Could the severity of symptoms of schizophrenia affect ability of self-appraisal of cognitive deficits in patients with schizophrenia? Lack of insight as a mediator between the two domains.

Abstract

The relationship between subjective appraisal of cognitive deficits and symptom severity in schizophrenia is unclear. Insight reportedly affects both factors. Our aim is to further asses the relationship between subjective perception of cognitive deficits, symptom severity and lack of insight as a mediator variable. 109 subjects with schizophrenia were evaluated. Positive and Negative Syndrome Scale (PANSS) was modelled as independent variable, Subjective Scale to Investigate Cognition in Schizophrenia (SSTICS) as dependent and "Lack of Insight" (LoI) PANSS Item as mediator one. Mediation was assessed using bootstrap estimation approach. LoI acts as a suppressor variable (i.e., it enhances the relation between the independent and dependent variable) between Negative Symptoms and SSTICS, while showing a mediation effect between Depressive symptoms and SSTICS. LoI has a central role in mediating the relationship between negative and depressed symptoms on the one hand and self-appraisals of cognitive deficits (SACD) assessed with SSTICS on the other. Its suppressor role between negative symptoms and STICSS favour a direct effect of negative symptoms on SACD. On the other hand, its mediator role between depression and SSTICS is consistent with several reports of the 'insight paradox' of an enhanced severity of depression in patients with higher awareness of their disability.