A diagnostic profile of those who return a false positive assignment on bipolar screening measures

ObjectivesOur aim was to identify the diagnostic profile of patients classified as ‘false positives’ on two bipolar screening measures; the Mood Swings Questionnaire (MSQ) and the Mood Disorders Questionnaire (MDQ).MethodsA total of 1534 patients attending the Black Dog Institute Depression Clinic completed the MSQ-46, and a smaller subset of 852 completed the MDQ. All patients underwent clinical assessment by one or more Institute psychiatrists.ResultsUsing clinical assignment (i.e. bipolar vs. unipolar) as the criterion measure for assessing the screening measures, the overall agreement rates were 84% for the MSQ-46 and 74% for the MDQ. Patients identified as ‘false positives’ were most likely to be clinically diagnosed as having a unipolar non-melancholic depression (37% for MSQ-46; 46% for MDQ), or a primary anxiety condition with secondary non-melancholic depression (19% for MSQ-46; 15% for MDQ). In addition, within the unipolar non-melancholic group, 46% of the MSQ-46 assigned false positives and 63% of the MDQ assigned false positives had co-morbid anxiety conditions.ConclusionsThese findings suggest that patients with anxiety conditions account for a significant proportion of false positive diagnoses on bipolar screening tests — a finding that should be conceded in the development and refinement of such screening measures and in clinical assessment of the possibility of a bipolar disorder.