The Mood Disorder Questionnaire (MDQ), developed by Hirschfeld and colleagues5 can serve as a screening tool and should be given to depressed patients to evaluate the likelihood of a prior manic or hypomanic episode. The MDQ consists of 13 yes/no questions derived from the DSM-IV criteria for bipolarity and clinical experience. If the patient checks off seven or more “yes” answers, several of these “yes” symptoms co-occurred, and this resulted in at least moderate psychosocial impairment, then there is a good likelihood of a past manic or hypomanic episode. The MDQ was validated in a study of 198 patients being treated in outpatient psychiatry clinics and demonstrated that patients with a screening score of 7 or more “yes” answers achieved a sensitivity of 0.73 and a specificity of 0.90 for identifying patients with bipolar spectrum disorder.5 Thus, although the MDQ is not diagnostic for bipolarity, it can help guide the evaluating clinician as to how to direct the clinical interview.
A recent study demonstrated the importance of obtaining a good family history. The study6 was designed to identify characteristics that would predict conversion from unipolar depression to bipolar depression and followed 91,587 Danish patients diagnosed with unipolar depression from 1995 through 2016. During the follow-up period, which included 702,710 person-years, a parental history of bipolar disorder was the strongest predictor of conversion.
If the past psychiatric history reveals prior episodes of mania, mania with mixed features or significant hypomania, the current major depressive episode should be treated as a BDI depression and antidepressant medications should be avoided. If the patient has never had a prior manic/hypomanic episode, differentiating BDI from unipolar depression is more challenging.
Over the past two decades, researchers have attempted to identify additional risk factors that may tip the evaluation scale more toward a likely diagnosis of either a unipolar depression or a BDI. The Table lists risk factors that should be assessed that would support a diagnosis of BDI depression as opposed to unipolar depression. However, it is important to note that none of these risk factors are diagnostic for bipolarity.
Ultimately, the decision to treat a patient who presents with a DSM-5 major depressive episode as an episode of unipolar depression versus BDI depression is made after factoring all of the information available at the time of treatment initiation. It is helpful to think of a balanced scale, with one side containing information suggesting the diagnosis of unipolar depression and the other side BDI depression. After adding all of the elements of the evaluation to the appropriate end of the scale, the likely diagnosis often becomes clear.
A patient who presents with a well-defined DSM-5 major depressive episode may have the primary diagnosis of either unipolar major depression or BDI depression. Since the choice of treatments are significantly different, obtaining a comprehensive initial history, utilizing scales like the MDQ, obtaining additional history from previous psychiatric treatment or from people that know the patient well can provide the clinician with an increasing degree of confidence in how to proceed. Unless hospitalization is indicated, or in the presence of other complicating factors, there is nothing wrong with delaying treatment for a day or a week while additional history is obtained. In the long run, it will pay off to begin a treatment that is more appropriate for the patient’s primary affective diagnosis.
Acknowledgement: Psychiatric Times extends a warm thank-you to Editorial Board members Dr. Ron Pies and Dr. John Miller for their support of this Special Report.
Dr Miller is Medical Director of Brain Health and Staff Psychiatrist at Seacoast Mental Health Center in Exeter, NH. Dr Miller notes he serves as a speaker/consultant for Sunovion and Otsuka/Lundbeck, and on the speaker’s bureau for Allergan and Teva. He is also on an advisory board for Alkermes and Janssen Virtual Feedback Committee, and has consulted for Align2Action.
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2. Geller B, Zimmerman B, Williams M, et al. Bipolar Disorder at Prospective Follow-Up of Adults Who Had Prepubertal Major Depressive Disorder. Am J Psychiatry. 2001;158:125-127.
3. Sachs G, Nierenberg A, Calabrese J, et al. Effectiveness of Adjunctive Antidepressant Treatment for Bipolar Depression. N Engl J Med. 2007;356:1711-1722
4. Ghaemi SN. Antidepressants in Bipolar Depression: An Update. Presented at the 29th Annual U.S. Psychiatric & Mental Health Congress; October 23, 2016; San Antonio, TX.
5. Hirschfeld R, Williams J, Spitzer R, et al. Development and Validation of Screening Instrument for Bipolar Spectrum Disorder: The Mood Disorder Questionnaire. Am J Psychiatry. 2000;157:1873-1875.
6. Musliner KL, Østergaard SD. Patterns and predictors of conversion to bipolar disorder in 91,587 individuals diagnosed with unipolar depression. Acta Psychiatr Scand. 2018; 137:422-432.