Tim Crow
Encyclopedia
Tim Crow is a British
psychiatrist
and researcher from Oxford. Much of his research is related to the causes of schizophrenia
. He also has an interest in neurology
and the evolutionary theory. He is the Honorary Director of the Prince of Wales International Centre for Research into Schizophrenia and Depression. He qualified at the Royal London Hospital
in 1964 and obtained a PhD
at the University of Aberdeen
, Scotland
, in 1970. He is a fellow
of the Royal Colleges of Physicians and Psychiatrists and the Academy of Medical Sciences
. Crow was for twenty years Head of the Division of Psychiatry of the edical Research Council (UK)|Medical Research Council] (MRC)] Clinical Research Centre at Northwick Park Hospital
and then a member of the External Scientific staff of the MRC in Oxford
.
and manic-depressive psychosis, these disorders are common, affecting around 2% of the population in the course of a lifetime.
In the first CT scan study in 1976 Crow and colleagues at Northwick Park demonstrated that there are structural changes (e.g. a degree of enlargement of the cerebral ventricles) in individuals who have suffered from schizophrenia. Much subsequent work with MRI scans and in post-mortem brain studies has confirmed this and suggests that the changes are in the cerebral cortex
and particularly are related to the subtle asymmetries that are characteristic of the human cortex.
What is the origin of these changes? In earlier work Crow considered but was able to rule out a viral causation. There is a genetic component but its nature has been obscure. Crow is known for his suggestion that schizophrenia is a widespread genetic anomaly which arose quite recently in human evolution. He believes that it arose with the evolution of language and that the two are linked. In his argument, he says that schizophrenia is associated with atypical patterns of lateralization - which is the differential functioning of the left and right cerebral hemispheres. Crow’s particular recent contribution has been the proposal that the origins of the psychoses relate particularly to those characteristics (e.g. cerebral asymmetry) that are associated with the specifically human capacity for language. This leads to a theory of the origin of psychotic symptoms – that they are associated with deviations in the subtle asymmetries of development of the cortex, and that the symptoms arise as confusions between thought and speech and through the abnormal attachment of meaning to perceived speech – and to its genetic basis in the change that led to the evolution of Homo sapiens as a species.
In an article published in 1977, Crow compared three drugs (fluphenazine
, chlorpromazine
, thioridazine
) with different tendencies to produce side effects, and was able to trace some of the anatomy of schizophrenia as well as shedding some light on what the differences between the drugs may mean. All three drugs are effective in controlling schizophrenic symptoms, but fluphenazine often causes motor side effects while chlorpromazine does less so, and thioridazine never does.
In 1980s, Crow published an article to the public that was known as a breakthrough in the field of research on schizophrenia. Crow focused on the classification of the symptoms of the disease instead of focusing on patients. Crow later introduced two syndromes of schizophrenia, one that is based on positive symptoms and the other on negative symptoms. These two syndromes are represented below as described by Crow:
) that has changed in the course of hominid evolution and may have played a particular role in the development of the cerebral cortex, and the evolution of language and the origins of psychosis.
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
psychiatrist
Psychiatrist
A psychiatrist is a physician who specializes in the diagnosis and treatment of mental disorders. All psychiatrists are trained in diagnostic evaluation and in psychotherapy...
and researcher from Oxford. Much of his research is related to the causes of schizophrenia
Schizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
. He also has an interest in neurology
Neurology
Neurology is a medical specialty dealing with disorders of the nervous system. Specifically, it deals with the diagnosis and treatment of all categories of disease involving the central, peripheral, and autonomic nervous systems, including their coverings, blood vessels, and all effector tissue,...
and the evolutionary theory. He is the Honorary Director of the Prince of Wales International Centre for Research into Schizophrenia and Depression. He qualified at the Royal London Hospital
Royal London Hospital
The Royal London Hospital was founded in September 1740 and was originally named The London Infirmary. The name changed to The London Hospital in 1748 and then to The Royal London Hospital on its 250th anniversary in 1990. The first patients were treated at a house in Featherstone Street,...
in 1964 and obtained a PhD
Doctor of Philosophy
Doctor of Philosophy, abbreviated as Ph.D., PhD, D.Phil., or DPhil , in English-speaking countries, is a postgraduate academic degree awarded by universities...
at the University of Aberdeen
University of Aberdeen
The University of Aberdeen, an ancient university founded in 1495, in Aberdeen, Scotland, is a British university. It is the third oldest university in Scotland, and the fifth oldest in the United Kingdom and wider English-speaking world...
, Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
, in 1970. He is a fellow
Fellow
A fellow in the broadest sense is someone who is an equal or a comrade. The term fellow is also used to describe a person, particularly by those in the upper social classes. It is most often used in an academic context: a fellow is often part of an elite group of learned people who are awarded...
of the Royal Colleges of Physicians and Psychiatrists and the Academy of Medical Sciences
Academy of Medical Sciences
The Academy of Medical Sciences is the United Kingdom's national academy of medical sciences. It was established in 1998 on the recommendation of a group that was chaired by Michael Atiyah. Its president is John Irving Bell....
