Neurology, Psychiatry, and Neuroscience

To the Editor: I read with great interest the article by Dr. Martin concerning the future of psychiatry in relation to neurology and neuroscience. In the main, I agree with his analysis and with his predictions about the growing rapprochement among these three fields.

But the small differences are important, too, and I welcome this opportunity to make my own position clearer. The question comes down to this: if psychiatry and neurology have a strong common ground in brain science, then what distinguishes them? Why maintain any degree of separation between these two fields? What is the unique value of psychiatry? What does psychiatry bring to the table that neurology cannot be expected to provide?

The answer to all of these questions is psychiatry’s concern with subjectivity: how do people think, how do people feel, and how can we relate their cognitive and affective experiences to brain activity? Great progress has been made in this brain/mind domain in the past decade, almost all of it by psychiatrists using neuroscience as a source of data and/or models.

My own field, sleep and dream research, affords abundant examples. One of the most striking and relevant recent discoveries is that the localization of stroke lesions can be correlated with changes in dreaming. Mark Solms (1), a psychoanalytically oriented neuropsychologist, studied 300 cases of stroke and found that dreaming is suppressed and/or permanently eliminated by stroke damage to the parietal operculum or to frontal white matter. Now, these findings could have been made at any time, by any neurologist (including Sigmund Freud), but they were not. Why not? The reason is clear. Sleep and especially dreaming were not taken into account by neurology, but they were of great interest to psychiatry.

At exactly the same time that Solms was doing this work on brain-damage effects on dreaming, positron emission tomography (PET) imaging studies were revealing the intense activation of these same regions in REM sleep. The PET studies were performed by a neuroscientist (2), a neurologist (3), and a psychiatrist (4). This concatenation of expertise is exactly what Dr. Martin and I acknowledge and applaud. But who will carry this work forward by quantifying the subjective experience of dreaming so that its distinctive formal features can be linked to regional activation and inactivation of the brain?

My answer is that, because of their overriding interest in the mind, psychiatrists are likely to take the initiative in this effort. They may also, as Dr. Martin suggested, concern themselves more than neurologists with “functional” problems. I do not accept Dr. Martin’s distinction between functional and structural. For me, all conditions of the mind are based upon both structural and functional properties of the brain. That is why I coined the term “dynamic neurology” in reformulating the important aspects of theory regarding sleep and dream dissociation and disorders of thought and mood.

To ignore the important and mainstream contributions of psychiatry to resolution of the mind/brain question is to seriously underrate psychiatry. When Jonathan Leonard and I decided to title our book Out of Its Mind (5), we meant to chastise psychiatry, as much as neurology, for failing to create a psychology that could match progress in neuroscience. That task must remain at the top of the scientific agenda until it is successfully undertaken.

Now more than ever we need a scientific psychiatry as well as a closer tie to neuroscience and neurology. Dr. Martin is in a position to help build such a psychiatry, and I am eager to know how he plans to do so.