A Longitudinal Study of Semantic Networks in Schizophrenia and other Psychotic Disorders Using the Word Association Task.

The underpinnings of language deviations in psychotic symptoms (eg, formal thought disorder, delusions) remain unclear. We examined whether the semantic networks underlying word associations are useful predictors of clinical outcomes in psychosis. Fifty-one patients with schizophrenia and other psychotic disorders and 51 matched healthy controls generated words in a Cantonese continued word association task. Patterns of word associations were examined using semantic similarity metrics derived from word embeddings (fastText) and the structure of individual semantic networks. A longitudinal design-baseline and 6 months later-enabled investigation of the relationship of changes in semantic associations in patients who were in an acute psychotic state at baseline compared to clinical stabilization 6 months later. The semantic similarity measure increased over time in patients, while it remained stable in controls. Moreover, the change in semantic similarity over time correlated with the changes in patients' formal thought disorder symptoms. There were differences in individual semantic networks between the groups at both time points. Patients had less structured networks on average, as evidenced by a smaller network diameter and clustering coefficient, and smaller average shortest path lengths. The identification of several state-like semantic measures that change over time with patients' mental states allows for nuanced comparison with clinical measures. Semantic measures are complex. Semantic similarity was a state-like measure that changed over time with mental state in psychotic disorders, whereas individual semantic network parameters were trait-like and stable over time.

The role of symptoms and insight in mediating cognition and functioning in first episode psychosis.

INTRODUCTION: Achieving functional recovery in patients with psychosis is a challenge in clinical practice. Investigating the complex interplay between cognition, symptoms, insight and functional outcome in first episode psychosis will be crucial to understanding the factors leading to better functioning. METHODS: In this 12-month prospective follow-up study, we investigated how cognition, clinical symptoms, and insight into illness affected overall functioning in 160 patients with first episode psychosis recruited from the Early Assessment Service for Young People with Psychosis (EASY) in Hong Kong from July 1, 2014 to June 30, 2016. Cognition was assessed at baseline while symptoms, insight, and functioning were assessed at 12-month follow-up. Structural equation modelling was used to examine the direct and indirect relationships between functioning and other latent constructs. RESULTS: Symptoms (negative symptoms and general psychopathology) and insight were shown to be significant mediators between cognition and functioning. The significant direct relationship between cognition and functioning (ß = 0.387; p < 0.001) became insignificant (ß = 0.079; p = 0.578) after including symptoms and insight in the model. Symptoms and insight were significantly associated with cognition (symptoms, ß = -0.469; p < 0.001; insight, ß = -0.372; p < 0.001) and predicted functioning (symptoms, ß = -0.558; p < 0.001; insight, ß = -0.264; p < 0.01). CONCLUSION: Symptoms and insight mediated the effects of cognition on functioning. Interventions for improving functioning in patients with first episode psychosis should target not only cognition but also symptoms and insight.