The Most Common Long COVID Symptoms That Linger Months After Infection

Chronic neuropsychiatric symptoms, known as “long COVID”, may follow COVID-19 infection, including anxiety, depression, worsened cognitive status, and impairments in taste and smell, according to study findings published in Brain, Behavior, & Immunity – Health.

Researchers conducted a single-center, prospective, closed cohort study the COVID-19 Neurological and Molecular Prospective Cohort Study in Georgia (CONGA) in the United States, and recruited 200 patients (mean age, 44.6 years; 64.5% women) a minimum of 4 weeks following confirmed COVID-19 infection. Nearly 40% of participants were Black and 7% were hospitalized because of COVID-19. The control cohort consisted of 342 patients participating in the Georgia Cardiovascular Twin Study or the Georgia Stress and Heart study from April 30, 2019 to July 7, 2021, which excluded anyone who tested positive for or self-reported COVID-19.

Researchers obtained pertinent data from anthropometric measurements, blood tests, a complete neurological examination, assessments for cognitive status, smell, and taste, and self-reported questionnaires about mood and COVID-19 symptoms. Specific assessments included the Montreal Cognitive Assessment (MoCA), the National Institutes of Health Toolbox (NIH-TB), the University of Pennsylvania Smell Identification Test (UPSIT), the Waterless Empirical Taste Test (WETT), the Patient Health Questionnaire-9 (PHQ-9), and the Generalized Anxiety Disorder-7 (GAD-7).

The most prevalent COVID-19 symptoms included fatigue (68.5%), headache (66.5%), olfactory changes (54.5%), and gustatory changes (54%). Confusion (21%) occurred less commonly.

The results of the questionnaires and assessments were as follows:

• Per the PHQ-9, 25% of 196 patients had depression.
• Per the GAD-7, 18% of 195 patients had anxiety.
• Per the MoCA, 47% of 191 patients had mild cognitive impairment.
• Per the NIH-TB, 30% of 196 patients had impaired vocabulary and 32% had impaired working memory.
• Per the UPSIT, 29.9% of 164 patients had impaired olfaction.
• Per the WETT, 29.6% of 159 patients had impaired taste.

Compared with the control cohort, patients in the post-COVID-19 cohort scored lower average percentiles on the working memory portion of the NIH-TB — both the overall COVID cohort (52.3 vs 43.9; P <.001) and in patients younger than 50 (52.3 vs 43.4; P <.001) years of age. The percentage of patients with working memory did not differ between groups.

“Our results support the growing evidence that there are chronic neuropsychiatric symptoms following COVID-19 infection,” the researchers stated. “Our results suggest that self-reported neurologic symptoms do not appear to correlate with associated quantitative dysfunction, emphasizing the importance of quantitative measurements in the complete assessment of deficits.”

Study limitations include lack of in-person administration of the smell and taste assessments due to COVID restrictions at the time of the study, the possibility of COVID infection in the control group although steps were taken to minimize this factor, and the possibility of intrinsic differences in the patients who sought out COVID testing from the general population. Additionally, the results of this study may not be generalizable outside of the study’s single-center geographic location and may not apply to hospitalized COVID patients.

Disclosure: This research was supported by the National Institute of Neurological Disorders and Stroke and the TR Reddy Family Fund. Please see the original reference for a full list of disclosures.