The belief that being high is a natural part of your personality predicts an increase in manic symptoms over time in bipolar disorder.

Background: Several psychological models of bipolar disorder propose that certain types of appraisals can lead to increases in manic symptoms.

Aims: We tested whether the belief that being 'high' is a natural part of one's personality and correlates with manic symptoms 4 months later when controlling for manic symptoms at baseline.

Method: This was a prospective 4-month follow-up design using self-report measures. Forty people with a diagnosis of bipolar disorder completed a measure of manic symptoms, a measure of appraisals associated with bipolar disorder, and a single-item measure, 'To what extent do you feel like being "high" is a natural part of your personality?', at baseline and follow-up.

Results: The single-item measure showed modest stability over time and construct validity in its correlation with a standardised measure of appraisals in bipolar disorder. As predicted, the single-item measure correlated with manic symptoms at follow-up when controlling for manic symptoms at baseline.

Conclusions: The belief that being 'high' is a natural part of one's personality is a potential predictor of manic symptoms. Further research needs to study the potential mediating mechanisms such as activating behaviours, and control for indicators of the bipolar endophenotype.