The relationship between biogenetic causal explanations and social distance toward people with mental disorders: results from a population survey in Germany.

Aims: Several studies have found an inverse relationship between people's readiness to endorse biogenetic causal explanations of mental disorder and their desire for social distance from people with mental disorders. The aim of this study is to examine why this may be the case.

Method: In the spring of 2001, a population survey was carried out among German citizens aged 18 years and older, living in private households. A total of 5025 interviews were conducted, reflecting a response rate of 65.1%. At the beginning of the personal, fully structured interview, respondents were presented with a vignette containing a diagnostically unlabelled psychiatric case history, either depicting a case of schizophrenia or major depressive disorder. Using five-point Likert scales, causal attributions as well as perceived dangerousness, fear and the desire for social distance were assessed.

Results: The more respondents endorse a brain disease as a cause, the more dangerous they believe the person with schizophrenia or major depression to be. Respondents who perceive the individual in the vignette as being dangerous express a higher degree of fear and a greater preference for social distance from these individuals. As compared with brain disease, the relationships between heredity and perceived dangerousness are less pronounced for both disorders.

Conclusions: Our analysis showed that endorsing biogenetic explanations decreases the likelihood of social acceptance of people with schizophrenia and major depression. Rejecting behavioural responses in the form of social distance desired from people with schizophrenia and major depression result from cognitive emotional processes in which biogenetic causal attributions are linked to lack of self-control, unpredictability and dangerousness, which, in turn, are associated with fear of these people.