|
Schizophrenia is probably the most debilitating
and unforgiving of all the mental disorders. It
keeps people from functioning at school, at work,
in relationships, and in society. Schizophrenia is
a disorder characterized primarily by psychotic
symptoms, including the following:
-
Hallucinations—false
visual, auditory, or tactile perceptions without
a realistic basis or external cause
-
Delusions—exaggerated
or distorted thoughts and perceptions of self
and others; or unrealistic belief in ability,
knowledge, or ideas
-
Disorganized thought—including
nonsensical associations and disorganized speech
-
Disorganized behavior—including
aggressiveness and wild gestures
-
Difficulty showing or expressing emotion—including
flattened behavior (rigid posture, inability to
move or talk, unresponsiveness)
Severe psychosis can last for more than 6 months.
Its course is different for men and women, and
schizophrenia can occur as early as age 15.
Because it tends to be a chronically pervasive
disease, an early onset implies lifelong
debilitating disease.
Schizophrenia affects about 1% of the population
worldwide, with some countries slightly lower and
others slightly higher. In the United States
alone, roughly 2,500,000 people suffer from it,
the majority of whom live in socioeconomically
disadvantaged rural areas.
The impact of schizophrenia on family, workforce,
and the economy is devastating. Schizophrenic
patients occupy 10% of hospital beds in the United
States. The disease costs the United States an
estimated 2% of its gross national product in
missed work, public assistance, and treatment
costs. Schizophrenia affects more people than
Alzheimer’s disease, diabetes, or multiple
sclerosis.
Schizophrenia does not mean "split personality,"
as popular media too often describe it. Rather, it
is a complex, biologically based mental disorder
caused by genetics, brain physiology, and other
risk factors. Its course is probably influenced by
a person’s environment, as well as biological
makeup. Although it can be incapacitating and is
typically incurable, it is treatable with
continual medication.
Back to Top
Causes
What causes schizophrenia is essentially unknown.
Several risk factors seem to prefigure it, the
most notable of which are genetics and brain
structure. And a combination of these is probably
most influential. In addition to these,
schizophrenia occurs with changes in brain
chemistry, specifically, excessive levels of
dopamine. Also, significant changes in the
activation of the brain’s frontal and parietal
lobes have been associated with schizophrenia.
The Dopamine Hypothesis
(for more information, see antipsychotic drug
treatment)
Dopamine is a neurotransmitter that transports
signals between nerve endings in the brain. It is
thought that the brains of people with
schizophrenia and other psychotic disorders
produce too much dopamine. There is evidence that
supports and counters the dopamine hypothesis.
The main support for the theory that too much
dopamine causes schizophrenia is the fact that
antipsychotic medications, which are used to treat
schizophrenia, block dopamine receptors. The
medications are designed to bind to dopamine
receptors in the brain, and their effects have
helped many people cope with symptoms. Secondly,
drugs that increase levels of dopamine, like
amphetamines, often cause psychotic symptoms and a
schizophrenic-like paranoid state.
However, several factors challenge the dopamine
hypothesis. For example, dopamine-related
psychosis occurs in many disorders, not
exclusively in schizophrenia. People with
schizophrenia are not the only ones who respond to
antipsychotic medication.
Antipsychotic medication may not significantly
affect the negative symptoms of schizophrenia,
which suggests that there is more involved than
abnormal dopamine levels alone. Moreover, dopamine
levels might actually be lower rather than higher
in the frontal lobes of the brain. At any rate,
antipsychotic medication only treats the symptoms
of schizophrenia; it does not eliminate its
underlying causes.
The theory that schizophrenia is partly a result
of abnormal brain function is useful in
understanding its biological basis. Underactive
frontal lobes and overactive parietal lobes are
thought to cause some of schizophrenia’s
associated symptoms. For example, when frontal
lobes are underactive, planning, organization, and
volition are all impaired. Frontal lobe
abnormalities are probably related to
schizophrenia’s negative symptoms.
