Denial of illness in schizophrenia as a disturbance of self-reflection, self-perception and insight

A substantial proportion of schizophrenia patients deny aspects of their illness to others, which may indicate a deeper disturbance of 'insight' and a self-reflection deficit. The present study used a 'levels-of-processing' mnemonic paradigm to examine whether such patients engage in particularly brief and shallow self-reflection during mental illness-related self-evaluation.

26 schizophrenia patients with either an overall acceptance or denial of their illness and 25 healthy controls made timed decisions about the self-descriptiveness, other-person-descriptiveness and phonological properties of mental illness traits, negative traits and positive traits, before completing surprise tests of retrieval for these traits.

The acceptance patients and denial patients were particularly slow in their mental illness-related self-evaluation, indicating that they both found this exercise particularly difficult. Both patient groups displayed intact recognition but particularly reduced recall for self-evaluated traits in general, possibly indicating poor organisational processing during self-reflection. Lower recall for self-evaluated mental illness traits significantly correlated with higher denial of illness and higher illness-severity. Whilst explicit and implicit measures of self-perception corresponded in the healthy controls (who displayed an intact positive>negative 'self-positivity bias') and acceptance patients (who displayed a reduced self-positivity bias), the denial patients' self-positivity bias was explicitly intact but implicitly reduced.

Schizophrenia patients, regardless of their illness-attitudes, have a particular deficit in recalling new self-related information that worsens with increasing denial of illness. This deficit may contribute towards rigid self-perception and disturbed self-awareness and insight in patients with denial of illness.