10 - Social factors in schizophrenia

Social factors in schizophrenia

© SPMM Course Social factors in schizophrenia The significant social disadvantage (e.g. experience of racism, discrimination, economic and employment disadvantage, the perception of ‘outsider status’) is evident in populations with a higher risk of schizophrenia. According to the social defeat hypothesis, “long-term experiences of social disadvantage lead to sensitization of the... dopamine system and (or) to increased baseline activity of this system, thereby, to an increased risk for schizophrenia." Immigrant populations exemplify this link between social factors and schizophrenia. Stress and Social Adversity: Social adversity is associated with high degree of stress that can be exceptionally harmful in the context of vulnerability to psychosis. This has been demonstrated in many animal studies. Childhood Abuse and Family Dysfunction: While child abuse is not seen as a specific risk factor for schizophrenia, it is now accepted that childhood abuse may be a marker for other potential relevant risk factors, such as family dysfunction that increases the risk. Neighbourhood effect: In neighborhoods with ethnic minorities (non-white) that were at an increased risk, the risk reduced when the population of minorities increased. Similarly, natives had an increased risk in neighborhoods where minorities were larger in number, supporting the notion of social adversity in increasing the risk of schizophrenia. Urban Effect  There is a large deal of evidence now to support that in most parts of the globe, children born in urban environments are at an increased risk for psychosis (OR:1.61; CI: 1.4 – 1.8).  This urban-birth effect is not consistent among all countries; some Australian research has no increase in psychosis among urban areas.  Marcelis et al. (1998) (Dutch National Psychiatric Register study) found that the effect of urbanicity on all psychosis was greater for men than for women.  The effect of urban birth was greatest for individuals from the most recent birth cohorts and with an early-onset disease even after correcting for the length of followup.  Another study noted a positive correlation between admission rates for schizophrenia and degree of urbanization. There is a consistent dose–response relationship between urbanicity and risk of schizophrenia; the larger the town of birth, the greater the risk.

© SPMM Course Immigration and schizophrenia Though the frequency of most mental illnesses are found to be higher in migrants that the natives, schizophrenia has been studied the most. Conflicting explanations have been offered to explain why migrants have more schizophrenia. Cooper has revisited and reappraised the data available and summarised the main findings as below: a. The excess risk is not specific for African—Caribbean immigrants. It is also present among African-born Black immigrants to the UK, and to a lesser extent among immigrants from Asian countries. Hence, any explanation cannot be purely biological and not simply race specific. b. Incidence rates of schizophrenia in Caribbean countries are similar to those found in the indigenous UK population; this excludes country of origin theory which proposes that the immigrants carry such higher incidence rates from where they come from. The rate for schizophrenia in second-generation African—Caribbean people born in the UK appears to be higher than in the first generation, which is strongly suggestive of an environmental rather than a genetic effect. c. According to this notion of prepsychotic segregation, individuals who are psychosis prone find it hard to survive in the countries of birth and so immigrate to other regions. There is no evidence for selective immigration from the Caribbean as part of a pre-psychotic segregation. Also notable is the fact that apart from 1st generation immigrants having higher rates of psychosis, the 2nd generation children of immigrants also have a very high rate of psychosis (in some cases, higher than their parents), negating the probability of psychosis-induced immigration. d. The immigrants’ pathways to psychiatric care are characterized by long delays in seeking professional help, a lower likelihood of psychiatric referral, and frequent involvement of the police and emergency services and high proportions of compulsory and intensive care and secure (locked) ward admissions. The long-term outcome tends to be correspondingly unfavourable for immigrants. Hospital admission rates are consistently noted to be higher among ethnic minority population as a whole but variations between groups. In UK, highest rates of hospital admissions were noted among Irish migrants followed by people born in Caribbean. The rate of mental illness among South Asian population is notably lower than UK-born white population. It is unclear if these are effects of migration or social disadvantage or organisational differences in pathways of care. Census of inpatients, 2005 showed that 9% of in-patients were black or mixed black-white ethnicity while black patients were 44% more likely to have been sectioned & 50% more likely to have been put in seclusion. Black