Examining Rates of Conversion From Unipolar Depression to Bipolar Disorder

Psychiatry Advisor: What are your thoughts on why the conversion rate from unipolar to bipolar disorder may decrease with time, according to these results?

Dr Gur: This is an interesting finding, but not surprising. We see the same phenomenon across neuropsychiatric disorders such as schizophrenia and Alzheimer disease. It means that by the time we make the initial diagnosis of risk, the train has already derailed. Unlike in the case of bipolar disorder, however, there are some predictors of conversion, although they are still limited. They include genomic, neurocognitive, and brain parameters — not examined in this study, which only included clinical predictors.

Psychiatry Advisor: What are the clinical implications of these results?

Dr Gur: The main implication is that we have to start earlier in the process of detecting signs and symptoms, and thereby be better poised to bend the curve in an ameliorating direction. By the time someone seeks help for a neuropsychiatric disorder, the course is well set. We need to reach out into the community we serve at an early age — most adult disorders have their origins in childhood.

Psychiatry Advisor: What should be next steps in terms of research in this area?

Dr Gur: [Future work should] incorporate neurocognitive and brain parameters with genomics and start in population-based lifespan samples that can be enriched for risk factors. Such designs are needed to establish valid conversion rates and identify individuals at risk who can benefit from intervention.

Psychiatry Advisor: Are there any additional points on the topic that you would like to note?

Dr Gur: This work is extremely important because the mental health specialist faces daily questions like “How will it turn out?” and “Will she always be like this, or will she get better or worse?” Making such predictions based on clinical presentation has major limitations. We have the tools to incorporate genomic, neurocognitive, and brain parameters, and it’s time that we do that. 

References

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5. Angst J, Sellaro R, Stassen HH, Gamma A. Diagnostic conversion from depression to bipolar disorders: results of a long-term prospective study of hospital admissions. J Affect Disord. 2005;84:149-157.
6. Kessing LV, Willer I, Andersen PK, Bukh JD. Rate and predictors of conversion from unipolar to bipolar disorder: a systematic review and meta-analysis. Bipolar Disord. 2017;19:324-335.