Il give you a bit of my story as such, I had a breakdown when I was in secondary school. It was late 1980s early 90s and I ended up leaving at the end of the 4th year (transition year).
I was deeply depressed, I had been struggling during the summer between 2nd and 3rd year but in August before heading into the 3rd year,
I started collapsing on top of being depressed. It looked like I was fainting but I literally could be talking to someone and hit the floor mid-word.
Straight out like a light switch and would come on in about a minute, be dazed for a minute or 2 and back to normal then, when this had happened maybe 20-30 times a day I needed a long deep sleep which my body took wherever it was.
All my classmates had excellent 1st aid skills as recovery position was the 1st thing they/we learned in the class and they all probably had a turn at turning me and some of them protecting modesty etc. I would often end up with a pile of coats on top of me.
Between my depression which was to end up with my admittance to the local psychiatric hospital 8 times before I was 17 (when my friends were going into 5th year for context) out of the 168 days in the school calendar year,
I physically made it to school on 55 of them and of those 55 I was sent home on 38 separate days (we had agreed that I would try and keep going after each collapse if possible but after 4 collapses they would send me home) so basically I completed 17 full days of school.
The last couple of months of the school year I was on indefinite home study leave leading up to the then inter cert (that's going way back) but in consultation with my mum, school psychologist, psychiatrist, chairman of VEC board, GP and school principal who was very supportive, and myself.
it was decided that the inter cert exams would be too stressful pending I was able to get there in the first place and would be disruptive collapsing all the time.
It took until I was 35 for the reason for the collapsing to show itself fully, my depression is long standing and has been there since I was 13, I will be 43 in next few months.
Collapsing improved a bit as I took an upswing in mood (later known as mania) and I went back into 4th year as a TYO student. I was given somewhere to lie down and used it only as needed.
I wasn't allowed to do sports or PE due to the risks involved. I had a great TYO year although I had the downs and was still collapsing, towards the end of the school year I went with the school to represent them in France in an international drama festival with other 4th years.
I hit the ground up the Eiffel Tower and the Champs Elysee but although I was wrecked by night time I had the time of my life, great memories made which helped sustain me in the years that followed.
I made the decision to move out of RoI to the north of the border at the time I would have been going into 5th year, I thought I could get away from my illness (es) how naive I was - but live and learn.
I returned to education about 10 years later part-time in the north while working and applied for although I didn't end up taking it up in the end due to other circumstances BA Hons (level 8) so it wasn't a hold up overall not having the LC
So i left school in 1992 and they were able to accommodate me then support me so I see no reason why the school cant do the same or even better now for your DS