Paranoia, depression and lack of insight in schizophrenia: a suggestion for a mediation effect

Delusional symptoms are heterogeneous and differentially related to insight, depression and another psychological construct, such as deservedness. In this study we explore models of relationships among these constructs, by hypothesizing that lack of insight could predict depression or paranoia, representing these variables outcome or mediator variables alternatively.

We evaluated positive psychotic symptoms, depression, persecution, deservedness and insight in a clinical sample of 81 people with schizophrenia or other psychotic spectrum disorders. Using multiple regression analyses we found 2 significant models. In the first one the lack of insight is negatively associated with depression and negatively related to persecution that, as mediator, is positively associated with depression. In the second model, lack of insight is negatively associated with persecution and negatively related to depression that, as mediator, is positively associated with persecution.

Persecution and depression could be not only predicted by insight but this prediction could also be mediated by the same variables. In both clinical models found in this study, insight does have a relevant role because the awareness about symptom/illness is crucial to the symptoms change. However, having good insight into schizophrenia can also be paradoxically associated with negative subjective states related to depression (the so-called "insight paradox").