Abstract
Brian Dean, Mental Health Research Institute, Melbourne, Australia:
I would first like to thank Dr McLaren for acknowledging the extensive nature of my recent review [1]. It would seem that Dr McLaren then goes on to conclude that my interpretation of the data in this review is without value. This is because I have made the ‘error of believing that any [physical] changes are necessarily primary [in causing the symptoms of mental illness] … [and this] will keep on happening because biological psychiatrists refuse to lift their heads from their microscopes to look at the larger issues’. Dr McLaren has put this argument previously [2], along with the argument that the ‘biopsychosocial model’ of psychiatry is of no value [3].
To most of us in medical research, science is an inclusive rather than exclusive exercise in attempting to improve the lifestyle of those with illness. As such, rather than simply refuting Dr McLaren's position that the answers to the causation of mental illness lie in the ‘mental’ rather than ‘biological’ state of the brain, it would seem better to assess where these two hypotheses may overlap. Dr McLaren rightly points out that the human brain is a complex organ, the function of which is dependent on complex interactive processes. The research I describe in my review is designed to understand how the components of the brain that allow it to carry out many of its function may be deranged in mental illness. It does not exclude the possibility that mental illness is due to a derangement of higher brain function. Like the great Australian neuroscientist, John Carew Eccles [4], Dr McLaren suggests that mental processes may affect the operational integrity of the brain. While this is an excellent working theory, there is a paucity of data on whether an abstract ‘mind’ exists and how it functions, let alone enough data to allow the study of its abnormalities in mental illness. Even despite this paucity of data, I do view research designed to understand the complex ‘mind/brain’ relationship [5] to be of value, even though the immediate benefits of such research are not clear. However, until this research generates some convincing and testable hypothesis as to the cause of mental illness, I believe there is also great value in continuing to study the structure of the human brain and how it may be altered in these illnesses. Surely, Dr McLaren would agree that all efforts must be made to reduce the burden that mental illness places on sufferers of those illnesses.
Those committed to a single point of view can take many statements out of context. Unfortunately, Dr McLaren is perhaps over-zealous in taking quotations from my review to support his position. For example, a quote he references back to my review is ‘… the dopamine hypothesis of schizophrenia still requires total validation…’ Dr McLaren states that this indicates an idea of ‘certainty which soars above mere detail’. Importantly, the sentence quoted actually states that ‘While the dopamine hypothesis of schizophrenia still requires total validation, studies using brain tissue obtained at autopsy and PET suggest there are changes in the functioning of the dopaminergic systems in subjects with schizophrenia’. The key word in the sentence being ‘suggest’, not a word associated with certainty. Dr McLaren also chooses to totally ignore my closing remark that the most important outcome from the acceptance of my hypothesis that presynaptic abnormalities are important in the pathology associated with schizophrenia would be to re-direct drug design programmes to targets other than postsynaptic receptors. Given the need to develop better drugs with which to treat schizophrenia, I would have thought even Dr McLaren would be in favour of ideas being developed and discussed in this important area of pharmacology.
In closing, I would like to correct another error made by Dr McLaren. I am not a psychiatrist, I am a biologist who chooses to use my expertise in attempting to understand the processes that precipitate schizophrenia. Unfortunately, I have not looked down a microscope in many years, but I have certainly looked away from whatever technology I am using in an attempt to appreciate and understand the views of others. Perhaps this would be a good ethos for the ‘mind over brainers’ to adopt when reading reviews of other areas within the broad horizons of psychiatric research.