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Briefing Paper
SCHIZOPHRENIA AND MANIC-DEPRESSIVE DISORDER ARE DISEASES OF
THE BRAIN
It has been suspected for over a century that schizophrenia and
manic-depressive disorder (bipolar disorder) are diseases of the brain. In 1837,
Dr. W.A.F. Browne, the best-known English psychiatrist of his generation, wrote:
Insanity, then, is inordinate or irregular, or impaired action of the
mind, of the instincts, sentiments, intellectual, or perceptive powers,
depending upon and produced by an organic change in the brain.
In that same year, Dr. Amariah Brigham, one of the founders of American
psychiatry, also wrote that insanity "is now considered a physical disorder, a
disease of the brain."
It would be 150 years, however, before these statements could be proven.
Since the early 1980s, with the availability of brain imaging techniques and
other developments in neuroscience, the evidence has become overwhelming that
schizophrenia and manic-depressive disorder are diseases of the brain, just as
multiple sclerosis, Parkinson’s disease, and Alzheimer’s disease are diseases of
the brain. The brains of individuals with these diseases are measurably
different from individuals who do not have these diseases, both structurally and
functionally. A brief summary of some of the evidence that proves this point
follows.
Individuals with schizophrenia and manic-depressive disorder, including
those who have never been treated, have enlarged ventricles in the brain, as
demonstrated in over 100 studies to date.
Van Horn JD, McManus IC. Ventricular enlargement in schizophrenia. A
meta-analysis of studies of the ventricle:brain ratio (VBR). British
Journal of Psychiatry 160:687-697, 1992.
Soares JC, Mann JJ. The anatomy of mood disorders: review of
structural neuroimaging studies. Biological Psychiatry 41:86-106,
1997.
Elkis H, Friedman L, Wise A, et al. Meta-analyses of studies of
ventricular enlargement and cortical sulcal prominence in mood
disorders. Comparisons with controls or patients with schizophrenia.
Archives of General Psychiatry 52:735-746, 1995.
Individuals with schizophrenia, including those who have never been
treated, have a reduced volume of gray matter in the brain, especially in
the temporal and frontal lobes.
Lawrie SM, Abukmeil SS: Brain abnormality in schizophrenia: a
systematic and quantitative review of volumetric magnetic resonance
imaging studies. British Journal of Psychiatry 172:110-120, 1998.
Individuals with manic-depressive disorder have an enlarged amygdala and
increased numbers of white matter hyperintensities.
Strakowski SM, DelBello MP, Sax KW, et al. Brain magnetic resonance
imaging of structural abnormalities in bipolar disorder. Archives of
General Psychiatry 56:254-260, 1999.
Dupont RM, Jernigan TL, Heindel W, et al. Magnetic resonance imaging
and mood disorders: localization of white matter and other subcortical
abnormalities. Archives of General Psychiatry 52:747-755, 1995.
Videbech P. MRI findings in patients with affective disorder: a
meta-analysis. Acta Psychiatrica Scandinavica 96:157-168, 1997.
Individuals with schizophrenia and manic-depressive disorder, including
those who have never been treated, have more neurological abnormalities, as
shown in over 25 studies.
Schroder J, et al. Neurological soft signs in schizophrenia.
Schizophrenia Research 6:25-30, 1992.
Torrey EF, et al. Schizophrenia and Manic-Depressive Disorder.
New York: Basic Books, 1994, pp. 127 ff. and pp. 176-177.
Individuals with schizophrenia and manic-depressive disorder, including
those who have never been treated, have more neuropsychological
abnormalities that impair their cognitive function, including such things as
information processing and verbal memory.
Goldberg TE, Gold JM. Neurocognitive functioning in patients with
schizophrenia: an overview. In: Psychopharmacology: The Fourth
Generation of Progress, Bloom FE and Kupfer DJ (eds). New York:
Raven Press, 1995, pp. 1245-1257.
Hoff AL, Shukla S, Aronson T, et al. Failure to differentiate bipolar
disorder from schizophrenia on measures of neuropsychological function.
Schizophrenia Research 3:253-260, 1990.
Morice R. Cognitive inflexibility and pre-frontal dysfunction in
schizophrenia and mania. British Journal of Psychiatry 157:50-54,
1990.
Individuals with schizophrenia, including those who have never been
treated, show decreased function of the prefrontal area, an area of the
brain that we use for planning and thinking about ourselves.
Berman KF, Weinberger DR. Functional localization in the brain in
schizophrenia. In: Review of Psychiatry, vol. 10, Tasman A and
Goldfinger S (eds). Washington DC: American Psychiatric Press, 1991, pp.
24-59.
Andreasen NC, et al. Hypofrontality in neuroleptic-naive patients and
in patients with chronic schizophrenia. Archives of General
Psychiatry 49:943-958, 1992.
Approximately 50 percent of individuals with schizophrenia and
manic-depressive disorder, including those who have never been treated, have
impaired awareness of their own illness. This has been shown in at least 50
different studies. Such individuals do not realize that they are sick, and
they will, therefore, usually not accept treatment voluntarily. Studies
suggest that this impaired awareness is probably related to the decreased
function of the prefrontal area. These individuals are thus similar to some
patients who have had a stroke and, because of brain damage, are unaware of
their disability and deny it. The lack of awareness of illness in
individuals with schizophrenia and manic-depressive disorder is the most
common reason that they do not take their medication.
Amador XF, David AS. Insight and Psychosis. New York: Oxford,
1998.
Ghaemi SN. Insight and psychiatric disorders: a review of the
literature, with a focus on its clinical relevance for bipolar disorder.
Psychiatric Annals 27:782-790, 1997.
Peralta V, Cuesta MJ. Lack of insight in mood disorders. Journal
of Affective Disorders 49:55-58, 1998.
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