Self-reported and behavioural impulsivity in anorexia nervosa.

Aim: To examine how self-reported and behavioural impulsivity are related in anorexia nervosa (AN).

Methods: Twenty-four females with AN and 25 healthy controls (HC) participant in the study. Self-reported impulsivity was assessed with the Barratt Impulsiveness Scale (BIS-11). The scale yields three second-order factors: Attentional, motor and non-planning. Behavioural impulsivity was investigated with the continuous performance test (CPT), a computer-based task of sustained attention in which numbers are flashed briefly on screen and participants are required to click the mouse when the same number appears consecutively. The rate of commission and omission errors can be used a measure of behavioural imulsivity.

Results: AN participants self-reported increased attentional [AN: 20.67 (3.64), HC: 13.88 (2.91), P = 0.001] and reduced motor impulsivity [AN: 11.55 (2.28), HC: 14.08 (2.78), P = 0.002]. The rate of omission or commission errors on the CPT did not differ between groups (P > 0.05). BIS-11 and CPT measures did not significantly correlate, but attentional impulsivity was related to negative mood states in AN (depression: r = 0.52, P = 0.010, anxiety: r = 0.55, P = 0.006, stress: r = 0.57, P = 0.004).

Conclusion: The discrepancy between self-reported and behavioural impulsivity are discussed in terms of perfectionism in AN. Furthermore, it is suggested that improving negative mood states may resolve this inconsistency in AN.