Communication disturbances in relatives beyond the age of risk for schizophrenia and their associations with symptoms in patients.

This article provides a detailed examination of subclinical disturbances in the natural speech of healthy relatives beyond the age of risk for schizophrenia. Speech samples from 43 stable schizophrenia outpatients, 42 nonschizophrenia parents of patients (pairs only), and 23 control subjects matched to the parents were analyzed for frequencies of six specific types of communication failures. The parents had higher overall communication disturbance ratings than the control subjects. The specific types of failures that occurred more frequently were unclarities caused by (1) language structural breakdown, (2) use of vague, overinclusive words, and (3) use of words with ambiguous meanings. In intrafamilial analyses, higher levels of communication disturbance in parents were associated with greater severity of illness in their patient offspring. These results support the idea that communication disturbances may be one manifestation of a stable genetic vulnerability to schizophrenia. The nature of the failures identified suggests the possible involvement of weaknesses in specific areas of cognitive functioning.