The relationship between cognitive insight and depression in psychosis and schizophrenia: a review and meta-analysis

Lack of insight is a commonly observed problem in patients with psychosis and schizophrenia. Clinical insight in patients has been associated with low mood. Cognitive insight is a recently defined concept, relating to the ability to self-reflect and the degree to which patients are over-confident regarding their interpretations of illness-related experiences, and is related to clinical insight. We therefore sought to investigate whether there is a positive relationship between cognitive insight and mood. A literature search identified 17 relevant papers published between 2004 and 2014. Our analysis indicated that there was a small but significant positive correlation between the composite index (CI) of the Beck Cognitive Insight Scale (BCIS) and depression scores, but this was driven by a significant positive relationship between depression and the BCIS self-reflection (SR) sub-scale, where low mood was related to higher SR scores. There was no significant relationship between the self-certainty sub-scale and depression. Post-hoc analysis indicated that different depression scales did not significantly affect the relationship with SR. Our results support the idea that cognitive insight is significantly related to mood in schizophrenia, and the effect size is similar to that between clinical insight and mood. Potential applications of this knowledge into treatment and rehabilitation are discussed and a model of cognitive insight is proposed.