New Delhi: Severe Covid-19 is linked to an increase in the risk of long-term adverse mental health effects, according to a new study published in The Lancet Public Health.


The study found that non-hospitalised patients with a SARS-CoV-2 infection were more likely to experience depressive symptoms up to 16 months after diagnosis compared to those never infected. Higher rates of depression and anxiety were observed in patients who were hospitalised for seven days or more, compared to people who were diagnosed with SARS-CoV-2 infection, but never bedridden.


For non-hospitalised patients with Covid-19, symptoms of depression and anxiety mostly subsided within two months, according to the study. Over the 16-month study period, patients who were bedridden for seven days or more remained at increased risk of depression and anxiety.


Social distancing requirements and a general uncertainty during the pandemic have taken a toll on people’s mental health. Previous studies have examined adverse mental health effects for up to six months after a Covid-19 diagnosis. However, not much is known about the long-term mental health effects beyond six months, particularly for non-hospitalised patients with varying degrees of illness severity.


What Mental Health Impacts Did The Researchers Observe?


The researchers of the study observed symptom-prevalence of depression, anxiety, Covid-19 related distress, and poor sleep quality among people with and without a diagnosis of Covid-19 from zero to 16 months, in order to capture long-term mental health impacts. The mean follow-up period was 5.65 months. 


The researchers drew upon data from seven cohorts across Denmark, Estonia, Iceland, Norway, Sweden, and the United Kingdom, as part of the study. 


As many as  2,47,249 were included in the study. Of these, 9,979 were diagnosed with Covid-19 between February 2020 and August 2021, accounting for four per cent of the participants. 


Patients With Covid-19 vs Individuals Not Diagnosed


The researchers found that participants diagnosed with Covid-19 had a higher prevalence of depression and poorer sleep quality compared to individuals who were never diagnosed. According to the study, 20.2 per cent of participants diagnosed with Covid-19 experienced symptoms of depression, while 11.3 per cent of the participants who were never diagnosed experienced these symptoms. 


Poor sleep quality was experienced by 29.4 per cent of participants diagnosed with Covid-19, and  by 23.8 per cent of participants who were never diagnosed.


When the researchers considered the rates of anxiety or Covid-related distress in participants with or without Covid-19. They observed no overall differences. 


Participants who were diagnosed with Covid-19, but never bedridden due to the disease, were less likely to experience symptoms of depression and anxiety, compared to those who were not diagnosed, according to the study.


One explanation for this is that the return to normal lives is a relief for these individuals while those still not infected are still anxious about the risk of infection and burdened by social isolation, the authors noted in the study.


The researchers observed a clear reduction of some mental health symptoms such as depression and Covid-related distress with time. According to the study, longer time bedridden was consistently associated with a higher prevalence of mental health effects. 


Patients who were bedridden for seven days or more continued to be 50 to 60 per cent more likely to experience higher depression and anxiety compared to people never infected during the 16-month study period. 


What Do The Researchers Say?


According to a statement issued by The Lancet, study author Professor Unnur Anna Valdimarsdóttir said that the new study is among the first to explore mental health symptoms after a serious COVID-19 illness in the general population up to 16 months after diagnosis. She said that it suggests that mental health effects are not equal for all Covid-19 patients and that time spent bedridden is a key factor in determining the severity of the impacts on mental health. 


Valdimarsdóttir further said that as the world enters the third year of the pandemic, increased clinical vigilance of adverse mental health among the proportion of patients with a severe acute disease of Covid-19 and follow-up studies beyond the first year after infections are critical to ensure timely access to care.


The authors noted in the study that the quicker recovery of physical Covid-19 symptoms may explain in part why mental health symptoms decline at a similar rate for those with a mild infection. 


Certain patients with severe Covid-19 often experience inflammation. This has previously been linked to chronic mental health effects, particularly depression.


Ingibjörg Magnúsdóttir, who co-authored the study, said that the higher occurrence of depression and anxiety among patients with Covid-19 who spent seven days or longer bedridden could be due to a combination of worrying about long-term health effects as well as the persistence of physical long COVID symptoms well beyond the illness that limit social contact and may result in a sense of helplessness.  Magnúsdóttir further said that equally, inflammatory responses among patients with a severe diagnosis may contribute to more persistent mental health symptoms. 


“In contrast, the fact that individuals with a mild COVID-19 infection can return to normal lives sooner and only experience a benign infection likely contributes to the lower risk of negative mental health effects we observed,” the statement quoted the author as saying.


The authors noted several limitations in the study, including the fact that the analysis reflects self-reported data of Covid-19 diagnosis and mental health effects, which are interrelated to some extent. The authors noted that most of the comparison group responded between April and June 2020, and responses from Covid-19 patients were accumulated between April 2020 and August 2021, which may have led to varying degrees of pandemic uncertainty that may have influenced the reporting of symptoms.