Long COVID ‘Brain Fog’ Confounds Doctors, but New Research Offers Hope
James C. Jackson, PsyD, a licensed psychologist specializing in neuropsychology and rehabilitation, at Vanderbilt University School of Medicine and author of a new book, Clearing the Fog: From Surviving to Thriving With Long COVID ? A Practical Guide, reports in Medscape July, 2023 : “There’s not a lot of imprecision in the term (brain fog) because it might mean different things to different patients,”
Jackson, who began treating [a patient] in February 2023, said that it makes more sense to call brain fog a brain impairment or an acquired brain injury (ABI) because it doesn’t occur gradually. COVID damages the brain and causes injury. For those with long COVID who were previously in the intensive care unit and may have undergone ventilation, hypoxic brain injury may result from the lack of oxygen to the brain.
An April 2022 study published in the journal Nature found strong evidence that SARS-CoV-2 infection may cause brain-related abnormalities, for example, a reduction in gray matter in certain parts of the brain, including the prefrontal cortex, hypothalamus, and amygdala.
Additionally, white matter, which is found deeper in the brain and is responsible for the exchange of information between different parts of the brain, may also be at risk of damage as a result of the virus, according to a November 2022 study published in the journal SN Comprehensive Clinical Medicine.“
Thus, new data suggest that long COVID is associated with inflammation and both reduced volume of several brain structures and decreases in white matter. These data suggest several novel approaches to therapy that require further study. One is low dose lithium which both increases gray matter volume and white matter integrity. Lithium also has some antiviral properties. This could be combined with anti-inflammatories that could be bought over the counter such as N-acetylcysteine (NAC), acetyl-L-carnitine, and celecoxib.
Note of caution. This is only an untested hypothesis and would need to be discussed with one’s physician before any of these options are considered.
Translocator Protein Levels in Brain Predict Response to Anti-Inflammatory Celecoxib in Major Depressive Disorder
Gliosis describes changes in glia that result from damage to the central nervous system. Researchers can use PET scans (positron emission tomography) to measure the extent of gliosis in the brain. But a new study explored whether these PET scans could instead be used to determine who might respond to a given medication.
Researcher Sophia Attwells and colleagues reported in the journal Biological Psychiatry in 2020 that people with high levels of translocator protein (TSPO), a measure of gliosis and inflammation, had a better antidepressant response to the anti-inflammatory drug celecoxib than patients who started out with lower levels of TSPO.
The study participants, who had treatment-resistant depression, all received 200mg of the anti-inflammatory drug celecoxib twice/day for eight weeks on an open (non-blind) basis. Before they began taking celecoxib, the participants received PET scans to measure translocator protein total distribution volume (TSPO VT) in the prefrontal cortex and the anterior cingulate cortex.
Patients with high levels of TSPO showed greater reductions in depression ratings over the course of the study than those with normal levels of TSPO at baseline.
Attwells and colleagues conclude that “this personalized medicine approach of matching a marker of gliosis to [an anti-inflammatory treatment] …should be applied in early development of novel therapeutics, in particular for [treatment-resistant depression].”
Editor’s Note: These findings are of considerable importance, as they are among the first to indicate that measures of inflammation may predict response to an anti-inflammatory medication such as celecoxib. In a 2013 article in the journal JAMA Psychiatry, Charles L. Raison and colleagues reported that patients with high levels of the peripheral inflammatory marker CRP saw marked improvement in their depression when they received the anti-inflammatory treatment infliximab while those with lower or normal levels of inflammation actually worsened.
Inflammation Associated with Cognitive Deficits
At the 2019 meeting of the International Society for Bipolar Disorders, researcher Katherine E. Burdick and colleagues at Brigham and Women’s Hospital and Harvard Medical School reported that in 240 patients with bipolar disorder who were not currently having a manic or depressive episode, markers of inflammation were associated with cognitive deficits.
