Quite some years ago, a son of a friend of mine had a sports accident and suffered a femoral fracture. A lengthy immobility was demanded, and the recovery time was very bothersome in a myriad of ways. He went to school anyway, even though this necessitated special arrangements. It had not occurred to me then that kids really go to school with health conditions that allow sick leave from work to adults.
Nowadays, however, it is at least a weekly topic of discussion in my work whether or not an adolescent is too sick to go to school. But not at all from the viewpoint that s/he perhaps should have a rest because schoolwork would be too hard now or s/he cannot perform on her/his ordinary level. The discussion focuses on whether or not the school has a right to refuse taking the adolescent to the classes because of her/his (assumed) mental health condition that makes her/him harmful company to peers or a potential threat to school safety.
In some cases, sick leave from work and sick leave from school are about the same issue. For example, if you have a gastroenteritis and keep vomiting all day. But in many other occasions I don’t think we can talk about “school disability” parallel to work disability. Kids are not in the school to exchange their labour to salary. Going to school is an important normative developmental task. It is about learning academic and social competencies, it gives structure and meaning, and is an arena for rehearsing all kinds of skills that the children and adolescents will need in their future independent life.
I am not aware of any adolescent psychiatric disorder that would get better by spending unstructured and unsupervised time alone home or hanging around in antisocial activities. Going to school and being involved is itself a part of remedy, not something you will do after getting healthy again. Psychiatric disorders tend to be long-term and have better and worse periods. I constantly notice that many professionals working with adolescents seem to assume that psychiatric treatment is a trick that is done somewhere else (perhaps in a hospital), and then the adolescent is returned to school “fixed”. But most of psychiatric treatment takes place in form of repeated appointments in an outpatient clinic, and most of the time the patient is living his/her life in the home and going to school, work, hobbies etc. School and treatment need to support the adolescent at the same time.
Particularly concerns are often expressed about “school disability” in relation to adolescents who seem to be adopting an antisocial and violence admiring identity. Surely someone else should do something about such a kid. Psychiatrists should lock him up in a ward and medicate and use magic talk. Child welfare should place him someplace far from antisocial peers and negative family influences. Police should prevent him from committing crimes. But being preventively locked up somewhere far for over the adolescent years (which is not possible) would also mean preventing the adolescent from completing major developmental tasks that in our society take place in the context of school. Sometimes an adolescent who appears to pose a threat does not have a treatable psychiatric condition nor a family background characterized with psychosocial problems. School, social and health authorities can see that the kid is not developing positively, but there is no specific cure. Then the only way is to support completing of normative developmental tasks, and for this, participating age-appropriate education is of outmost importance. Certainly, some adolescents will need such extensive support and special arrangements that it will be very expensive for the municipality. But not providing that support may be many times more expensive in the future.