Sentiment in speech is associated with symptom severity in psychosis

Sentiment in the speech of people with schizophrenia spectrum disorder (SSD) may reflect psychosis severity. Previous research examines speech from semi-structured interviews or self-narrative prompts, where differences in measured sentiment may be driven by differences in life experiences. We measured sentiment in speech evoked from standardised stimuli among participants with a psychotic disorder.

Two cohorts (N = 97) participated in this study. Symptom domains were assessed using the Brief Psychiatric Rating Scale and were represented as Anxious Depression, Hostile Suspiciousness, Thought Disturbance, and Withdrawal Retardation. Participant speech during picture description tasks was quantified for sentiments: Valence, Arousal, Dominance, Happiness, Sadness, Anger, Fear, Disgust, and Surprise. Correlations between clinical and sentiment measures were conducted separately for the two cohorts and two timepoints in Cohort 1. Within-participant longitudinal relationships were examined with linear mixed models.

Several replicable relationships between sentiment and symptom severity were found: two replicable findings among Cohorts 1 and 2 and three replicable findings across Cohort 1 timepoints. Five findings were also generalised to within-participant longitudinal relationships.

Sentiment measures were related to the four symptom domains in the context of standardised stimuli, suggesting a disruption in emotion processing among people with a psychotic disorder.