Parietal lobes are involved in sensory perception,
like voice recognition, the ability to distinguish
patterns, and spatial orientation. Overactive
parietal lobes may cause distortion of these
senses, which is seen in many people with
schizophrenia. Parietal lobe abnormalities are
probably more closely related to positive
symptoms.
Risk Factors
Risk factors for schizophrenia include the
following:
-
Genetics
-
Abnormalities in brain structure
-
Abnormal brain chemistry (see Causes
-
Birth trauma
-
Seasonality (exposure to a virus)
-
Environmental conditions
Heredity
is the most well established risk. People who have
immediate family members with schizophrenia have a
10% chance of developing it, ten times that of the
general population. Other personality disorders,
including those with psychotic symptoms, also seem
to be more prevalent in families with
schizophrenia. Despite the chance for inheritance,
the number of children born to parents with
schizophrenia doubled in the first 50 years of the
20th century.
A recent study that seems to support a genetic
cause of schizophrenia suggests that identical
twins stand a 50% to 85% chance of sharing the
disease. Furthermore, it shows this to be about
three times that for fraternal twins. Still, most
studies fail to identify the exact mechanism and
location of genetic transmission, though they do
identify possible genes and chromosomes.
Because not all identical twins share the disease,
and because people without familial history
develop it, it is likely that there are other
physiological and environmental risk factors
involved.
Abnormal brain structure
is found consistently in people with
schizophrenia. This includes enlarged ventricles
and asymmetrical hemispheres. Computerized
functional imaging of the brain has found
decreased blood flow to the frontal lobes of
people with schizophrenia. These types of brain
abnormalities forecast certain symptoms, like loss
of attention, difficulty with abstract thinking,
and the inability to solve problems.
Some evidence suggests that infants who experience
birth trauma or complications while in the
womb are at greater risk for schizophrenia.
Maternal illness may play a part as well. A mother
who contracts a virus like the flu, especially
during her second trimester, may increase the risk
for her child. It is not known, whether the virus
itself or the immune response to it increases the
risk.
Some studies have shown that winter birth
may be assoicated with schizophrenia, especially
during immune response and illness. Furthermore,
viruses in the womb are more common during the
winter months. This has led some researchers to
consider intrauterine viral infection during the
winter as a risk factor. The same link, however,
is found for major mood disorders, like bipolar
disorder.
Environmental
factors and stress are thought to trigger the
onset of schizophrenia. For example, moving,
troubled relationships, problems at work, or
substance abuse may aggravate the constellation of
risk factors and lead to psychosis.
Symptoms
People with schizophrenia usually have a history
of acute psychosis. Psychosis is a disturbance of
mental health that is severe enough to cause a
change in normal personality, normal emotional
balance, as well as detachment from reality.
Psychoses occur with and without external cause.
In schizophrenia, they occur without external
cause, without gross changes in cerebral
structure.
Symptoms of schizophrenia include the following:
-
Hallucinations—false
visual, auditory, or tactile perceptions without
a realistic basis or external cause
-
Delusions—exaggerated
or distorted thoughts and perceptions of self
and others; or unrealistic belief in ability,
knowledge, or ideas
-
Disorganized thought—including
nonsensical associations and disorganized speech
-
Disorganized behavior—including
aggressiveness and wild gestures
-
Difficulty showing or expressing emotion—including
flattened behavior (rigid posture, inability to
move or talk, unresponsiveness)
Hallucinations
can pertain to any of the senses, but auditory
hallucinations are the most common in
schizophrenia. It is especially common for people
with schizophrenia to hear voices, which are
usually insidious and threatening. These voices,
which are sometimes familiar and other times
unknown, are always identified as separate from
the person’s own voice. These hallucinations can
include several voices that comment continually on
the person’s behavior. Hypnogogic and hypnopompic
hallucinations, those normally experienced while
falling asleep and waking up, are not associated
with schizophrenia.
