Defective cognitive inhibition in depression

Abstract

This study examined attentional inhibition in depressed and nondepressed individuals using a computerized negative priming task. Previous research has suggested that defective inhibition may explain the selective attention deficits associated with depression (Lemelin et al., 1996; Linville, 1994; MacQueen, Tipper, Young, Joffe, & Levitt, 2000). This hypothesis was tested; in addition to testing the extent to which defective inhibition is associated with the ruminative response styles shown to exist in depressed individuals (Nolen-Hoeksema, 1987; 1991). Two samples of participants (N = 46, N = 29) completed the negative priming task, the Beck Depression Inventory (BDI-II; Beck, Steer & Brown, 1996), a diagnostic interview (Structured Clinical Interview for the DSM-IY Axis I Disorders; First, Spitzer, Gibbon, & Williams, 1996), the vocabulary section of the Shipley Institute of Living Scale (Zachary, 1986), and the Response Style Questionnaire (RSQ; Nolen-Hoeksema, 1987; 1991). These samples were analysed separately, compared for differences on the dependant variables, and then pooled as one sample. The resultant sample had 44 participants in the nondepressed group and 31 participants in the depressed group. The results failed to identify any differences between the depressed and nondepressed group on distractor inhibition for depression-related stimuli. Additionally, there were no negative priming effects in the overall sample. Supplementary analyses revealed that differences existed between the depressed and nondepressed group on the distractor portion of the negative priming task, indicating possible interference effects. Furthermore, a self-report measure o f rumination was found to be positively correlated with cognitive interference, while a self-report measure of distraction was negatively correlated with cognitive interference.