Schizophrenia
Schizophrenia is a psychiatric disorder denoting
a persistent, often chronic, major mental
illness primarily affecting thinking, with
attendant difficulties in perception of reality,
which in turn can affect behavior and emotion.
The term schizophrenia comes from the Greek
words σχίζω (schizo, split or divide) and φρενός
(phrenos, mind) and can be translated as
"shattered mind."
The primary sign of schizophrenia is considered
to be fragmentation of basic thought structure
and cognition. This disorganization is thought
to result in formal thought disorder, and the
inability to distinguish between internal and
external experience. People with schizophrenia
may report hallucinations or be observed
responding to them and may express clearly
delusional beliefs. Social or occupational
dysfunction, a number of secondary signs, and
the lack of organic brain disorder may be used
to confirm the diagnosis.
Mainstream research has suggested that both
biological and sociocultural influences are
important contributing factors, with current
research often focusing on the influences of
biochemical and genetic factors on the
neurobiology of the brain. The status of
schizophrenia is considered controversial by
some, who claim there is a lack of objectivity
in the stated diagnostic criteria.
In spite of its name, schizophrenia does not
involve a 'split personality', and should not be
confused with disassociative identity disorder
as it often is in literature, film and other
forms of popular culture. There is also no
association of schizophrenia with a
predisposition toward aggressive behavior. And,
not all people with schizophrenia are psychotic,
although it is such a state which usually brings
a schizophrenic to the mental health community.
Overview
Schizophrenia is most commonly characterized by
both 'positive symptoms' (those additional to
normal experience and behavior) and 'negative
symptoms' (the lack or decline in normal
experience or behavior). Positive symptoms are
grouped under the umbrella term psychosis and
typically include delusions, hallucinations, and
thought disorder. Negative symptoms may include
inappropriate emotional displays or flat
emotional affect, poverty of speech, and lack of
motivation. Some models of schizophrenia include
thought disorder and planning problems in a
third grouping, the 'disorganization syndrome'.
Additionally, neurocognitive deficits may be
present. These take the form of reduction or
impairment in basic psychological functions such
as memory, attention, problem solving, executive
function and social cognition. The onset is
typically in late adolescence and early
adulthood, with males tending to show symptoms
earlier than females.
Psychiatrist Emil Kraepelin was first to make
the distinction between what he called
dementia praecox and other forms of madness.
This classification was later renamed
'schizophrenia' by psychiatrist Eugen Bleuler in
1911 as it became clear Kraepelin's name was not
an adequate description of the condition.
The diagnostic approach to schizophrenia has
been opposed, most notably by the
anti-psychiatry movement, who argue that
classifying specific thoughts and behaviors as
illness allows social control of people that
society finds undesirable but who have committed
no crime
More recently, it has been argued that
schizophrenia is just one end of a spectrum of
experience and behavior, and everybody in
society may have some such experiences in their
life. This is known as the 'continuum model of
psychosis' or the 'dimensional approach' and is
most notably argued for by psychologist Richard
Bentall and psychiatrist Jim van Os.
Although no definite causes of schizophrenia
have been identified, most researchers and
clinicians currently believe that schizophrenia
is primarily a disorder of the brain. It is
thought that schizophrenia may result from a
mixture of genetic disposition (genetic studies
using various techniques have shown relatives of
people with schizophrenia are more likely to
show signs of schizophrenia themselves) and
environmental stress (research suggests that
stressful life events may precede a
schizophrenic episode).
It is also thought that processes in early
neurodevelopment are important, particularly
those that occur during pregnancy. In adult
life, particular importance has been placed upon
the function (or malfunction) of dopamine in the
mesolimbic pathway in the brain. This theory,
known as the dopamine hypothesis of
schizophrenia largely resulted from the
accidental finding that a drug group which
blocks dopamine function, known as the
phenothiazines, reduced psychotic symptoms.
These drugs have now been developed further and
antipsychotic medication is commonly used as a
first line treatment. However, this theory is
now thought to be overly simplistic as a
complete explanation.
Differences in brain structure have been found
between people with schizophrenia and those
without. However, these tend only to be reliable
on the group level and, due to the significant
variability between individuals, may not be
reliably present in any particular individual.
Diagnosis and presentation
(signs and symptoms)
Like
many mental illnesses, the diagnosis of
schizophrenia is based upon the behavior of the
person being assessed. There is a list of
diagnostic criteria which must be met for a
person to be so diagnosed. These depend on both
the presence and duration of certain signs and
symptoms.
The
most commonly used criteria for diagnosing
schizophrenia are from the American
Psychiatric Association's Diagnostic and
Statistical Manual of Mental Disorders (DSM) and
the World Health Organization’s International
Statistical Classification of Diseases and
Related Health Problems (ICD). The most
recent versions are ICD-10 and DSM-IV-TR.
To
be diagnosed as having schizophrenia, a person
must display:
A-
Characteristic symptoms: Two or more of the
following, each present for a significant
portion of time during a one-month period (or
less, if successfully treated)
-
delusions
-
hallucinations
-
disorganized speech (e.g., frequent derailment
or incoherence).
-
grossly disorganized or catatonic behavior
-
negative symptoms, i.e., affective flattening
(lack or decline in emotional response), alogia
(lack or decline in speech), or avolition (lack
or decline in motivation).
Note:
Only one Criterion A symptom is required if
delusions are bizarre or hallucinations
consist of hearing voices.
B
-
Social/occupational dysfunction: For a
significant portion of the time since the onset
of the disturbance, one or more major areas of
functioning such as work, interpersonal
relations, or self-care, are markedly below the
level achieved prior to the onset.
·
C- Duration: Continuous signs of the disturbance
persist for at least six months. This six-month
period must include at least one month of
symptoms (or less, if successfully treated) that
meet Criterion A.
