Schizophrenia: The New Evidence
| Date | 01 September 2003 |
| Published date | 01 September 2003 |
| Pages | 31-34 |
| DOI | https://doi.org/10.1108/13619322200300027 |
| Author | Justin Kington,Robin Murray |
| Subject Matter | Health & social care |
The Mental Health Review Volume 8 Issue 3 September 2003 ©Pavilion Publishing (Brighton) 2003 31
Schizophrenia: The New Evidence
Justin Kington
Senior House Officer, Psychiatry
The Maudsley Hospital
Robin M Murray
Professor of Psychiatry
Institute of Psychiatry
The Front Edge
chizophrenia remains a disturbing and
sometimes devastating disorder but recently we have
made considerable progress in understanding the
underlying causes and how the clinical symptoms of
the illness arise.
New understanding of symptoms
An international study carried out by the World Health
Organisation (Jablensky et al, 1992) showed that the
syndrome we conventionally term schizophrenia exists
in all cultures. It most frequently commences in early
adult life and is slightly more common in men than
women; certainly it has an earlier onset and a worse
outcome in men. There is no definitive test for
schizophrenia; rather the diagnosis is still made by the
assessment of symptoms and signs over time, taking
into account the course of the illness and the exclusion
of other psychiatric or medical diseases. The use of
agreed international criteria for the diagnosis ensures
better diagnostic reliability but it does not help us to
know whether schizophrenia is one unitary disease or
is merely an umbrella term for several disorders (van
Os & McKenna, 2002). It is unlikely that that this will
be resolved until we understand fully the
psychological and physiological processes underlying
the symptoms
The core of schizophrenia is the experience of
hallucinations (false perceptions), particularly voices,
and the development of delusions (ideas that are
fixed, false and unshakeable). These ‘positive’
psychotic symptoms are accompanied in some but not
all people by ‘negative’ symptoms (for example,
blunted mood, little speech, lack of motivation); and
in others by ‘disorganisation’ (for example,
inappropriate mood, disturbance of the form of
thought, odd speech). Considerable advances have
Sbeen made in the last decade in understanding the
symptoms of schizophrenia.
Dopamine: the ‘wind of psychotic fire’
It is now well established that positive psychotic
symptoms result from an excess release in the brain of
a chemical transmitter called dopamine. Drugs which
increase brain dopamine, such as amphetamines, can
cause psychosis, while drugs that block dopamine
decrease psychotic symptoms; indeed, the latter is the
basis of all the drugs used to treat psychosis.
Dopamine is the neurotransmitter that determines
whether we pay attention to stimuli in our
environment, and how much importance we accord to
them. Consequently, when excess dopamine is
released in the brain the individual tends to assign
excessive importance to all sorts of irrelevant stimuli
and to develop the feeling that something immensely
significant is going on around him or her. Delusions
develop as a way of explaining these strange
perceptions (Kapur, 2003).
Voices as a misperception of inner speech
Remarkable progress has been made in understanding
what is going on in the brain when people experience
symptoms such as voices. New developments in brain
imaging show that when people are hearing voices,
Broca’s area is active, the area that is normally
involved in producing ‘internal speech’ (what you are
doing when you think in words or conjure up the
words of a poem in your mind). But during auditory
hallucinations, unlike normal ‘internal speech’, those
parts of the brain normally involved in processing
external speech are also activated. In others words, the
sufferer’s brain produces the internal words but then
fails to recognise them as internal and processes them
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