Since your concern is for his mental health and clearly not a selfish desire to get his next game right now, shouldn’t you be advocating for him to get a therapist and not a publisher?
Sure seems like taking some time off with guidance from a doctor would help him the most personally, which again, is clearly your main concern.
Should working code even be part of an interview? Seems like a situation rife with abuse.
Need free contractors? Just put your code issues up as a 4hr take home interview test.