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

How to Score the Mood Disorder Questionnaire (MDQ)

The MDQ is scored by counting "yes" responses to the 13 symptom items in Question 1, with a positive screen defined as ≥7 "yes" responses that occurred during the same time period (Question 2) AND caused at least moderate functional impairment (Question 3). 1

Scoring Algorithm

Step 1: Count Symptom Endorsements

• Sum all "yes" responses from Question 1 (13 items assessing manic/hypomanic symptoms) 1
• Each "yes" counts as 1 point, for a maximum possible score of 13 1

Step 2: Verify Temporal Clustering

• Check Question 2: "Have several of these ever happened during the same period of time?" 1
• This must be answered "yes" for a positive screen 1
• This requirement ensures symptoms represent a distinct mood episode rather than isolated occurrences 1

Step 3: Assess Functional Impact

• Review Question 3: "How much of a problem did any of these cause you?" 1
• The original scoring requires at least "moderate problems" or "serious problems" for a positive screen 1
• Responses of "no problem" or "minor problem" do not meet threshold 1

Step 4: Determine Final Result

• Positive screen: ≥7 symptoms + temporal clustering (yes) + moderate-to-severe impairment 1
• Negative screen: Fails to meet any of the three criteria above 1

Performance Characteristics

• Sensitivity: 73% (original scoring method) 1
• Specificity: 90% (original scoring method) 1
• The original scoring method maximizes specificity but has relatively lower sensitivity 2, 3

Alternative Scoring Considerations

Modified Thresholds for Higher Sensitivity

• Lowering the symptom threshold to ≥5 items increases sensitivity with minimal loss of specificity 2
• Removing the impairment requirement increases sensitivity to 75% but decreases specificity to 78.5% and reduces positive predictive value to below 30% 3
• In psychiatric outpatient settings, the standard scoring showed only 63.5% sensitivity, raising concerns about missed cases 3

Clinical Context Matters

• In populations at high risk for bipolar disorder, consider using ≥5 symptoms as the threshold 2
• In general psychiatric settings where false positives are costly, maintain the original ≥7 symptom threshold with impairment requirement 1, 3

Critical Implementation Points

• The MDQ is a screening tool, not a diagnostic instrument 1, 4
• All positive screens must be followed by comprehensive psychiatric evaluation using structured diagnostic interviews 1, 4
• The MDQ performs best in psychiatric populations and has not been validated for general medical settings 1
• Missing data on any component invalidates the screen 3

Common Pitfalls to Avoid

• Do not diagnose bipolar disorder based solely on MDQ results - always conduct full diagnostic assessment 1, 4
• Do not ignore the temporal clustering requirement - symptoms must have co-occurred during the same period 1
• Do not use modified scoring without understanding the trade-offs - lowering thresholds increases false positives 2, 3
• Do not apply in unvalidated populations - the MDQ was developed and tested primarily in psychiatric outpatient settings 1