Talking is one of the most effective and cathartic ways to take the edge off negative emotions, although this is beyond the reach of verbally impaired youngsters, Gibson said. Verbal therapy helps, but this was unavailable at the height of the pandemic.

Minimally verbal children, as a result, may inadvertently resort to tantrums, outrageous behavior, or aggression to vent their inner fear and anxiety, Gibson said. "Some had spells of a meltdown when their needs of (communicating their negativities) weren't met."

"It's not surprising that children with speech problems go through the roof as they lose their grip on the festering stress because behavior is their form of communication", said Adam Boddison, chief executive of the United Kingdom's National Association for Special Educational Needs.

For children with sensory issues — difficulty in processing things like light, sound, smell, touch and other essential sensations — a subtle change in routine could become a stressor and spark a chain of dramatic behavior, added Gibson.

The lack of peer models in school and their frustration about repeated failures in online lessons can sabotage their confidence and motivation, causing aversion to studying or forcing them to drop out of classes. But this is merely a guess, as no studies on the long-term effects of disrupted school life routines have been done so far, she said.

But the sure thing is that "children learn best when they're in education and children being out of school is an emergency". "My prediction is that the risk of emotional and social difficulties as a long-term consequence would be much higher for this cohort of vulnerable students," Gibson said.

Individual differences

According to Gibson, students tend to navigate through their emotions together in school, where friends and peers are positively involved. The risks of being away from school for a long time include social withdrawal, apathy, anxiety from being friendless and, at worst, depression.

Boddison underscores the element of "individual differences" when it comes to the pandemic's effect on special-needs children.

The impacts are quite mixed, depending on the mental condition of different children, she said. For those with attention deficit disorder, for instance, the effects are more likely to be damaging, while for those socially struggling, such as the autistic, they might see remote learning at home as good, she explained. However, the latter may find it tough to return to school when the restrictions are lifted.

Jack Lee King-ngon, 15, who's autistic, is on the other side of the fence. He likes learning from home. "Studying in school is a waste of time for him. His mind wandered, and he fiddled with pens in class. He cringed at asking for a favor, so he came home with nothing every day," said his mother, Peacher Poon. "Online learning allows me to be his in-class assistant. He seems to realize that study is not others' affairs."

Poon said she has tried all sorts of therapies, including occupational therapy, craniosacral therapy, speech therapy, hydrotherapy, music therapy and acupuncture on her son, just to "wake him up".