Abstract
This program of research investigated the role and persistence of negative intrusive autobiographical memories in depression. Studies 1a, 2a and 3 compared the prevalence, content, features, appraisals and avoidance of intrusions in currently depressed, formerly depressed and never-depressed individuals. These studies found that specific memory characteristics (e.g., vividness), intrusion-related distress, negative appraisals and avoidance of intrusions distinguished depressed from never-depressed individuals. Moreover, the findings indicated that formerly depressed individuals also continued to endorse negative appraisals and avoidance of intrusions following a depressive episode. In Studies 1b and 2b, the degree of intrusiveness, negative appraisals, and distress associated with intrusions predicted depression symptoms at six month follow-up in untreated individuals. In contrast, the presence of intrusive memories alone was a poor predictor of depression. In a novel extension, Study 4 showed that assigning positive/benign appraisals to intrusive memories is associated with lower intrusion-related distress, providing the first evidence for the adaptive role of such appraisals. Together, these findings suggest that intrusive memories play an important role in the course of depression, and provide partial support for the applicability of cognitive models of PTSD (e.g., Ehlers and Steil, 1995) to account for the persistence of intrusions in depression. Study 5 compared the relative efficacy of a computerised cognitive bias modification (CBM) program that trained positive appraisals of intrusions and a single session of cognitive behavioural education (CB-Education) in their capacity to reduce negative appraisals, intrusion frequency and distress. Study 5 provided the first empirical evidence of the utility of both CB-Education and CBM appraisal bias training in reducing intrusion-related distress in dysphoria. Finally, Study 6 demonstrated an important and potentially maladaptive relationship between intrusive memories and ruminative responses to intrusive memories. In summary, these studies have extended our current understanding of the role of intrusive memories in the persistence of depression, and highlight the need for novel depression-specific theoretical models to account for the role and persistence of intrusions in the disorder. Finally, the findings from this program of research provide additional support for the utility of targeting negative intrusive memories in the treatment of depression.