How do you score the Mood Disorder Questionnaire (MDQ)?

How to Score the Mood Disorder Questionnaire (MDQ)

The MDQ is scored by counting the number of "yes" responses to the 13 symptom items (Part 1), then determining if symptoms co-occurred during the same time period (Part 2), and finally assessing whether they caused moderate or severe functional impairment (Part 3); a positive screen requires ≥7 "yes" responses on Part 1, "yes" to Part 2, and endorsement of moderate-to-severe impairment on Part 3. 1, 2

Standard Scoring Algorithm

Part 1: Symptom Count

• Count the total number of "yes" responses to the 13 DSM-IV manic/hypomanic symptom items 1, 3
• Each item is scored as yes/no, covering all DSM-IV symptoms of mania/hypomania 3
• The standard threshold is ≥7 positive responses out of 13 items 1, 2, 4

Part 2: Temporal Co-occurrence

• Determine if the patient answered "yes" to the question asking whether several symptoms occurred during the same time period 2, 4
• This item assesses symptom clustering, which is essential for bipolar disorder diagnosis 2

Part 3: Functional Impairment

• Assess whether the patient endorsed moderate or severe problems caused by these symptoms 2, 4
• The standard algorithm requires moderate-to-severe impairment for a positive screen 2, 4

Performance Characteristics with Standard Scoring

• Using the standard algorithm (≥7 symptoms + co-occurrence + moderate-to-severe impairment), the MDQ demonstrates sensitivity of 63.5% and specificity of 84.8% in psychiatric outpatient settings 2
• The MDQ performs better for detecting bipolar I disorder (sensitivity 0.59) compared to bipolar II/NOS (sensitivity 0.19) 4
• Positive predictive value is approximately 33.7% and negative predictive value is 95.0% in psychiatric populations 2

Modified Scoring for Improved Sensitivity

When higher sensitivity is needed (such as in screening settings where missing cases is more problematic than false positives), eliminate the functional impairment requirement; this increases sensitivity from 63.5% to 75.0%, though specificity decreases from 84.8% to 78.5%. 2

Alternative Thresholds

• Lowering the symptom threshold to ≥3 items and eliminating both the co-occurrence and impairment requirements achieves optimal sensitivity and specificity balance in some populations 4
• A cut-off of 7 items without requiring impairment yields sensitivity of 68.1% and specificity of 63% 1

Clinical Interpretation Caveats

• The MDQ has inadequate sensitivity as a standalone screening measure when scored according to standard recommendations, particularly in heterogeneous psychiatric populations 2
• The instrument is more useful for ruling out bipolar disorder (high negative predictive value of 95%) than ruling it in (low positive predictive value of 33.7%) 2
• The MDQ demonstrates limited utility for detecting bipolar II disorder compared to bipolar I disorder 4
• A positive MDQ screen should prompt comprehensive diagnostic evaluation rather than serving as a definitive diagnosis 1, 2

Factor Structure of Symptoms

The 13 MDQ symptom items cluster into two independent factors: 3

• "Energized-Activity" factor (eigenvalue=3.1): includes increased energy, increased social activity, and related behavioral activation 3
• "Irritability-Racing Thoughts" factor (eigenvalue=1.5): includes irritable mood and racing thoughts 3

Notably, euphoria is neither sensitive nor pathognomonic for hypomania among bipolar II patients; energized activity and irritable mood with racing thoughts represent the modal hypomanic experiences 3