I've heard some people say that they think that psychiatric disorders are neurological disorders really. As our understanding of neurology increases psychiatric disorders will be revealed to be neurological disorders and so ultimately the distinction between psychiatry and neurology cannot be maintained.

People who attempt to hold onto the distinction sometimes say that psychiatric disorders are disorders of cognitive processes whereas neurological disorders are non-cognitive disorders of neural processes. Cortical blindness is a disorder of a paradigmatically cognitive process (vision), however, yet most peoples intuitions are that cortical blindness is neurological rather than psychiatric.

In the other direction the essential feature of Tourette's is tics where tics are a motor disturbance. Tourette's is considered to be psychiatric rather than neurological, however. One could attempt to characterise psychiatric disorders as disorders of volition (the will) but then the trouble is that lesion to the motor cortex can result in paralysis yet this is regarded as neurological rather than psychiatric.

What do people think?

Will the distinction between neurological and psychiatric disorders break down as our knowledge advances or are there grounds for a principled distinction?

I'm not sure...