Patent Self-Assessment Questionnaire

Abstract

The Patent Self-Report Questionnaire is the general term encompassing the Depression in the Medically Ill (DMI) scales, specifically the 10-item (DMI-10) and 18-item (DMI-18) versions. These instruments were primarily developed by Parker and colleagues starting in 2001 to efficiently screen for depression in populations that are concurrently experiencing physical illness, often referred to as the medically ill. The DMI scales employ a unique cognitive-based approach, deliberately omitting somatic symptoms that frequently overlap with general physical diseases.

This design enhances the diagnostic specificity of the scales by isolating the core psychological and affective components of depression, making them highly valuable in clinical and general practice settings characterized by high levels of comorbidity. By focusing on symptoms like hopelessness, self-criticism, and guilt, the DMI instruments aim to provide a clearer differentiation between physical discomfort and genuine affective distress.

Keywords

DMI-10, DMI-18, Depression screening, Medically ill, Cognitive symptoms, Affective symptoms, Self-report questionnaire, Psychometrics, Parker scales.

Authors

Gordon Parker, Tracy Hilton, Dusan Hadzi-Pavlovic, Jane Bains, Gin S. Gladstone, P. Irvine.

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Purpose

The principal objective of the DMI scales is to provide a specialized and streamlined screening instrument for identifying depressive symptomatology among individuals who are managing concurrent physical health conditions. Traditional measures of depression often include items related to somatic symptoms—such as fatigue, changes in appetite, or sleep disturbance—which are common manifestations of both clinical depression and various general medical illnesses. This overlap can lead to inflated scores and false positives when screening the medically ill population.

To overcome this diagnostic confounding, the DMI instruments were constructed to circumvent this issue by prioritizing psychological and affective distress markers, including elements of self-perception, guilt, hopelessness, and demoralization. This targeted approach yields a purer measure of affective distress, which is essential for clinicians in rapid assessment environments where accurate differentiation between physical symptoms and genuine depressive symptoms is necessary for effective treatment planning and intervention.

Construct

The DMI scales are founded on a theoretical construct that measures the core cognitive and affective domains central to major depressive disorder. The underlying premise is that these psychological symptoms are significantly less prone to score inflation resulting from poor physical health status than are traditional somatic markers. This explicit commitment to a cognitive-based approach aligns with modern psychological models that emphasize the foundational role of negative cognitions, hopelessness, and self-criticism in the etiology and maintenance of depression.

Specific dimensions assessed across the two versions include internalized distress (e.g., rumination or ‘stewing over things’), negative self-evaluation (e.g., feeling less worthwhile or self-critical), emotional state (e.g., feeling depressed or gloomy), and interpersonal withdrawal (e.g., feeling distant from others). The longer DMI-18 version extends the measurement breadth to incorporate additional anhedonic and emotional components, such as loss of interest and increased tearfulness, providing a slightly more comprehensive assessment of affective impairment.

Validity

The validity of the DMI scales has been empirically substantiated across multiple studies involving clinical populations. Research confirms the instruments possess strong discriminant validity, demonstrating their ability to successfully differentiate between patients diagnosed with clinical depression and those experiencing medical illness without a comorbid depressive episode. This is a critical feature given the scale’s specific target population of the medically ill.

Furthermore, the scales exhibit good concurrent validity when compared against established criterion standard diagnostic measures, notably the World Health Organization (WHO) Composite International Diagnostic Interview (CIDI) 2.1. Crucially, studies have shown that the DMI-10 maintains its efficacy not only among individuals with comorbidity but also in accurately detecting depression ‘caseness’ in psychiatric out-patients, suggesting robust clinical utility across varied medical and mental health settings (Parker & Gladstone, 2004).

Reliability

The DMI instruments exhibit acceptable psychometric reliability, supporting their continued use as dependable clinical screening tools. The primary measure of reliability reported is internal consistency, which confirms that the items within both the DMI-10 and DMI-18 consistently co-vary and measure the intended unified construct of affective and cognitive depression.

