Schizophrenia
is one of the most common severe mental illnesses and is reported to have a lifetime
incidence of 1%. Schizophrenia is typically diagnosed before age 25 and is
diagnosed equally in men and women.
When it is diagnosed after age 45, it is considered late onset. Schizophrenia is
characterised by
delusions
,
hallucinations
and lack of insight
.
Acute schizophrenia may also present with disturbed behaviour, disordered thinking,
or with insidious social withdrawal and other so-called negative symptoms and less
obvious delusions and hallucinations. Schizophrenia occurs worldwide in all ethnic
groups .Children of an affected parent have an approximate 10% risk of developing
the illness, but this rises to 50% if an identical twin is affected. The usual age of
onset is the mid-twenties but can be older, particularly in women.
Pathogenesis
1. genetic contribution.
2. Environmental risk factors
include a history of obstetric complications at the
time of the patient’s birth and urban upbringing.
3. Brain imaging techniques have identified subtle structural abnormalities in
groups of people with schizophrenia
, including an overall decrease in brain
size (by about 3% on average), with a relatively greater reduction in temporal
lobe volume (5–10%).
4. social stress and cannabis
, which increases dopamine turnover which lead to
increase Episodes of acute schizophrenia.
Consequently, schizophrenia is now viewed as a neurodevelopmental disorder,
caused by abnormalities of brain development associated with genetic predisposition
and early environmental influences, but precipitated by later triggers.
Clinical features
Acute schizophrenia should be suspected in any individual with bizarre behaviour
accompanied by delusions and hallucinations that are not due to organic brain
disease or substance misuse.
Hallucinations are typically auditory but can occur in any sensory modality. They
commonly involve voices from outside the head that talk to or about the person.
Sometimes the voices repeat the person’s thoughts.
Patients may also describe ‘passivity of thought’, experienced as disturbances in the
normal privacy of thinking, such as the delusional belief that their thoughts are being
‘withdrawn’ from them and perhaps ‘broadcast’ to others, and/or that alien thoughts
are being ‘inserted’ into their mind.
Other characteristic symptoms are delusions of control: believing that one’s
emotions, impulses or acts are controlled by others.
Another phenomenon is delusional perception, a delusion that arises suddenly
alongside a normal perception, such as ‘I saw the moon and I immediately knew he
was evil.’ Other, less common, symptoms may occur, including thought disorder, as
manifest by incomprehensible speech, and abnormalities of movement, such as those
in which the patient can become immobile or adopt awkward postures for prolonged
periods (catatonia).
2
symptoms of schizophrenia
8.23 Symptoms of schizophrenia
First rank symptoms of acute schizophrenia
•
A = Auditory hallucinations – second- or third-person.
•
B = Broadcasting, insertion/withdrawal of thoughts
•
C = Controlled feelings, impulses or acts (‘passivity’ experiences/ phenomena)
•
D = Delusional perception (a particular experience is bizarrely interpreted)
Symptoms of chronic schizophrenia (negative symptoms)
•
Flattened (blunted) affect
•
Apathy and loss of drive (avolition)
•
Social isolation/withdrawal (autism)
•
Poverty of speech (alogia)
•
Poor self-care
Diagnosis
The diagnosis is made primarily on clinical grounds but investigations may be
required to rule out organic brain disease.
The main differential diagnosis of schizophrenia includes:
•
Other functional psychoses,
particularly psychotic depression and mania, in which
delusions and hallucinations are congruent with a marked mood disturbance
(negative in depression and grandiose in mania). Schizophrenia must also be
differentiated from specific delusional disorders that are not associated with the
other typical features of schizophrenia.
•
Organic psychoses,
including delirium, in which there is impairment of
consciousness and loss of orientation (not found in schizophrenia), typically with
visual hallucinations; drug misuse, particularly in young people; and temporal lobe
epilepsy with psychotic symptoms, in which olfactory and gustatory hallucinations
may occur.
Many of those who experience acute schizophrenia go on to develop a chronic state
in which the acute, so-called positive symptoms resolve, or at least do not dominate
the clinical picture, leaving so-called negative symptoms that include blunt affect,
apathy, social isolation, poverty of speech and poor self-care.
Patients with chronic schizophrenia may also manifest positive symptoms,
particularly when under stress, and it can be difficult for those who do not know the
patient to judge whether or not these are signs of an acute relapse.
Schizophrenia is diagnosed by the presence of at least two of the following five
symptoms:
1
-delusions.
2
-hallucinations.
3
-disorganized speech.
4
-grossly disorganized or catatonic behavior.
5
- negative symptoms
.