Delusions
common in schizophrenia, like schizophrenic
hallucinations, are characteristically
antagonistic and threatening. For example,
delusions of persecution, which cause paranoia,
are most common. People may claim that they are
being harassed, followed, and provoked or that
they are victims of conspiracy.
Delusions that are unbelievable or fantastic are
referred to as bizarre. For example, people have
delusions of repeated alien contact, or that
someone has read their mind and either stolen or
replaced their thoughts—things for which there is
no established truth.
Disorganized thinking and speech
is considered by some to be the defining symptom
of schizophrenia. It often results in severely
impaired communication. Mild disorganization may
cause people with schizophrenia to switch subjects
during a conversation. Moderately impaired
thinking may result in speech that is vaguely or
loosely related. Severely disorganized thinking
often results in “word salad,” or incoherent and
incomprehensible speech.
Occasional confusion and disorganization is normal
for most people. In schizophrenia, however, the
degree of confusion and disorganization
significantly reduces or destroys a person’s
ability to communicate.
Disorganized and bizarre behavior
that is aggressive, childlike, exaggerated,
emotive, or socially unacceptable is another
definitive symptom of schizophrenia. Unprovoked
shouting, public exhibition, and constant
irritation are common examples. Appearance-based
behaviors constitute a significant portion of the
spectrum. For example, people with schizophrenia
have been known to routinely wear many layers of
clothing, regardless of the weather. They may be
disheveled or extremely dirty.
Disorganized behavior is not goal driven; that is,
the person does intend to behave a certain way.
This differs from delusional behavior, in which
delusions motivate a person's behavior.
Disorganized thinking and behavior are often
called the disorganized symptom cluster.
Generally, the symptoms in the cluster demonstrate
meaningless behavior and a loss of intention.
Because these symptoms are common to other mental
disorders and illnesses (in varying intensity),
extended observation is critical for a diagnosis
of schizophrenia.
Flattened affect
is the clinical term for the emotionless state
that is common in schizophrenia. People with
schizophrenia often do not express emotion and may
appear unaffected, distant, or unresponsive.
Although flattened affect is found in other mental
disorders, it is especially common in
schizophrenia.
People with catatonia often do not respond
to their environment. Their eye contact, facial
expression, attention span, and body language are
typically absent or significantly diminished. They
may become rigid and resist being touched or
moved. Catatonic stupor may precede an excited
phase during which the person suddenly exhibits
increased agitation or aggression.
Schizophrenia is sometimes classified according to
the predominance of certain symptoms (see
subtypes). For example, paranoid
schizophrenia typically features delusions and
hallucinations without disorganized speech, while
the disorganized type mainly features
inappropriate behavior instead of diminished
emotion.
The deterioration of function is probably
the most important symptom of the disorder. Major
areas of dysfunction include the following:
-
Interpersonal relationships
-
School (i.e., for children, especially)
-
Self-care
-
Work
People with schizophrenia typically have a hard
time keeping jobs. Some people have been known to
switch jobs or to get fired several times a month.
Many work at lower level jobs than their parents.
They often earn less money and make fewer
advances, instead of surpassing their parents’
socioeconomic level. The ability to form and
maintain relationships is usually hindered, in
both social and occupational settings. About
65% of people with schizophrenia never marry.
Personal hygiene and physical health often
decline, too.
Teenagers may experience difficulty in school, as
their attention span dissolves and their thinking
becomes impaired. As their peers are developing
new skills and new ways of thinking, children with
schizophrenia may lack the ability to think
abstractly and to solve problems.
Positive and Negative Symptoms
The symptoms of schizophrenia are classified as
either positive or negative.
Positive symptoms, like hallucinations and
delusions, are outward expressions that usually
involve distorted perceptions of reality. Negative
symptoms, like lack of emotion, loss of energy,
poor speech (alogia), and a loss of will to pursue
interests (avolition) refer to a reduction of
normal function. Generally, negative symptoms
distort internal emotional states. A schizophrenic
person typically has both positive and negative
symptoms.
