Disruption of consciousness depends on insight in obsessive-compulsive disorder and on positive symptoms in schizophrenia.

Disruption of conscious access contributes to the advent of psychotic symptoms in schizophrenia and could also explain lack of insight in other psychiatric disorders. In this study, we explored how insight and psychotic symptoms related to disruption of consciousness in obsessive-compulsive disorder (OCD) and schizophrenia, respectively. Patients with schizophrenia, and patients with OCD with good versus poor insight and matched controls underwent clinical assessments and performed a visual masking task. We used a principal component analysis to reduce symptom dimensionality. We found that clinical dimensions could be isolated by principal components that correlated with consciousness measures. More specifically, positive symptoms were associated with impaired conscious access in patients with schizophrenia, whereas the level of insight delineated two subtypes of OCD patients, those with poor insight who had consciousness impairments similar to patients with schizophrenia, and those with good insight who resemble healthy controls. Our study provides new insights about consciousness disruption in psychiatric disorders, showing that it relates to positive symptoms in schizophrenia and with insight in OCD. In OCD, it revealed a distinct subgroup sharing neuropathological features with schizophrenia. Our findings refine the mapping between symptoms and cognition and confirm that consciousness disruption can be observed in various psychiatric disorders.