MDQ (Mood Disorder Questionnaire)

The Mood Disorder Questionnaire (MDQ) is a validated self-report screening instrument designed to identify individuals who may have bipolar spectrum disorders. Developed by Robert Hirschfeld and colleagues in 2000, the MDQ was created to address the significant diagnostic delay and misdiagnosis that characterizes bipolar disorder, where patients typically wait an average of 5-10 years from symptom onset to receiving a correct diagnosis.

Bipolar disorder affects approximately 2.8% of the U.S. adult population and 46 million people worldwide. It encompasses a spectrum of conditions including bipolar I disorder (characterized by manic episodes), bipolar II disorder (characterized by hypomanic and depressive episodes), and cyclothymic disorder. The depressive episodes that dominate the clinical presentation often lead to misdiagnosis as unipolar major depression, resulting in inappropriate treatment that can worsen outcomes.

The MDQ consists of three components: 13 yes/no questions derived from DSM-IV criteria for mania and hypomania, a question about whether symptoms occurred concurrently, and a question about the degree of functional impairment caused by the symptoms. The 13 symptom questions assess elevated mood, irritability, increased self-confidence, decreased need for sleep, pressured speech, racing thoughts, distractibility, increased energy, increased activity, increased sociability, hypersexuality, risk-taking behavior, and excessive spending.

The standard positive screen criteria require: (1) at least 7 of 13 symptom items endorsed, (2) symptoms occurring during the same time period, and (3) moderate or serious functional impairment. Using these criteria, the original validation study in a psychiatric outpatient setting reported sensitivity of 73% and specificity of 90% for bipolar spectrum disorders, with an overall diagnostic efficiency of 85%.

However, subsequent validation studies in community and primary care settings have shown lower sensitivity (28-58%) when using the standard criteria, though specificity remains high (85-97%). This variation highlights the MDQ's limitation as a screening tool that should prompt further clinical evaluation rather than serve as a diagnostic instrument. Some researchers have proposed modified cutoff criteria (e.g., 5 symptoms instead of 7) to improve sensitivity in non-psychiatric settings.

The MDQ has been translated into over 20 languages and is endorsed by multiple clinical guidelines for bipolar disorder screening. The American Psychiatric Association and the Canadian Network for Mood and Anxiety Treatments (CANMAT) recommend its use in primary care and psychiatric settings for screening individuals presenting with depression, mood instability, or treatment-resistant depression.

Clinical utility extends beyond initial screening. The MDQ can help identify bipolar disorder in patients currently diagnosed with unipolar depression who have failed to respond to antidepressant monotherapy, patients with recurrent depression, those with a family history of bipolar disorder, and individuals with substance use disorders (which co-occur in approximately 40-60% of bipolar patients).

This calculator implements the standard MDQ scoring algorithm with the three-component positive screen criteria, providing clinicians with a validated tool for bipolar disorder screening in clinical practice.