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 in Question 1, and a positive screen requires ≥7 "yes" responses, endorsement that several symptoms occurred during the same time period (Question 2), AND at least moderate functional impairment (Question 3). 1

Scoring Algorithm

Step 1: Count Question 1 Symptoms

• Sum all "yes" responses from the 13 symptom items in Question 1 (range: 0-13) 1
• These items assess manic/hypomanic symptoms including increased energy, decreased sleep need, grandiosity, racing thoughts, distractibility, increased activity, risk-taking behaviors, and irritability 1

Step 2: Assess Temporal Clustering (Question 2)

• Determine whether the patient endorsed that several of these symptoms occurred during the same time period 1
• This question must be answered "yes" for a positive screen, as it distinguishes bipolar episodes from isolated symptoms 1

Step 3: Evaluate Functional Impairment (Question 3)

• Assess the level of impairment caused by these symptoms using the response options: no problem, minor problem, moderate problem, or serious problem 1
• The original validated scoring requires "moderate" or "serious" impairment for a positive screen 1

Interpretation Thresholds

Standard Scoring Method (Original Validation)

• Positive screen = ≥7 symptoms + temporal clustering + moderate-to-severe impairment 1
• This method yields sensitivity of 73% and specificity of 90% in psychiatric outpatient populations 1
• Positive predictive value is approximately 34% in psychiatric settings, meaning most positive screens require diagnostic confirmation 2

Alternative Scoring Considerations

• Lowering the threshold to ≥7 symptoms + temporal clustering + any impairment (including mild) increases sensitivity to 75% but decreases specificity to 78.5% 2
• Further reducing the symptom threshold to ≥5 symptoms may increase sensitivity with minimal loss of specificity in high-risk populations, though this deviates from standard scoring 3
• In routine clinical practice, use the standard scoring method (≥7 symptoms + clustering + moderate impairment) to maintain adequate specificity 1, 2

Clinical Application

When to Use the MDQ

• Screen patients presenting with depressive symptoms to identify potential bipolar spectrum disorders that may be misdiagnosed as unipolar depression 1, 4
• Use in psychiatric outpatient settings where bipolar disorder prevalence is elevated 1, 2

After Scoring

• Any positive MDQ screen requires formal diagnostic assessment by a psychiatrist using structured clinical interview (such as SCID-IV bipolar module) to confirm or rule out bipolar disorder 1, 2
• A negative screen does not definitively exclude bipolar disorder, particularly bipolar II, as sensitivity is only 63.5-75% depending on scoring method 2

Common Pitfalls to Avoid

• Do not diagnose bipolar disorder based solely on MDQ results—the positive predictive value is too low (30-34%) for diagnostic certainty without clinical interview 2
• Do not ignore temporal clustering (Question 2)—symptoms must co-occur during the same period to suggest a manic/hypomanic episode rather than isolated traits 1
• Do not use the MDQ as a severity measure or treatment monitoring tool—it is designed only for initial screening 1
• Be aware that the MDQ performs poorly in distinguishing bipolar I from bipolar II disorder, requiring additional clinical assessment 4