The effects of COVID-19 infection on working memory: a systematic review

Abstract

Background

Studies demonstrate that people who have been infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, have experienced cognitive dysfunction, including working memory impairment, executive dysfunction, and decreased concentration. This review aimed to explore the incidence of working memory impairment and possible concomitant symptoms in the acute phase (< 3 months) and chronic phase (> 6 months) of COVID-19.

Methods

We conducted a systematic review of the following databases for inception: MEDLINE via Pub Med, Cochrane EMBASE, and Web of Science electronic databases. The search strategy was comprised of all the observational studies with COVID-19 patients confirmed by PCR or serology who were infected by SARS-CoV-2 with no previous cognitive impairment. This review protocol was recorded on PROSPERO with registration number CRD 42023413454.

Results

A total of 16 studies from 502 retrieved articles were included. COVID-19 could cause a decline in working memory ability, the results showed that 22.5–55% of the people suffered from working memory impairment in the acute phase (< 3 months) of COVID-19, at 6 months after SARS-CoV2 infection, the impairment of working memory caused by COVID-19 still existed, the prevalence was about 6.2–10%, and 41.1% of the patients had a slight decrease in working memory or a negative change in the boundary value. Moreover, concomitant symptoms could persist for a long time. To some extent, the performance of working memory was affected by age, the time after infection, and the severity of infection (β = −.132, p <.001; β = .098, p <.001; β = .075, p = .003). The mechanism of working memory impairment after infection was mainly focused on the aspects of neuroinflammation and the nerve invasiveness of the virus; at the same time, we also noticed some changes of the brain parenchymal structure.

Conclusion

COVID-19 can cause a decline in working memory ability, accompanied by neurological symptoms. However, there is a lack of studies to identify the structural and functional changes in specific brain regions that relate to the impaired working memory.

Keywords:

• COVID-19
• SARS-CoV-2
• working memory impairment
• cognitive dysfunction

Transparency

Declaration of funding

Shan Jiang received funding from the National High Level Hospital Clinical Research Funding (2023-NHLHCRF-YSPY-01 and ZRJY2021-BJ04) as research grant funding and from the Elite Medical Professionals Project of China-Japan Friendship Hospital (NO. ZRJY2021-BJ04). We also acknowledge the Youth Fund of the National Natural Science Foundation of China (81902294) from Xi Lu.

Declaration of financial/other relationships

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

Conceptualization: Xi Lu, Shan Jiang. Funding Acquisition: Shan Jiang and Xi Lu. Investigation: RuiDong Ge, Ming Zhen Li. Methodology: Min Li. Supervision: Shan Jiang. Visualization: Rui Cui, Bei Yao Gao. Writing- Original Draft: Rui Cui. Preparation: Rui Cui, Bei Yao Gao.

All authors were involved in critical revision of the manuscript for important intellectual content.

Acknowledgements

The authors acknowledge that a British native provided English editing.

Data availability statement

Data available on request from the authors.