Frequency of normative word associations in the speech of individuals at familial high-risk for schizophrenia.

The intrusion of associations into speech in schizophrenia disrupts coherence and comprehensibility, a feature of formal thought disorder referred to as loosened associations. We have previously proposed that loosened associations may result from hyperactivity in semantic association networks, leading to an increased frequency of associated words appearing in speech. Using Computed Associations in Sequential Text (CAST) software to quantify the frequency of such associations in speech, we have reported more frequent normative associations in language samples from patients with schizophrenia and in individuals with schizotypal characteristics. The present study further examined this deviance in schizophrenia by studying normative associations in those who share genes with an individual with schizophrenia, (i.e. first-degree relatives of probands with schizophrenia; HR) but who do not have an illness. Familial high-risk participants (n=22), and controls (n=24) provided verbal responses to cards from the Thematic Apperception Test. CAST analysis revealed that HR used more associated words in their speech compared to controls. Furthermore, the frequency of normative word associations was positively correlated with dimensional and total scores of schizotypy derived from ratings of the structured interview for schizotypy, which confirms past research showing a relationship between schizotypy and hyperassociations. Our results suggest that some language disturbances in schizophrenia likely arise from an underlying psychopathological mechanism, hyperactivity of semantic associations.