Inflammation was associated with cognitive deficits in general, and there were also some relationships between specific inflammatory markers and types of cognitive processing. They found that the inflammatory markers TNF-alpha, TNFR1, and TNFR2 influenced cognitive flexibility. The inflammatory marker VEGF influenced reward processing, while IL-6/IL-6r influenced spatial processing. IL-1beta and IL-1RA influenced social cognition.
Burdick and colleagues found it was important to include both primary and secondary mediators of inflammation in their research “as the effects of the primary pro-inflammatory cytokines can be blocked by a number of decoy receptors and soluble antagonists.” Elevations in these can provide additional information about the function of the immune system.
Editor’s Note: Targeting inflammation with the anti-inflammatory treatments minocycline and celecoxib has been shown to improve depression. Now the role of anti-inflammatory drugs in improving cognition deserves further attention.
Arthritis Drug Celecoxib May Improve Bipolar Depression When Paired with Escitalopram
A new study suggests that for people with bipolar depression, the anti-inflammatory drug celecoxib (Celebrex), typically used to treat arthritis, can boost the effectiveness of the antidepressant escitalopram (Lexapro).
In the 8-week study by researcher Angelos Halaris and colleagues, adults with bipolar depression were randomly assigned to one of two groups. The first group received the selective-serotonin reuptake inhibitor (SSRI) antidepressant escitalopram plus celecoxib to target inflammation. The second group received just the antidepressant escitalopram and a placebo.
By the end of the study, 78% of the group taking the anti-arthritis drug had seen major improvement in their depression, with 63% reporting that it had lifted completely. Meanwhile in the placebo group, only 45% reported major improvement, and 10% reported remission.
The group that received celecoxib with their escitalopram also began seeing improvement within one week of beginning treatment, instead of after four to six weeks, which is typical of antidepressant treatment.
Researchers think depression creates an immune response leading to chronic inflammation, which can upset the balance of neurotransmitters in the brain and make antidepressants less effective. Halaris suggests that reducing this inflammation with a drug like celecoxib can make antidepressants more effective.
The research was presented at the Fifth International Congress on Psychiatry and the Neurosciences and has not yet been published.
Preliminary Evidence That Anti-Inflammatory Celecoxib Helps in Bipolar Depression
A study currently in progress indicates that the anti-inflammatory COX-2 inhibitor celecoxib (better known as the arthritis treatment Celebrex) may aid in the treatment of bipolar depression. In a panel session on inflammation at the 2015 meeting of the Society of Biological Psychiatry, researcher Angelos Halaris reported results from the first 26 participants.
Participants were taking mood stabilizers for bipolar disorder and became depressed. They received either 20mg/day of the selective serotonin reuptake inhibitor antidepressant escitalopram (Lexapro) plus either 200mg twice a day of celecoxib or placebo for a total of eight weeks. Those participants who received celecoxib showed greater and more rapid reductions in depression symptoms than those who received placebo.
The study will continue, and Halaris and colleagues will also observe whether measures of inflammation in patients’ blood are correlated with the patients’ responsiveness to the combined treatment with escitalopram and celecoxib.
Anti-inflammatory Celecoxib Improved Depression When Added to Escitalopram
Research has previously shown a link between stress, inflammation, and mood diorders. Anti-inflammatory treatments are now being explored for depression. In an abstract presented at the 2013 meeting of the Society of Biological Psychiatry, Nadia Alvi et al. reported that the commonly used anti-inflammatory COX-2 inhibitor celecoxib (Celebrex) showed better antidepressant effects than placebo when added to the selective serotonin reuptake inhibitor (SSRI) antidepressant escitalopram (Lexapro) in an 8-week study.
While this research has not yet been peer-reviewed, it can be found in the 2013 convention supplement (9S) to the journal Biological Psychiatry as abstract #661.
Editor’s Note: These data are consistent with an emerging literature that shows there are increases in signs of inflammation in both unipolar and bipolar depression. It remains to be determined whether those patients whose blood shows markers of inflammation (such as increases in C-reactive protein (CRP), interleukins 1 and 6, and TNF-alpha) are more likely to respond to anti-inflammatory treatment than patients in general.