Factors Predisposing to the Onset of Bipolar Disorder: A 30-Year Longitudinal Study.

OBJECTIVE

To examine the factors that predict the development of bipolar disorder in a population presenting with anxiety and depressive disorders.

METHOD: In a 30-year study, the Nottingham Study of Neurotic Disorder, the personality status, life events, service data, and early course of patients recruited to a randomised controlled trial were compared in patients who developed bipolar pathology and those who had no bipolar symptoms.

RESULTS

Over 30 years, 5 (2.5%) of 200 patients assessed at baseline developed unequivocal bipolar disorder, one within the first 10 weeks of the study, and three (1.5%) had bipolar II pathology. Analysis of these data showed that those patients who had some degree of bipolarity had an increase in anxiety and depressive symptoms and general psychopathology, most pronounced in the second year of the study, that was not found with patients who had no bipolar pathology.

CONCLUSIONS

Patients treated for anxiety and depressive disorders who remain unwell after initial treatment are more at risk of developing bipolar disorder than others.