Genetics, Risk Factors, and Personality Factors

It is no longer heresy to state that schizophrenia has a neurobiological basis (Henn 1995) and that the most convincing risk factor is genetic loading for the disorder (Eaton et al. 1995). A recent workshop on schizophrenia recommended that a major focus should be on the search for predisposing genes and that there should be parallel research in many other areas (Barondes et al. 1997). Theorizing about schizophrenia now seems to have abandoned fiction and to have rediscovered facts. The fact is that, of all the currently known risk factors for the disease, genes are the most important: winter birth, stressful life events, unmarried, and low economic status increase the relative risk for schizophrenia by 1.1, 2.7, 2, and 4 respectively, whereas inferred genetic factors lead to relative risks ranging from 10 to 50 (Hafner 1987; Eaton et al. 1995; Jablensky 1995).