Cognitive vulnerability in patients with bipolar disorder
Background. No study has simultaneously explored key components of Beck's model of cognitive vulnerability to depression in people with bipolar disorders.
Methods. We compared 41 euthymic bipolar patients with 20 healthy control subjects. All subjects were assessed on the Hamilton Rating Scale for Depression, the Autobiographical Memory Test and the Mean Ends Problem-Solving procedure and also completed the Beck Depression Inventory, the Dysfunctional Attitude Scale, the Sociotropy Autonomy Scale and the Rosenberg Self-Esteem Questionnaire.
Results. In comparison to control subjects, patients with bipolar disorder demonstrated significantly higher levels of dysfunctional attitudes (particularly perfectionism and need for approval) and sociotropy, significantly greater over-general recall on an autobiographical memory test and significantly less ability to generate solutions to social problem-solving tasks. These between group differences remained significant when age, intelligence, latency to respond to autobiographical memory test cue words, and subjective mood ratings were included as co-variates in the statistical analysis. Within the patient group, cognitive dysfunction was significantly correlated with level of morbidity (as measured by number of previous illness episodes).
Conclusions. This study suggests that cognitive vulnerability in patients with bipolar disorder is similar to that described in unipolar disorders. It is not clear whether this dysfunction is a cause or an effect of repeated episodes of bipolar disorder. However, the findings may have implications for clinical treatment as well as suggesting a number of important new avenues of research into psychological models of affective disorder.
c1 Address for correspondence: Professor Jan Scott, University Department of Psychological Medicine, Gartnavel Royal Hospital, Glasgow G12 0XH