Background: Theoretical models of mania suggest that people with bipolar disorder might be more susceptible to developing positive or activated mood states and associated cognitive biases. Naturalistic studies offer some support for these models, however replicable experimental induction techniques are also needed. The present study used an imagery-based mood and cognitive bias induction technique, called positive interpretation training (PIT; Holmes, Mathews, Dalgliesh & Mackintosh, 2006) to investigate these considerations. PIT had been used previously in those without a history of affective disorder but the present study was the first to apply it to a clinical population. Method: Individuals with a diagnosis of bipolar disorder (n=14) were compared with control participants with no history of depression, dysthymia, mania or hypomania (n=14). All participants were screened for current and past DSM-IV (1994) diagnoses using the SCID-I/P (First, Spitzer, Gibbon & Williams, 2002). Measures of current symptoms, trait anxiety and the tendency to use imagery in everyday life were administered on the day of testing. Measures of positive affect, behavioural engagement, state anxiety and positive and negative cognitive bias were given immediately before and after PIT. Results: Positive affect and behavioural engagement increased in both the bipolar and control groups following PIT, demonstrating that the induction technique was effective. However, there was no difference between groups in the degree to which these variables increased. There were differences between the groups on other measures. State anxiety decreased more following PIT in the bipolar group. On a measure of positive cognitive bias, there was a trend for both groups to show greater positive bias following PIT. Although no significant difference between the groups was found on this measure, effect sizes indicated that the increase in positive bias may have been particularly strong for the bipolar group. Negative cognitive bias decreased in those with bipolar disorder but not in the control group. Conclusions: The results provide preliminary indications that individuals with bipolar disorder show some differences relative to a control group in terms of their response to an imagery-based mood and bias induction technique. The greater reductions in anxiety and negative cognitive bias in those with bipolar disorder may have been a reflection of higher levels of anxiety and negative biases in this group initially, but are nevertheless of clinical relevance. The possibility that improvements in positive cognitive bias may have been stronger for the bipolar group, suggests that elevated positive responses in bipolar groups warrant further investigation. Overall, PIT offers a promising new method for investigating mood state dependent changes in activation and cognitive bias in bipolar disorder.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:505462 |
| Date | January 2009 |
| Creators | Wingfield, Emily |
| Publisher | University of Manchester |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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