In this work, 187 consecutive bipolar I inpatients hospitalized at Hospital Clínic of Barcelona for depressive, manic or mixed acute mood episodes underwent a standardized assessment. The analysis of the this data revealed five significant factors corresponding to "psychosis", "euphoric mania", "mixity", "dysphoria" and "inhibited depression". Thus the factor-structure of an acute episode of any type is pentafactorial. Each factor represents a major clinical dimension of different symptom sets that may be present across different mood episodes of bipolar illness.
The purpose of the dimensional approach to bipolar disorder is not simply descriptive, but aims at improving its treatment and outcome. In fact, the new results should prompt reconsideration of proposals for DSM-5 diagnostic criteria for the mixed features specifier. DSM-5 is a new version of the reference test for psychiatric diagnosis. This is the first major update in 19 years to the standard reference guide for diagnosing mental illnesses. A recent Editorial published in The American Journal of Psychiatry, with Dr. Eduard Vieta among the authors, underlined that the new test meant progress for many patients for whom the benefits of diagnoses and treatment were previously unrealized. Nevertheless, like the IDIBAPS - Hospital Clínic researchers point in their new article, it needs constant revision to establish improved, clinically sound, real-world diagnostic criteria.
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(3) Richard Van Noorden. New year, new science. Nature looks ahead to the key findings and events that may emerge in 2013. Nature. January 2013; 493: 11