The British Journal of Psychiatry
The strength of the genetic effect. Is there room for an environmental influence in the aetiology of schizophrenia?
P McGuffin, P Asherson, M Owen, A Farmer


The evidence for a genetic contribution to schizophrenia is compelling. However, the pattern of inheritance is complex and it is usually assumed that environmental factors also have a role that will eventually be identified. We argue that this is not necessarily the case. While a hypothesis combining genetic diathesis with environmental stress cannot be disproved, it is also possible that 'non-genetic' factors consist entirely of stochastic events affecting gene expression or structure.