Schizophrenia

Question 1

What is the epidemiology of Schizophrenia?

Answer 1

Lifetime incidence 1%
Typically between the ages of 15-45
Men are typically affected younger and more severely.
However men and women are overall affected similarly.

Question 2

What is the aetiology of Schizophrenia?

Answer 2

There is a complex, multifactorial aetiology in Schizophrenia, affecting cause as well as course of disease.

Subtitles under aetiology in Psychiatry PRN.
Genetics
Obstetric complications
Substance misuse
Race and immigration status
Urban vs Rural living
Traumatic life events
Premorbid personality
Socioeconomic status
'expressed emotions'

Question 3

What aetiological factors for Schizophrenia might you find in the family history?

Answer 3

Other family members with schizophrenia
1st degree relative: 10% risk
Both parents with schizophrenia: 48% risk
Monozygotic twin: 40-50% concordance
Dizygotic twin: 10-20% concordance

Other family members with other mental health problems, particularly psychotic conditions such as schizoaffective disorder or affective psychosis?
Genes may be involved in clusters of symptoms
such as depression, mania and psychosis

Family history of substance misuse:
If schizophrenia linked to cannabis use then may have Val-Val genotype of COMT.

(Social aspect of family history:)
Immigration status
Relationship with family members - ‘expressed emotions’

Question 4

What aetiological factors for Schizophrenia might you find in the personal history:

Answer 4

Obstetric complications
Maternal pre-natal complications
Maternal viral infection
Pre-eclampsia
Low birth-weight
Emergency Caesarian section
Traumatic life events
Sexually abusive or traumatic events in childhood or adulthood.
Substance misuse
Cannabis and the val-val allele of COMT. (vs Met-Met)
Cocaine, amphetamines, LSD can cause psychotic symptoms

(Immigration status?)

Question 5

What aetiological factors for Schizophrenia might you find in the social history?

Answer 5

Urban vs rural living

Socioeconomic status

Question 6

What aetiological factors for Schizophrenia might you find in the premorbid personality history?

Answer 6

Schizoid personality in 25% of cases

Schizotypal personality linked to schizophrenia, there may be a genetic link for both.

Question 7

What obstetric complications can increase the risk of Schizophrenia? Why?

Answer 7

Maternal viral infection
Pre-eclampsia
Low birth-weight
Emergency Caesarian section
Also: catch-all term of Prenatal maternal complications.

May represent underlying genetic abnormalities or cause hypoxic brain injury.