Deficits in theory of mind and social anxiety as independent paths to paranoid features in schizophrenia.

Research suggests paranoia among persons with schizophrenia may be the result of a number of different psychological processes including deficits in theory of mind (ToM) and social anxiety. To test this hypothesis, this study sought to determine whether a group of highly paranoid persons with and without a ToM deficit could be detected and whether the group with paranoia and better ToM might have high levels of social anxiety. To explore this, a cluster analysis was performed on a group of 102 adults with schizophrenia spectrum disorders in a non-acute phase of illness on the basis of ratings of paranoid features using the Positive and Negative Syndrome Scale and levels of ToM deficit using a factor score which summarized four different ToM assessments. Four groups were produced: High Paranoia/Poor ToM (n = 14); Low Paranoia/Good ToM (n = 22); Low Paranoia/Low Middle ToM (n=29); and High Paranoia/High Middle ToM (n = 23). Groups were then compared on self report of social anxiety. As predicted, the group with levels of high paranoid features and relatively better ToM performance had significantly higher levels of social anxiety than all other groups.