The investigation of socioenvironmental influences began early in the history of schizophrenia research. As far back as the 19th century, reports emerged that insanity was more common among the lower social classes, and early in the 20th century this association was reported specifically for the diagnosis of schizophrenia. The association between low social class and schizophrenia was later confirmed by the classic study of Hollingshead and Redlich in New Haven in the 1950s (Hollingshead and Redlich, 1958). They suggested that the relation was causal: lower social class increased the risk of schizophrenia. This view was shortly disputed, however, in another classic study by Goldberg and Morrison (1963). Relying upon national registry data to establish occupation of father at birth, Goldberg and Morrison found that fathers of patients had a social class distribution similar to the population as a whole. Despite decades of work and further exceptional contributions (Link et al., 1986; Dohrenwend et al., 1992; also see Table 1.1), the matter is still not entirely resolved; however, the weight of evidence suggests that socioeconomic status has at most a modest effect on risk of schizophrenia. Therefore, while social class provided an early foothold in the examination of socioenvironmental influences in schizophrenia, no clear findings have emerged.

Nonetheless, emanating from this initial concern with social class, researchers have extended investigations to a broad range of socioenvironmental influences in schizophrenia.