Investigating the 'jumping to conclusions' bias in people with anorexia nervosa.

Abstract

'Jumping to conclusions' (JTC) is an established reasoning bias in people with psychosis and delusion proneness. Research investigating the JTC bias in other clinical populations remains in its infancy. This study investigated whether individuals with anorexia (AN) displayed the JTC bias compared with healthy controls and, if so, whether the bias was greater in relation to emotionally salient information. The study also investigated whether delusionality was correlated with the JTC bias. JTC was measured using the 'beads task'. Three versions were employed: the standard version and two emotionally salient tasks. Results indicated that a majority (55.6%) of people with AN (n=26) displayed poor insight into their eating disorder beliefs but did not display an elevated JTC compared with healthy controls (n=33) on any task. The level of delusionality in the AN group was not correlated with JTC bias. Findings suggest that although a majority of people with AN demonstrated limited insight, they did not display the JTC bias. This may suggest that poor insight in eating disorders has different characteristics to that found in psychotic disorders, which may suggest that differences are needed in relation to how they are treated using psychological means. However, this was a small study, and study replication is required.