Positive and negative symptoms
associated with schizophrenia include the
following:
-
Agitation (i.e., psychomotor agitation that can
cause rocking or pacing)
-
Confusion and disorientation
-
Hyperactivity and distractibility
-
Impaired coordination
-
Insomnia and sleep deprivation
-
Loss of appetite or delusional motivation to
resist eating
-
Loss of pleasure
-
Poor judgment and lack of insight
-
Sleeping too much
-
Slowed reaction, including poor eye movement and
tracking
-
Unexpected or inappropriate smiling, laugher, or
excitement
All symptoms are nonspecific; some are found in
neurological disorders, too. But nearly all people
who suffer from schizophrenia experience most of
them.
Treatment
Schizophrenia is seldom curable; it requires
chronic treatment to reduce suffering and to
restore daily function. Because schizophrenia is a
biological disease, it does not respond to changes
in environment or to support therapy alone.
Medication that influences brain activity is
the cornerstone of treatment, and behavioral
management therapy is used to support
medication in most cases. Research has shown a 90%
chance for recurrence in untreated schizophrenia
within a year of the first episode. The chance for
relapse drops to about 30% with treatment.
Hospitalization
is used primarily to achieve the following goals,
often at the onset of schizophrenia:
-
To evaluate and diagnose a person
-
To stabilize dangerous behavior
-
To begin medication
-
To monitor and ensure self-care and safety
-
To familiarize a person with treatment
Generally, hospitalization is brief and used
clinically to assess a person’s situation or
management skills, as the maintenance of normal
routine and function is the long-term goal of
treatment. Of course, a severe episode, especially
where the person’s safety is jeopardized, may
require extended hospitalization.
Medications
Medications used to treat schizophrenia include
the following:
-
Traditional antipsychotics (neuroleptic drugs)
-
Atypical antipsychotics
Antipsychotic
medications are the main drugs used to treat
schizophrenia. Their introduction in the 1950s
marked a breakthrough in the treatment of
psychosis, the results of which were apparent in
the reduction of hospitalized patients. It is
estimated that 300,000,000 people worldwide have
been treated with them, more than the current
population of the United States.
Antipsychotics reduce delusions, hallucinations,
and improve overall functioning. Generally, they
are divided into two subgroups, traditional and
atypical, which are used according to a person’s
response to treatment and tolerance of side
effects.
What Do They Do?
Traditional antipsychotics include
chlorpromazine (Thorazine®) and haloperidol (Haldol®).
These drugs primarily block the effects of the
dopamine 2 (D2) receptor, which are thought to be
hyperactive in the brains of people with
schizophrenia. This is supported by the fact that
dopamine suppression seems to improve
schizophrenic symptoms. Excessive numbers of
dopamine receptors have been found in the brains
of some people with untreated schizophrenia.
Dopamine is a neurotransmitter important to the
combined function of the limbic system and frontal
regions of the brain. Among other functions, it
assists in motor behavior, pleasure, and thought
and memory processes.
Thorazine® is considered a low-potency
drug. It frequently causes the following side
effects associated with suppression of the
neurotransmitter acetylcholine:
-
Constipation
-
Dizziness
-
Dry mouth
-
Sedation
-
Urinary retention
Acetylcholine is important in the brain in
counterbalancing dopamine levels. Neuromuscular
and neurological side effects are less common
with low-potency antipsychotics, but may occur in
some people. These include the following:
-
Acute dystonia (brief involuntary muscle spasm
and twisting)
-
Akathisia (severe restlessness that leads to
agitation and anxiety)
-
Mask-like expression
-
Pseudo-Parkinson’s disease (muscle tremor)
-
Shuffling, unstable gait
Haldol® and Prolixin® are high-potency
drugs used in treating schizophrenia. High-potency
drugs are more likely than low-potency drugs to
cause neuromuscular side effects. Their other
versions, Haldol Deconoate® and Prolixin Deconoate®,
are used to ensure dosage compliance in people who
may not consistently take oral medication. They
are given as a deep intramuscular injection—Haldol
Deconoate® once a month and Prolixin Deconoate®
every two weeks.
