Some can be improved with meditation. For example there is a roughly 60% comorbidity of ASD and ADHD and the ADHD portion can be improved with certain nonstimulant medications. Another example is that some disorders like psychosis and schizophrenia could pose harm that demands intervention.

I wouldn't put ADHD and psychosis in the same bucket.

Some is being different to various degrees(with having more problems to adjust to modern life without medication), the other is having a mental illness where most cannot perceive reality undistorted anymore.