Psychological and Social Factors Flashcards
What did the WHO Ten-Country study suggest?
1980s - 1990s: rate in which new cases of psychotic disorder emerge in populations over time
- Narrow schizophrenia = classical symptoms : no significant differences across populations
- > schizophrenia uniform around the world
- Broad schizophrenia: wider variations in rates of schizophrenia
- > not uniform across populations
What did meta-analyses reveal after the WHO Ten-Country study (McGrath et al., 2004)?
- 100 studies reported incidence rates of schizophrenia (top and bottom 10% rates removed)
- Variation in incidence found across geographical areas: 7.7 to 43 per 100,000
= 5 fold variation in incidence - Incidence higher in males than females, urban areas, and migrant groups
Which findings are amongst the most replicated findings in the epidemiology of schizophrenia and psychotic disorders?
Incidence rate of schizophrenia is higher in:
- males than females
- urban areas
- migrant groups
How does the relative risk of schizophrenia vary according to where people lived in their childhood (Pedersen and Mortensen, 2001)?
- Most urbanised area: 2 times higher risk of schizophrenia than in rural areas
- Incidence reduced in individuals who moved out of urban environments
- Incidence increased when people moved in urban environments
- > increased interest in social factors in psychotic disorders
What is the dose response effect?
The higher the population density, the higher the risk
What do the meta-analysis on schizophrenia and migration show (Kirkbride et al., 2006)?
- Incidence is higher in all migrants (compared to non-migrant populations) (weighted relative risk: 2.9)
- Incidence is higher in developing countries (weighted relative risk: 3.3)
- Incidence is higher in majority of black population (weighted relative risk: 4.9)
What do meta-analyses show on psychosis and ethnicity show (Kirkbride et al., 2006; Morgan et al., 2006; Fearon et al., 2006)?
- Higher incidence of psychotic disorders amongst individuals who’ve migrated from countries with majority of black population (Caribbean, Sub-Saharan Africa)
- Migrant effect: incidence varies from different migrant groups (higher in groups are more visible minorities)
What do meta-analyses show on variations in the incidence of psychotic disorders between generations (Bourque, van der Ver and Malla, 2011)?
- No reduction in incidence rates
- Similar or even higher rates for 2nd generation
- Increased incidence is not primarily due to migration BUT rather living as minority in a majority population
What is the incidence of common psychotic experiences within the general population?
Up to 10%
What characterises the common psychotic experiences in the general population?
They share the qualities of psychotic experiences without the level of intensity, frequency or severity of psychotic disorders
- short-lived hallucinations
- low-level delusions and strange beliefs
- > share the same risk factors as psychotic disorder
What is the problem with studies that focused on psychotic experiences?
They rely on assumptions that psychotic experiences might give a clue to the risk of developing a psychotic experience
- psychotic experiences share same risk factors as psychotic disorder
What does the research on the social factors in psychosis relate to?
Psychotic experiences in the general population
What are the social risk factors of psychosis at the neighbourhood/area level?
- Ethnic density
- Population density
- Social fragmentation
- Deprivation
- Crime
What are the social risk factors of psychosis at the individual-level?
- Separation in childhood (e.g. abuse, bullying)
- Isolation in adulthood (e.g. life events, discrimination)
What did researchers in Chicago find out about the neighbourhood factors in the occurence of mental disorders (Faris and Dunham, 1939; Park and Burgess, 1925)?
- Occurence of schizophrenia much more common in the middle of city (downtown, fragmented areas)
- high levels of geographical / social mobility, crime, proportion of migrant groups, single person households or rented accommodation
- Incidence decreased when going out of those areas (heart of city)
What was the key issue with studies on neighbourhood/area factors of psychosis?
Is psychosis due to social drift or social causation?
- whether people have developed disorder prior to moving into these areas or is it living in these areas that increases the risk?