April 6 (UPI) -- More than one-third of people in the United States who survive COVID-19 develop a psychiatric or neurological condition related to the virus within six months of infection, an analysis published Tuesday by The Lancet found.
Among those with a psychiatric disorder related to the virus, anxiety was the most common, at 17% of patients, while 14% suffered from depression, the data showed.
Seven percent of patients who experienced neurological complications had a stroke while in intensive care and 2% were diagnosed with dementia within six months of becoming infected.
These diagnoses were more common in COVID-19 patients than in those with flu or respiratory tract infections over the same time period, suggesting a specific impact of the coronavirus on mental and brain health, researchers said.
"Although the individual risks for most disorders are small, the effect across the whole population may be substantial for health and social care systems," study co-author Dr. Paul Harrison said in a statement.
This is "due to the scale of the pandemic and [the fact] that many of these conditions are chronic," said Harrison, a professor of psychiatry at the University of Oxford in England.
For this study, Harrison and his colleagues reviewed the electronic health records of more than 236,000 COVID-19 patients from the United States age 10 years and older who were infected after Jan. 20, 2020, and still were alive on Dec. 13, 2020.
They compared rates of 14 neurological and psychiatric disorders among these patients with those of more than 106,000 people diagnosed with influenza and more than 236,000 people diagnosed with any respiratory tract infection.
Within six months of COVID-19 infection, 34% of patients developed a neurological or mental health disorder, the data showed.
For 13% of these people it was their first recorded neurological or psychiatric diagnosis.
In addition to anxiety and depression, 7% of those with psychiatric conditions were diagnosed with substance misuse disorders and 5% had insomnia.
The risk for a neurological or psychiatric diagnosis were greatest in, but not limited to, patients who had severe COVID-19.
While 34% of people infected developed these complications, that percentage was slightly higher, at 38%, among hospitalized patients and even higher, at 46%, in those in intensive care.
Similarly, 5% of patients hospitalized with COVID-19 were diagnosed with dementia, compared with 2% of the total study population.
Meanwhile, after taking into account underlying health characteristics, such as age, sex, ethnicity and pre-existing health conditions, there was an overall 44% greater risk for neurological and mental health diagnoses after COVID-19 than after flu, and a 16% greater risk after COVID-19 than with respiratory tract infections.
"Our results indicate that brain diseases and psychiatric disorders are more common after COVID-19 than after flu or other respiratory infections, even when patients are matched for other risk factors," study co-author Dr. Max Taquet said in a statement.
"We now need to see what happens beyond six months," said Taquet, a researcher in psychiatry at the University of Oxford.