Insight and psychotic illness. Cross-sectional and longitudinal associations

Insight has recently re-emerged as an important aspect of psychopathology amenable to empirical study. We sought to examine the relationship between various aspects of insight into illness and clinical, sociodemographic and neuropsychological variables. From an inner-London catchment area population, 150 in-patients with recent onset of psychosis were assessed on a variety of measures, including the Present State Examination (PSE). Subjects were followed up for a mean of four years and reassessed. High IQ was associated with better insight as rated on the PSE, while gender, ethnicity and a diagnosis of schizophrenia appeared to be unrelated. At follow-up, similar associations were found, as well as correlations with attitudes to treatment and a more elaborate measure of insight. Cerebral ventricular enlargement and tests of frontal lobe function did not correlate with insight, but there was a curious, strong association with left-handedness at both assessment points. Initial insight correlated significantly but weakly with insight at follow-up. The assessment of insight in psychosis has concurrent validity and is a distinct aspect of psychotic phenomenology. It may, in part, have a neuropsychological basis.