Because the intellect, unlike the other powers of the mind such as sensation, imagination, etc, is entirely immaterial, a primary disorder of the intellect would be intrinsically immaterial, and might be thought of as a spiritual disorder of character, or a tendency to sin, or even demonic influence/possession.
That was part of the post “Ask the doctor: ID-friendly neurosurgeon talks about mental illness” at the Uncommon Descent blog.
This sort of thinking is part of why there is so much discrimination against people with mental illness. It denies that mental illness is an actual illness, and instead stigmatizes it as due to sin or demon possession.
The posters at the Uncommon Descent blog wants us to believe that they are presenting a scientific case for intelligent design. Yet they allow posts which put forth primitive ignorant beliefs.