The relationship between insight and neurological dysfunction in first-episode psychosis

Impaired insight is commonly seen in psychosis and some studies have proposed that is a biologically based deficit. Support for this view comes from the excess of neurological soft signs (NSS) observed in patients with psychoses and their neural correlates which demonstrate a degree of overlap with the regions of interest implicated in neuroimaging studies of insight. The aim was to examine the relationship between NSS and insight in a sample of 241 first-episode psychosis patients.

Total scores and subscale scores from three insight measures and two NSS scales were correlated in addition to factors representing overall insight and NSS which we created using principal component analysis.

There were only four significant associations when we controlled for symptoms. "Softer" condensed neurological evaluation (CNE) signs were associated with our overall insight factor (r = 0.19, P = 0.02), with total Birchwood (r = -0.24, P < 0.01), and the Birchwood subscales; recognition of mental illness (r = -0.24, P < 0.01) and need for treatment (r = -0.18, P = 0.02). Total neurological evaluation scale (NES) and recognition of the achieved effects of medication were also weakly correlated (r = 0.14, P = 0.04).

This study does not support a direct link between neurological dysfunction and insight in psychosis. Our understanding of insight as a concept remains in its infancy.