19 infection varied significantly across the whole cohort. With the exception of parkinsonism; Guillain-Barré syndrome; nerve root, nerve, and plexus disorder; encephalitis, most outcomes had HRs that were considerably more than 1 following 6 months, but their times to equal incidence and risk scopes differed substantially.

Following 1-2 months, the risks of prevalent psychiatric illnesses reverted to baseline (anxiety ailments at 58 days and mood ailments at 43 days), reaching an overall prevalence that was comparable to the matched comparison arm (anxiety disorders at 417 days, mood disorders at 457 days). At the conclusion of the 2-year follow-up period, the chances of seizures/epilepsy, psychotic illnesses, dementia, and cognitive deficiency (often known as "brain fog") remained elevated.

Children's post-SARS-CoV-2 infection risk trajectories were different from those of adults. In the six months following SARS-CoV-2 disease, children were not at an elevated risk of anxiety (1.00 [0.94-1.06]) or mood diseases (HR 1.02). However, they were at a raised risk of seizures/epilepsy, psychotic diseases, nerve, nerve root, and plexus diseases, ischaemic stroke, intracranial hemorrhage, insomnia, and cognitive impairment (HRs ranging from 1·20 [1·09-1·33] to 2·16 [1·46-3·19]).

Compared to adults, children with cognitive decline had a limited amount of time to equal occurrence (491 days) and a limited risk horizon (75 days). In all cohorts, a sizable number of older persons who were given a psychiatric or neurological diagnosis, particularly those with  seizures/epilepsy, dementia, later passed away. Prior to and immediately following the appearance of the alpha variants, risk profiles were comparable (n = 47 675 in each group).

Magnified risks of anxiety disorders, insomnia, cognitive impairment, seizures/epilepsy, and ischemic stroke were noted immediately after (vs immediately before) the introduction of the delta variant (n=44 835 in each cohort). These risks were further accompanied by an increased mortality rate. In the case of Omicron (n=39 845 in each cohort), a reduced mortality rate was noted than just before the variant emerged. However, the risks of psychiatric and neurological sequelae were the same.

As found, the elevated prevalence of anxiety and mood disorders was momentary. Furthermore, there was no general excess of these diagnoses in comparison with other respiratory illnesses. The elevated risks of seizures/epilepsy, cognitive impairment, dementia, and psychotic illness remained throughout. Different pathogenesis for these outcomes may be implied by the divergent trajectories. Compared to older adults and adults, children display a more benign overall profile of psychiatric risks. However, it is worrying that they continue to have a greater risk of certain disorders.

The same psychiatric and neurological outcomes during the omicron and delta waves suggest that even with variants that are less severe in other ways, the burden on the medical care system may persist. These findings are important for comprehending the risks of psychiatric and neurological diseases at the individual and population levels following COVID-19 infection and can guide the responses to those risks.