. Crow was for twenty years Head of the Division of Psychiatry of the edical Research Council (UK)|Medical Research Council] (MRC)] Clinical Research Centre at Northwick Park Hospital
Northwick Park Hospital
Northwick Park Hospital is a large hospital in the northwest corner of the London Borough of Brent in Greater London, England.-Hospital role:...
and then a member of the External Scientific staff of the MRC in Oxford
Oxford
The city of Oxford is the county town of Oxfordshire, England. The city, made prominent by its medieval university, has a population of just under 165,000, with 153,900 living within the district boundary. It lies about 50 miles north-west of London. The rivers Cherwell and Thames run through...
.
Psychosis and schizophrenia
Crow’s long term research interests are in the nature and causation of the major psychoses. These illnesses are characterised by the presence of delusions and hallucinations and disorders of thinking and generally have an onset in early and middle adult life. Encompassing schizophreniaSchizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
and manic-depressive psychosis, these disorders are common, affecting around 2% of the population in the course of a lifetime.
In the first CT scan study in 1976 Crow and colleagues at Northwick Park demonstrated that there are structural changes (e.g. a degree of enlargement of the cerebral ventricles) in individuals who have suffered from schizophrenia. Much subsequent work with MRI scans and in post-mortem brain studies has confirmed this and suggests that the changes are in the cerebral cortex
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...
and particularly are related to the subtle asymmetries that are characteristic of the human cortex.
What is the origin of these changes? In earlier work Crow considered but was able to rule out a viral causation. There is a genetic component but its nature has been obscure. Crow is known for his suggestion that schizophrenia is a widespread genetic anomaly which arose quite recently in human evolution. He believes that it arose with the evolution of language and that the two are linked. In his argument, he says that schizophrenia is associated with atypical patterns of lateralization - which is the differential functioning of the left and right cerebral hemispheres. Crow’s particular recent contribution has been the proposal that the origins of the psychoses relate particularly to those characteristics (e.g. cerebral asymmetry) that are associated with the specifically human capacity for language. This leads to a theory of the origin of psychotic symptoms – that they are associated with deviations in the subtle asymmetries of development of the cortex, and that the symptoms arise as confusions between thought and speech and through the abnormal attachment of meaning to perceived speech – and to its genetic basis in the change that led to the evolution of Homo sapiens as a species.
In an article published in 1977, Crow compared three drugs (fluphenazine
Fluphenazine
Fluphenazine is a typical antipsychotic drug used for the treatment of psychoses such as schizophrenia and acute manic phases of bipolar disorder. It belongs to the piperazine class of phenothiazines....
, chlorpromazine
Chlorpromazine
Chlorpromazine is a typical antipsychotic...
, thioridazine
Thioridazine
Thioridazine is a piperidine typical antipsychotic drug belonging to the phenothiazine drug group and was previously widely used in the treatment of schizophrenia and psychosis...
) with different tendencies to produce side effects, and was able to trace some of the anatomy of schizophrenia as well as shedding some light on what the differences between the drugs may mean. All three drugs are effective in controlling schizophrenic symptoms, but fluphenazine often causes motor side effects while chlorpromazine does less so, and thioridazine never does.
In 1980s, Crow published an article to the public that was known as a breakthrough in the field of research on schizophrenia. Crow focused on the classification of the symptoms of the disease instead of focusing on patients. Crow later introduced two syndromes of schizophrenia, one that is based on positive symptoms and the other on negative symptoms. These two syndromes are represented below as described by Crow:
| Features | Positive | Negative |
|---|---|---|
| Characteristic symptoms | Hallucinations, delusions, and thought disorder Thought disorder In psychiatry, thought disorder or formal thought disorder is a term used to describe incomprehensible language, either speech or writing, that is presumed to reflect thinking. There are different types... |
Poverty of speech, flattening of affect, and social withdrawal |
| State of illness | Acute | Chronic |
| Response to anti-psychotic drugs | Good | Poor |
| Intellectual impairment | Absent | Present |
| Pathological process | Increased dopamine receptors | Structural brain abnormalities |
Work in the Prince of Wales Centre
The work of the Prince of Wales Centre will focus on this theory through radiological investigations of brain structure in relation to the symptoms of psychosis, post-mortem studies of the nature of the change at a cellular level, and investigation of a gene (ProtocadherinXY) located on the X (PCDHX) and Y chromosomes (PCDHYPCDHY
PCDH11Y is a gene unique to human males which competes for the title of the "language gene." PCDH11Y is the gene for making Protocadherin 11Y, a protein that guides the development of nerve cells...
) that has changed in the course of hominid evolution and may have played a particular role in the development of the cerebral cortex, and the evolution of language and the origins of psychosis.
External links
- Professor Tim Crow, on the Prince of Wales International Centre for SANE Research Website
- Audio interview with Professor Tim Crow, by Basque journalist Edu Lartzanguren (2006)