Study. “Brain Fog” Caused by Long COVID Lowers IQ

People experiencing Long COVID have measurable memory and cognitive impairments equivalent to a difference of about six IQ points, a study led by a neuroscientist shows.

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People affected by Long COVID (Long COVID) have measurable memory and cognitive impairments equivalent to a difference of approximately six IQ points, according to a study cited by “The Guardian”. More precisely, the research shows that these patients have significant deficiencies in the performance of tasks involving memory, reasoning and executive function. The scientists say this showed that the “brain fog” had a quantifiable impact.

Professor Adam Hampshire, a cognitive neuroscience researcher at Imperial College London and first author of the study, said it was not at all clear what brain fog actually was. “As a symptom, it has been reported quite a bit, but what our study shows is that brain fog can be correlated with objectively measurable impairments. This is quite an important finding”the researcher confesses.

Last year, the Office for National Statistics estimated that around 2 million people in the UK were experiencing self-reported Long COVID. A previous review by Imperial College found that tens of thousands of people in England could have symptoms that lasted a year or more after infection.

The most recent study recruited more than 140,000 Britons. Between August and September 2022, participants were administered online cognitive tests designed to test memory, attention, reasoning and other aspects of brain function.

The ability to function is affected

Approximately 3.5% of the sample had symptoms that persisted after 12 weeks, and of these approximately two-thirds still had symptoms at the time of assessment. The analysis found small deficiencies that were still detectable a year or more after infection for those who had been infected and no longer had symptoms. The difference in test scores between those who had been infected and those who had not been infected was equivalent to about three IQ points if they had been given an IQ test. For an individual, this magnitude of change is unlikely to be noticeable, the scientists said, although some may have experienced more pronounced effects.

Those patients with unresolved symptoms, which persisted for more than 12 weeks, were found to have a greater deficit, equivalent to six IQ points. Dr Maxime Taquet, a psychiatrist and researcher at the University of Oxford, who was not involved in the study, said: “Even if cognitive impairments after COVID-19 are on average small in magnitude, a substantial minority of people have more significant impairments that are likely to affect their ability to work and function. Considering the scale of the pandemic and the number of people affected, this is particularly worrying”.

Overlaid with PTSD

Psychiatrist Gabriel Diaconu told “Adevărul” that, in his opinion, it is not the patients' IQ level that is most important in this equation of Long COVID. “Of course, we are talking about, among other things, problems with memory, concentration, sleep or appetite. I think we are dealing practically with an overlap of the Long COVID syndrome with PTSD (Post-traumatic stress disorder – Stres posttraumatic – ed.), because of the trauma of going through the disease. And here we are referring especially to those who were in a not so good condition after being infected. The good thing is that up to a point, at least partially, patients with Long COVID can recover. I say in part because I have noticed a worrying phenomenon. In a significant part of these patients, we are dealing with a brain that is less responsive to drugs, and therefore with lower treatment results. Percentage-wise, within a year of going through COVID and treatment, 15-20 percent of patients fully recover, but we also have 10-15 percent who make absolutely no progress. The rest of the patients make progress after the treatments, but without referring to a full recovery. I repeat, we are talking about an interval of one year”explained psychiatrist Gabriel Diaconu.

One million patients

He believes that it is possible that the manifestations of Long COVID differ depending on the time of infection, but says that there are no clear studies on this. “At the moment I don't know if all the strains of COVID have had the same effect on the brain, but it is certain that the neurological manifestations have fluctuated. At the same time, I am tempted to say that vaccinated people are safe from Long COVID, but we have no relevant studies in this regard. Anyway, it must be said that such manifestations of post-viral fatigue can also bring measles or even the flu”the doctor emphasized.

According to the researcher Octavian Jurma, at least one million Romanians are affected by Long COVID, i.e. problems of the respiratory system (dyspnea, persistent cough), the cardiovascular system (palpitations, chest pain, tachycardia), the neurological system (fatigue, headaches , “brain fog”- mental fog, sleep disorders, anxiety and depression) or the digestive system (diarrhea, abdominal pain, nausea and vomiting, loss of appetite). In addition, some people complain of muscle pain, joint pain, fatigue or muscle weakness. “It is important to note that the incidence of Long COVID is estimated to be between 5 and 20% and not everyone will experience all of the symptoms listed above. Often there are only 1 to 3 symptoms. The most common symptom reported in Long COVID is fatigue. And cardiovascular disorders are common, which is why physical exercise is not beneficial and not recommended for recovery in the case of COVID, on the contrary”Octavian Jurma posted.