Mr Kandel won the Nobel prize among many other awards. His reputation is safe and it is why he is a good example to talk about what he is about and as importantly what he is not.
Wikipedia has it that he is a "neuropsychiatrist". Neuropsychiatry is a "branch of medicine that deals with mental disorders attributable to diseases of the nervous system". Given what Mr Kandel is known for, it makes sense to call him a "neurospsychologist" because neuropsychology "studies the structure and function of the brain as they relate to specific psychological processes and behaviors."
Mr Kandel may have studied psychoanalysis but the work he is celebrated for did not deal with people, so he did not deal with mental disorders; the Wikipedia text is quite clear about this. By considering Mr Kandel as a neuropsychiatrist, it is implied that his work has a practical application to mental health while at most his work helps explain how memory works.
The work of Mr Kandel is important but it is a fallacy to call it psychiatry when it so obviously is not. It is a fallacy because it takes away from what psychiatry is about.