Lack of insight as a third variable between subjective appraisal of cognitive impairment and psychotic symptoms

Abstract

BackgroundThe relationship between subjective appraisal of cognitive deficits and symptom severity in schizophrenia is unclear. Insight reportedly impacts on both factors. Our aim is to further asses the relationship between the subjective perception of cognitive deficits, symptom severity and lack of Insight as a mediator variable.MethodsA total of 109 subject diagnosed with schizophrenia. Positive and Negative Syndrome Scale (PANSS) was modelled as dependent variable; Subjective Scale to Investigate Cognition in Schizophrenia (SSTICS) was modeled as independent variable and “Lack of Insight” (LoI) PANSS Item was tested as a mediator variable. Mediation was assessed using the Sobel Mediation Test.ResultsLoI acts as a suppressor variable (i.e. it enhances the relation between the independent and dependent variable) between SSTICS and negative symptoms, while showing a mediator effect between SSTICS and depressive symptoms.DiscussionLoI has a central role in mediating the relationship between subjective appraisal of cognitive deficits on the one hand and positive and depressed symptoms on the other. Its suppressor role between SSTICS and depression is consistent with several reports of an enhanced risk of depression in patients fully aware of their disability. Its mediator role between STICSS and positive symptoms supports the centrality of LoI as a metacognitive function whose failure may worsen psychotic symptoms.Disclosure of interestThe authors have not supplied their declaration of competing interest.