3- Environmental Risk Factors

Question 1

7 environmental risk factors associated with schizophrenia

Answer 1

Season of birth
Viral epidemics
Population density
Prenatal malnutrition
Substance abuse
Interactions
Obstetric complications

Question 2

Research support associating season of birth to schizophrenia development

Answer 2

People born in late winter and early spring are more likely to develop schizophrenia

Question 3

Research support associating viral epidemics to schizophrenia development

Answer 3

Increased schizophrenia in people born after an influenza epidemic

Question 4

Research support associating population density with schizophrenia development

Answer 4

Schizophrenia likelihood 3 times higher in people living in middle of large cities than those living rurally

Question 5

Research support associating prenatal malnutrition to schizophrenia development

Answer 5

Low-birth-weight babies more likely to develop schizophrenia

Question 6

Research support associating substance abuse and schizophrenia development

Answer 6

Tobacco use in pregnancy –> increased schizophrenia risk

Question 7

Research support associating interactions with schizophrenia development

Answer 7

Mothers having pyelonephritis in pregnancy mean that a child is twice as likely to develop schizophrenia and 4 times more likely if there is a family history

Question 8

Research support associating obstetric complications with schizophrenia development

Answer 8

Higher schizophrenia risk when there is an emergency C-section, uterine complications, or foetal oxygen deprivation

Question 9

How does cannabis relate to schizophrenia?

Answer 9

Cannabis use associated with increased risk

Question 10

3 hypotheses about the association between tobacco and schizophrenia

Answer 10

1. Shared genetic influences
2. Smoking as a risk factor
3. ‘Self-medicating hypothesis’

Question 11

3 limitations of observed associations with environmental factors

Answer 11

1. Don’t control for underlying genetic factors
2. Difficult to control for confounds
3. Associations don’t prove causation

Question 12

What is the social defeat hypothesis?

Answer 12

Increased schizophrenia risk is caused by long-term exposure to social defeat causing sensitisation of mesolimbic dopamine pathway

Question 13

What model is integrated into the social defeat hypothesis?

Answer 13

Sociodevelopmental-cognitive model