Increase in ADHD following the pandemic: does SARS-CoV-2 play a role?
There is a new large, interesting study on this specific aspect, that in my opinion is worth some more discussion and particularly on a different perspective.
Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder characterized by persistent inattention and/or hyperactivity-impulsivity that interfere with functioning or development already at childhood. Individuals with ADHD are often challenged by executive dysfunction, including impairment in organizing, setting schedules, and emotion dysregulation such as lowered tolerance for frustration. ADHD is associated with a range of other psychiatric disorders across the life span and predisposes to marginalization from education and labor market.
Of note, several reports suggest an increase in attention-deficit/hyperactivity disorder (ADHD) symptoms during the COVID-19 pandemic. However, most studies are anecdotal and based on case reports or series. This nationwide study assessed new ADHD diagnoses and ADHD prevalence before and during the pandemic, from 2015 to 2022 in Finland. This is a very solid design as this longitudinal cohort study comprised the entire Finnish population. ADHD diagnoses and medication use were obtained from nationwide registers and assessed at 3 time points: in 2015 and before (2020) and after (2022) the pandemic. Data were analyzed from January 2015 to June 2022.
The cohort comprised 5 572 420 individuals (2 819 645 women [50.6%]). Lifetime prevalence of ADHD increased by 2.7-fold during 2015 to 2022; prevalence was 1.02% in 2015 (95% CI, 1.01%-1.03%), 1.80% in 2020 (95% CI, 1.79%-1.81%), and 2.76% in 2022 (95% CI, 2.75%-2.77%). Young men aged 13 to 20 years had the highest lifetime prevalence of 11.68% (95% CI, 11.56%-11.81%) in 2022. New ADHD diagnoses doubled during the pandemic, from 238 per 100 000 in 2020 to 477 per 100 000 in 2022. The pandemic-associated incremental increase in new diagnoses was 18.60% (95% CI, 16.47%-20.49%; 9482 per 50 897 cases). Young women aged 13 to 20 years had a 2.6-fold increase in new diagnoses during the pandemic, from 577 per 100 000 in 2020 to 1488 per 100 000 in 2022, and women aged 21 to 30 years had a 3.0-fold increase, from 361 per 100 000 to 1100 per 100 000. New diagnoses increased by 2.9-fold among those older than 55 years (from 5 per 100 000 to 13 per 100 000 in women and from 5 per 100 000 to 14 per 100 000 in men). Boys younger than 13 years had the highest absolute rate of new ADHD diagnoses in 2022 (1745 per 100 000), but boys and young men younger than 21 years did not show a significant incremental increase in new diagnoses. Lifetime prevalence of ADHD medication purchases was 0.57% (95% CI, 0.56%-0.58%) in 2015 (31 771 [55.62%] of those with ADHD diagnosis), 1.15% (95% CI, 1.14%-1.16%) in 2020 (64 034 [63.83%]), and 1.69% (95% CI 1.68%-1.70%) in 2022 (92 557 [61.43%]), respectively.
The conclusion of this study was that new ADHD diagnoses and ADHD prevalence showed significant increase in Finland during the pandemic. ADHD medication use did not increase in relation to ADHD diagnoses. These results highlight potential adverse outcomes of pandemic-associated changes in living conditions.
HOWEVER, WHAT WOULD BE THE PANDEMIC ASSOCIATED CHANGES IN LIVING CONDITIONS?
Historically, it is thought that changes in social, occupational, and learning environments, such as loss of routines, lack of face-to-face contacts outside of home, increased demand for online activity, excessive screen time and digital media use, and reduced physical exercise, contribute to the increase in ADHD symptoms in other populations. However, Twin studies suggest a substantial genetic risk component for ADHD with heritability estimates ranging between 77% and 88% and remaining stable throughout the life span. Established environmental risk factors include early life experiences such as maternal substance abuse during pregnancy, ischemic birth conditions, psychosocial deprivation, and emotional trauma.
Accoording to the authors, and many, adverse living conditions later in life, such as a pandemic lockdown, should have a limited association with new-onset ADHD in older adolescents and adults. Pandemic lockdown imposed a sudden increase to attention and executive behavioral demands, coupled with a lack of daily structures and reduced possibilities for physical exercise. These challenges in living conditions may have surfaced ADHD symptoms in individuals previously coping sufficiently in their daily life. In additions, several studies have reported a connection between increased screen time and inattentive symptoms. Restrictive measures due to the pandemic pushed people to remote studies or work, exposing many to the jungle of digital platforms, abundant screen time, and increased demands for concentration and self-direction.
So basically, according to the authors, only these social changes implemented during the pandemic have contributed substantially to the increase in ADHD diagnoses. This is interesting, considering that countries from Northern Europe, and therefore Finland as well, were those less restrictive during the pandemic.
THEREFORE, I AM VERY MUCH SURPRISED - AND PERPLEXED - THAT NOT EVEN A SENTENCE IN THE PAPER HAS AT LEAST SPECULATED THAT A NEW “ENVIRONMENTAL FACTOR”, SUCH AS THE PRESENCE OF A NEW VIRUS WITH NEUROTROPISM, MIGHT HAVE CONTRIBUTED.
If you know my blog, you know very well how Covid-19 can cause several long lasting neurocognitive problems. In the literature, also post-covid ADHD is clearly described (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10102822/).
I am surprised that authors are not even considering this as an hypothesis worth funding and research. This is shocking in my opinion. The aetiology of ADHD is still unknown, and so far links with infections are not yet ruled-out. Conversely, a clear link between ADHD and higher susceptibility to ifnections has been noted (https://www.sciencedirect.com/science/article/pii/S0890856722012436). How can we exclude taht a predisposition to react abnormally to specific infections, leading to ADHD symptoms, are not triggered by viral-like infections?
I am surprised, I strongly believe that this national Finnish study is very important, but it is too simple to link this increase in ADHD diagnosis to simple life-style changes.