The Mood Disorder Questionnaire (MDQ) is a self-administered tool designed to screen for symptoms associated with Bipolar Disorder. Developed by Dr. Robert Hirschfeld and colleagues, its purpose is to help identify individuals who may have experienced manic or hypomanic episodes, which are often missed during routine medical evaluations. The MDQ is a screening instrument only, not a substitute for a comprehensive psychiatric evaluation or a formal diagnosis. A correct interpretation of the MDQ score indicates the likelihood that a person has symptoms consistent with a bipolar spectrum illness, prompting the need for further professional assessment.
Structure of the Mood Disorder Questionnaire
The MDQ is structured into three sections, each addressing a different aspect of symptom history and impact.
Part I: Symptom Checklist
The first section, Part I, is a checklist of 13 statements concerning behaviors and feelings related to mania or hypomania. These items cover experiences such as decreased need for sleep, racing thoughts, and increased energy, requiring a “Yes” or “No” response for each.
Part II: Timing
Part II consists of a single question that addresses the timing of any endorsed symptoms. This question asks whether several of the experienced symptoms occurred during the same time period. This temporal clustering is a defining element of mood episodes in clinical practice.
Part III: Impairment
The final section, Part III, focuses on the severity of the problem caused by the reported symptoms. The respondent is asked to rate the level of functional impairment, choosing from options like “no problem,” “minor problem,” “moderate problem,” or “serious problem.” All three parts must be considered together to determine a final screening result.
Calculating the Symptom Threshold (Part I)
The scoring process begins by evaluating the responses in the first section of the questionnaire, which contains the 13 items about manic and hypomanic symptoms. Each “Yes” response is counted as one point, and the total number of positive responses is tallied. This count establishes the preliminary symptom threshold.
For a positive screen to be generated, the established threshold requires at least seven “Yes” answers out of the 13 possible symptoms listed. Failing to meet this minimum count of seven positive responses means the overall screen is negative, regardless of the answers in the subsequent parts. This threshold of seven symptoms was selected by the questionnaire’s developers to balance the tool’s ability to correctly identify individuals with the condition (sensitivity) against its ability to correctly rule it out (specificity). Meeting this symptom count alone acts as the initial requirement for moving forward in the scoring algorithm.
Determining Clinical Significance (Parts II and III)
Once the minimum of seven positive symptoms is met in Part I, the responses from the remaining two sections are assessed to determine the clinical significance of those symptoms.
Part II Requirement
Part II asks if the endorsed symptoms occurred simultaneously, meaning they happened during the same distinct time period. For the screen to be positive, the answer to this question must be “Yes,” confirming that the symptoms clustered together rather than occurring as isolated events over a lifetime.
Part III Requirement
The final criterion involves the response to Part III, which measures the degree of functional impairment caused by the symptoms. To meet the threshold for a positive screen, the respondent must indicate that the symptoms caused at least a “Moderate problem” or a “Serious problem.” Responses indicating “no problem” or only a “minor problem” will result in a negative screen. All three criteria—seven or more symptoms, simultaneous occurrence, and moderate or serious impairment—must be met to trigger a positive result on the MDQ.
Interpreting a Positive Screen
A positive result on the Mood Disorder Questionnaire indicates a strong possibility that the individual has experienced symptoms consistent with a bipolar spectrum disorder. The original validation studies for the MDQ showed that meeting all three scoring criteria has a high degree of accuracy for identifying cases that warrant further investigation. Specifically, the tool has demonstrated effectiveness in identifying the majority of individuals who have bipolar disorder.
Despite its accuracy as a screening tool, a positive MDQ score is not a diagnosis and should not be treated as one. The result serves as a signal that a comprehensive evaluation by a licensed mental health professional, such as a psychiatrist or clinical psychologist, is necessary. The clinician will use the screening information, along with a detailed clinical interview and history, to determine if the full diagnostic criteria for Bipolar Disorder are met. Seeking professional assessment ensures that any potential condition is accurately diagnosed and that appropriate treatment recommendations can be provided.