Other Side Effects and Limitations
In addition to other general side effects, there
are limitations to all antipsychotic medications.
For example, while they are useful in reducing the
positive symptoms of schizophrenia, like
delusions, hallucinations, and disorganized
speech, they are typically not as effective in
controlling negative symptoms, like lack of
emotion and loss of will.
Generally, people who take traditional
anitpsychotics always feel like they are on
medication. They can seem confused or lost, which
can adversely affect their judgment and physical
performance. For these reasons, they frequently do
not take their medication, so compliance is a
concern.
Tardive dyskinesia
(TD) is an involuntary movement disorder that
causes slow, nonrhythmic muscle movements, intense
aching, and painful spasms. It may appear late in
the treatment of schizophrenia as a result of
long-term use of antipsychotic medication, and can
affect specific muscles or general muscle groups,
from the tongue to the muscles of the arms and
legs. Every year, another 4% of people taking
traditional antipsychotic drugs develop TD. There
is no known effective treatment for TD, and it may
be irreversible.
Perhaps as many as 30% of people are not
affected by traditional antipsychotics and may
find benefit from treatment with atypical
antipsychotics.
Atypical
antipsychotics, like clozapine (Clozaril®), are
the most recent class of drugs used in
schizophrenia treatment. Clozapine’s method of
action only slightly affects the D2 receptor. It
primarily blocks other dopamine receptors and
other neurotransmitters, like norepinephrine,
histamine, and, especially, serotonin. Atypical
antipsychotics have helped more than 50% of people
who could not improve with traditional
antipsychotics.
There are two main advantages to clozapine.
First, it significantly improves negative symptoms
as well as positive symptoms; traditional
anitpsychotics typically only control positive
symptoms. Secondly, it is not associated with TD,
probably because TD results when the D2 receptor
is affected. For these reasons, clozapine is the
benchmark for schizophrenia treatment.
In addition to the side effects common with
traditional anitpsychotics, like sedation, dry
mouth, and dizziness, clozapine is associated with
agranulocytosis, an acute disease
characterized by significant loss of white blood
cells. It may be especially common in the first
two years of treatment. A little more than 1% of
people treated with clozapine develop it every
year. Therefore, weekly or biweekly blood-level
checks are necessary during treatment with
clozapine to ensure proper white blood cell
levels. This makes it an unpopular drug among
patients.
New Atypical Antipsychotics
The search for other drugs that work like
clozapine without the harmful side effects has
resulted in a new group, also considered atypical
antipsychotics. They typically cause fewer side
effects than traditional antipsychotics, including
a lower risk of TD and agranulocytosis. Like
clozapine, they help control negative symptoms,
and patients tend to comply with their use.
This new group of drugs includes the following:
-
Risperidone (Risperdal®)
-
Olanzapine (Zyprexa®)
-
Quetiapine (Seroquel®)
-
Ziprasadone (Zeldox®)
These drugs control psychosis by blocking dopamine
D2 receptors and the serotonin 5HT2 receptors in
the brain. The addition of a serotonin blocker may
be what boosts their efficacy.
The following are common side effects for
these medications:
Risperidone
-
Agitation
-
Anxiety
-
Headache
-
Insomnia
-
Muscle tremor
Olanzapine
-
Drowsiness
-
Headache
-
Insomnia
-
Nasal congestion
-
Weight gain
Quetiapine
-
Dizziness and vertigo
-
Drowsiness
-
Headache
Finally, ziprasadone is the most recent
drug to be approved by the Food and Drug
Administration (FDA). No statistical information
is yet available.
At this time, there are no established risks
associated with the use of antipsychotic drugs
during pregnancy. Clinical research
involving pregnant women is lacking. Women are
advised to discuss the benefits and risks with
their physician, especially during and after
pregnancy, since these drugs are excreted in
breast milk. |