At least one of the symptoms must be delusions, hallucinations, or grossly
disorganized behavior
DDX of schizophrenia
Alternative diagnosis Distinguishing features
Other functional psychoses
Delusional disorders
Absence of specific features of schizophrenia
Psychotic depression
Prominent depressive symptoms
Manic episode
Prominent manic symptoms
Schizoaffective disorder
Mood and schizophrenia symptom both prominent
Puerperal psychosis
Acute onset after childbirth
Organic disorders
Drug-induced psychosis
Evidence of drug or alcohol misuse
Side-effects of prescribed drugs
Levodopa, methyldopa, glucocorticoids, antimalarial drugs
Temporal lobe epilepsy
Other evidence of seizures
Delirium
Visual hallucinations, impaired consciousness
Dementia
Age, established cognitive impairment
Huntington’s disease
Family history, choreiform movements, Dementia
Investigations
As in dementia, investigations are focused on excluding a treatable cause, such as
slow-growing brain tumour .
temporal lobe epilepsy .
neurosyphilis.
various autoimmune conditions.
These are required only in patients with neurological or other organic symptoms or
signs.
28.24 Differential diagnosis of schizophrenia
Management
First-episode schizophrenia usually requires admission to hospital because patients
lack the insight that they are ill and are unwilling to accept treatment. In some cases,
they may be at risk of harming themselves or others. Subsequent acute relapses and
chronic schizophrenia are now usually managed in the community.
Drug treatment
Antipsychotic agents are effective against the positive symptoms of schizophrenia
in the majority of cases. They take 2–4 weeks to be maximally effective but have
some beneficial effects shortly after administration. Treatment is then ideally
continued to prevent relapse. In a patient with a first episode of schizophrenia this
will usually be for 1 or 2 years, but in patients with multiple episodes treatment may
be required for many years. The benefits of prolonged treatment must be weighed
against the adverse effects, which include extrapyramidal side-effects (EPSE) like
acute dystonic reactions (which may require treatment with parenteral
anticholinergics), akathisia and parkinsonism. For long-term use, antipsychotic
agents are often given by slow-release (depot)
injections to improve adherence.
A number of antipsychotic agents are available .
These may be divided into conventional (first-generation) drugs such as
chlorpromazine and haloperidol, and novel or second generation drugs such as
olanzapine and clozapine. All work by blocking D2 dopamine receptors in the brain.
Patients who have not responded to conventional drugs may respond to newer
agents, which are also less likely to produce unwanted EPSE but do tend to cause
greater weight gain and metabolic disturbances, such as dyslipidaemia. Clozapine
can be remarkably effective in those who do not respond to other antipsychotics but
can cause agranulocytosis in about 1% of patients in the first few months.
Prescription therefore requires regular monitoring of white blood cell count, initially
on a weekly basis, then fortnightly and monthly thereafter. Clozapine should not be
stopped suddenly because of the likelihood of relapse.
Two serious adverse effects deserve special mention.
Neuroleptic malignant syndrome
This is a rare but serious condition characterised by fever, tremor and rigidity,
autonomic instability
and delirium. Characteristic laboratory findings are an elevated
creatinine phosphokinase and leucocytosis.
Antipsychotic medication must be stopped immediately and supportive therapy
provided, often in an intensive care unit. Treatment includes ensuring hydration and
reducing hyperthermia.
Dantrolene sodium and bromocriptine may be helpful. Mortality is 20% untreated
and 5% with treatment.
Cardiac arrhythmias
Antipsychotic medications cause prolongation of the QTc interval, which may be
associated with ventricular tachycardia, torsades de pointes and sudden death. If this
occurs, treatment should be stopped, with careful electrocardiographic monitoring
and treatment of serious arrhythmias if
necessary .
Psychological treatment
Psychological treatment, including general support for the patient and family, is now
seen as an essential component of management. CBT may help patients to cope with
symptoms. There is evidence that personal and/or family education, when given as
part of an integrated treatment package, reduces the rate of relapse.
Social treatment
After an acute episode of schizophrenia has been controlled by drug therapy, social
rehabilitation may be required. Recurrent illness is likely to cause disruption to
patients’ relationships and their ability to manage their accommodation and
occupation; consequently, patients with schizophrenia often need help to obtain
housing and employment. A graded return to employment and sometimes a period
of supported accommodation are required.
Patients with chronic schizophrenia have particular difficulties and may need long-
term, supervised accommodation. This now tends to be in supported accommodation
in the community.
Prognosis
About one-third of those who develop an acute schizophrenic episode have a good
outcome. One-third develop chronic, incapacitating schizophrenia, and the
remainder largely recover after each episode but suffer relapses. Most affected
patients cannot work or live independently. Schizophrenia is associated with suicide
and up to 10% of patients take their own lives.