Schizo Flashcards
What is psychosis defined by?
- Delusions: A fixed false belief, which is firmly held despite evidence to the contrary
and goes against the individual’s normal social and cultural belief system. - Hallucinations: A perception in the absence of an external stimulus. It is a common
feature of psychosis. - Thought disorder: An impairment in the ability to form thoughts from logically
connected ideas.
Epidemiology of psychosis
Psychotic disorders are relatively common, with schizophrenia being the most common.
The incidence of psychosis in England is roughly 31.7 per 100 000 people.
UK studies suggest a possible higher prevalence of psychosis in the black and ethnic
minority populations compared to the white population.
There are a variety of conditions that can present with psychosis (Fig. 4.1.1).
Non-organic causes of psychosis other than schizophrenia are covered in
Non-organic causes of psychosis
Schizophrenia
Schizotypal disorder
Schizoaffective disorder
Acute psychotic episode
Mood disorders with psychosis
Drug-induced psychosis
Delusional disorder
Puerperal psychosis
Organic causes of psychosis
Drug induced (Alcohol, acid, cannabis, mdma, cocaine, amphetamines)
Iatrogenic medications (Levodopa, methyldopa, steroids, antimalarials)
Delirium
Dementia
Huntington’s
SLE
Syphilis
Cushings
Vitamin b12 deficiency
Porphyria
What is the definition of schizotypal disorder?
Also known as latent schizophrenia, it is characterized by eccentric
behaviour, suspiciousness, unusual speech and deviations of thinking and
affect that is similar to those suffering from schizophrenia. These
individuals however, do not suffer from hallucinations or delusions. There
is an increased risk of schizotypal disorder in those who have first-degree
relatives with schizophrenia.
What is the definition of acute and transient psychotic disorders
A psychotic episode presenting very similarly to schizophrenia but lasting
<1 month and so not meeting the criteria for schizophrenia.
What is the definition of schizoaffective disorder?
Characterized by both symptoms of schizophrenia and a mood disorder
(depression or mania) in the same episode of illness. The mood symptoms
should meet the criteria for either a depressive illness or a manic episode
together with one or two typical symptoms of schizophrenia
What is the definition of persistent delusional disorder?
development of a single or set of delusions for a period of at least 3
months in which the delusion is the only, or the most prominent, symptom
with other areas of thinking and functioning well preserved, unlike in
schizophrenia. The content of the delusion is often persecutory, grandiose
or hypochondriacal in nature. The onset and content of the delusion is
often related to the patient’s life situation. Symptoms often respond well to
antipsychotics.
What is induced delusional disorder?
Induced delusional disorder, also known as ‘shared paranoid disorder’, is
an uncommon disorder characterized by the presence of similar delusions
in two or more individuals. Folie imposée is where a dominant person
(‘primary’) initially forms a delusional belief during a psychotic episode and
imposes it on another person(s) (‘secondary’). Folie simultanée is when
two people considered to suffer independently from psychosis, influence
the content of each other’s delusions so that they become identical or very
similar.
Definition of mood disorders with psychosis
Psychosis occurs secondary to depression or mania. On the other hand,
schizophrenia usually develops spontaneously
Puerperal psychosis (post-partum psychosis) definition
The acute onset of a manic or psychotic episode shortly after childbirth
(usually develops in the first 2 weeks following birth). It affects
approximately 0.2% of women.
Late paraphrenia definition
A term that is sometimes used to describe late-onset schizophrenia. It is
not coded for in ICD-10. Hallucinations and delusions (particularly
paranoid) are prominent, whereas thought disorders and catatonic
symptoms are rare.
ICD-10 Classification of schizophrenia and other psychotic disorders:
- Schizophrenia
- Schizotypal disorder
- Persistent delusional disorder
- Acute and transient psychotic disorders
- Induced delusional disorder
- Schizoaffective disorder
- Other non-organic psychotic disorders
- Unspecified non-organic psychosis
What is the definition of schizophrenia?
Schizophrenia is the most common psychotic condition, characterized by hallucinations,
delusions and thought disorders which lead to functional impairment. It occurs in the absence of
organic disease, alcohol or drug-related disorders and is not secondary to elevation or
depression of mood.
Aetiology of schizophrenia
The aetiology of schizophrenia involves both biological and environmental factors.
There is an increased likelihood of schizophrenia in those with a positive family history, and
monozygotic twin studies show a 48% concordance rate.
Factors that interfere with early neurodevelopment such as obstetric complications, fetal
injury and low birth weight lead to abnormalities expressed in the mature brain.
Adverse life events and psychological stress increase the likelihood of developing
schizophrenia.
Expressed emotion is the theory that those with relatives that are ‘over’ involved or that
make hostile or excessive critical comments are more likely to relapse.
Pathophysiology of schizophrenia
The dopamine hypothesis states that schizophrenia is secondary to over-activity of mesolimbic dopamine pathways in the brain. This is supported by conventional antipsychotics which work by blocking dopamine (D2) receptors, and by drugs that
potentiate the pathway (e.g. anti-parkinsonian drugs and amphetamines) causing psychotic
symptoms.
Epidemiology of Schizophrenia
Schizophrenia affects approximately 24 million people worldwide. The incidence of
schizophrenia is estimated to be 5 per 100 000 people.
Peak age of onset is 15–35 years.
Males and females are equally affected but a systematic review showed men aged <45
years had twice the rate of schizophrenia as women.
Predisposing factors to schizophrenia
Biological- Genetic: Monozygotic twinstudies – 48% concordance
Neurochemical: ↓
dopamine, ↓
glutamate, ↓
serotonin, ↓ GABA
Neurodevelopmental:
Intrauterine infection,
premature birth, fetal
brain injury and
obstetric
complications
Age 15–35
Extremes of parental
age: ≤20 years or
≥35 years
Psychological- Family
history: The
closer the
family relationship
to an affected
relative, the
higher the
risk
Childhood
abuse
Social: Substance misuse
Low socioeconomic
status
Migrants-Higher
incidence in migrant
populations (e.g.
African-Caribbean),
but not in offspring
born in the new
location
Living in an urban
area – although this
could be as a result
of urban drift into
cities.