I believe the article rightly addresses that there are multiple causes for sleep issues and that many are likely the result of stress from the pandemic. But they've noticed accute issues specifically in patients known to have tested positive fir COVID. From TFA:
> In recent months, however, Salas has watched a more curious pattern emerge. Many people’s sleep continues to be disrupted by predictable pandemic anxieties. But more perplexing symptoms have been arising specifically among people who have recovered from COVID-19. “We’re seeing referrals from doctors because the disease itself affects the nervous system,” she says. After recovering, people report changes in attention, debilitating headaches, brain fog, muscular weakness, and, perhaps most commonly, insomnia.
There is a contingent of HN posters who are primed to blame a lot of bad effects on "the lockdown." Frankly, I was one of them 8 months ago when there was actually a lockdown, but at least in most places in the USA there really hasn't been anything I could reasonably describe as a "lockdown" since early Summer. Mask mandates, and limits on how specific businesses can operate, sure, but nothing like the draconian shelter-in-place orders we saw in the spring.
I can say from firsthand experience that my families mental health is severely compromised at this point, but unfortunately none of it could be solved by less restrictive laws. It's all related to the pandemic and the choices we've had to make to reduce our chances of getting infected and passing that virus on to other people who have higher risks of dying.