Since the 1970s in Denmark, children with learning disabilites of any kind have been incorporated as far as possible in normal schools, instead of being sent to "special schools." This worked fine in the 1970s when there was plenty of public money for training teachers to teach these children and teaching teachers how to incorporate them in "normal" classes.
Since the late 1980s public funding has decreased and children have generally speaking been allowed far more self-expression, which can easily be transformed into what formerly was called "bad behaviour".
Today, it is hard to deal with disruptive children, as by and large, schools cannot rely on parents to see the problem, or allow any disciplinary methods to be employed. Detention is a thing of the past, as is asking parents to teach their children good manners or consideration for others in their class.
So a climate has arisen of giving such children a diagnosis. Obviously conditions such as autismn, adhd, asperges syndrom, dislexia etc. do exist, but as a teacher I have long suspected that adhd and asperges are made worse if children are never told what to do, and what not to do - these children need boundaries, as do all children. Many teachers, like myself, do feel that many children are wrongly diagnosed with these conditions - -they are not true sufferers from them, but are children striving through bad behaviour to attract the attention that they are not receiving either from their parents or their teachers.
Neglected children have always "been naughty" in an attempt to draw much needed attention to themselves.