Interoceptive functioning in schizophrenia and schizotypy.

Though bodily self-disturbances are well documented in schizophrenia, interoceptive functioning (i.e., the perception of the internal state of the body) remains poorly understood in this population. In fact, only two studies to date have empirically measured interoceptive ability in schizophrenia. Both studies documented a deficit in interoceptive accuracy (i.e., the objective performance on a heartbeat detection task), and one noted differences in interoceptive sensibility (i.e., the subjective experience of interoception) in this population. To our knowledge, interoceptive awareness (i.e., the metacognitive awareness of one's interoceptive ability) has never been measured in schizophrenia and the link between interoceptive functioning and schizotypy remains unexplored. The present study addresses this gap by investigating the three dimensions of interoception in individuals with schizophrenia and matched controls (Experiment 1, N = 58) and in relation to schizotypal traits (Experiment 2, N = 109). Consistent with the literature, Experiment 1 documented a deficit in interoceptive accuracy and differences in interoceptive sensibility in individuals with schizophrenia. For the first time, our study revealed intact interoceptive awareness in individuals with schizophrenia. Against our expectations, we found no link between schizotypy and interoceptive functioning in Experiment 2. Our novel findings bear important clinical implications as insight into one's interoceptive limitations (i.e., intact interoceptive awareness) might promote treatment seeking behavior in schizophrenia. The lack of association between interoceptive ability and schizotypy in non-help-seeking youths suggests that changes in interoception may only arise with the onset of psychosis.