While precise reliability coefficients, such as Cronbach’s alpha values, are detailed in the original development papers, the consistent adoption of these scales in subsequent research confirms their stability and precision in measuring depressive symptoms across diverse adult populations. This high internal reliability is crucial, as it ensures that the instrument accurately captures the severity of depressive symptoms, making the resulting scores trustworthy for clinical decision-making regarding depression comorbidity.

Factor Analysis

The development of the DMI scales was rigorously guided by factor analytic investigation. This statistical approach was employed specifically to ensure that the selected items possessed high psychological relevance and minimized any potential overlap with common somatic symptoms associated with physical illness. The factor analysis successfully confirmed that the DMI items load strongly onto a single, primary factor reflecting core cognitive depression.

This resultant factor structure validates the instrument’s core theoretical distinction from traditional scales that include physical symptoms. By confirming a cohesive, unidimensional measure of affective distress, the factor analysis supports the DMI’s utility as a specialized screening tool, particularly vital in settings where physical symptoms are highly prevalent and could otherwise obscure genuine psychological distress.

Instrument

Test Type: Screening Instrument; Self-report questionnaire

Format: Paper-and-pencil inventory utilizing a 4-point Likert scale.

Language Available: English (Original research context is Australian).

Population Group: Clinical and general populations, specifically validated for the medically ill and psychiatric out-patients.

Age Group: Adults.

Population Details: The instrument is used in general practice studies and hospital settings specifically to screen for depression comorbidity. The items ask respondents to report on recent experiences or feelings.

Test Methodology: Respondents rate the extent to which each statement has been true for them based on a four-point scoring system: Not true = 0, Slightly true = 1, Moderately true = 2, Very true = 3. Total scores are calculated by summing the item scores, where higher scores correspond to greater severity of depressive symptoms. The original PDF can be downloaded here: http://www.blackdoginstitute.org.au/docs/DMI-10andDMI-18.pdf

Keywords

DMI, Depression screening, Affective symptoms, Cognitive depression, Parker scales, Psychometrics, Medical illness, General practice.

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Authors

Author ORCID Identifier: Not provided in source.

Affiliation Email addresses: Not provided in source.

Correspondence Address: Not provided in source (Affiliations are generally associated with the Black Dog Institute and the University of New South Wales).

Permissions & Fee and Test Year

The DMI scales were first introduced into peer-reviewed literature with publications in 2001 and 2002. Given their development context and public accessibility, often through the Black Dog Institute, the scales are typically used freely for non-commercial academic and clinical applications. However, organizations or researchers intending to utilize the DMI scales for commercial purposes or large-scale distribution are advised to seek explicit permission from the lead author, Gordon Parker, or the affiliated developing institution. The source material does not detail an explicit fee structure for standard non-commercial use.

Reference’s

• Parker G., Hilton T., Hadzi-Pavlovic D., Bains J. (2001). Screening for depression in the medically ill: the suggested utility of a cognitive-based approach. Australian & New Zealand Journal of Psychiatry, 35:474-480.
• Parker G., Hilton T., Bains J., Hadzi-Pavlovic D. (2001). Cognitive-based measures screening for depression in the medically ill: the DMI-10 and DMI-18. Acta Psychiatrica Scandinavica, 2002, 105(6):419-426.
• Parker G., Hilton T., Hadzi-Pavlovic D., Irvine, P. (2001) Clinical and personality correlates of a new measure of depression: a general practice study. Australian & New Zealand Journal of Psychiatry, 37(1): 104-9, 2003 Feb.
• World Health Organization (WHO) Composite International Diagnostic Interview 2.1 CIDI Interview manual (1997).
• Parker G., Gladstone G., (2004) Capacity of the DMI-10 depression in the medically ill screening measure to detect depression ‘caseness’ in psychiatric out-patients. Psychiatry Research, 127: 283-287.

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Items of the Patent Self-Report Questionnaire

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

DMI-10

1. Are you stewing over things?
2. Do you feel more vulnerable than usual?
3. Are you being self-critical and hard on yourself?
4. Are you feeling guilty about things in your life?
5. Do you find that nothing seems to be able to cheer you up?
6. Do you feel as if you have lost your core and essence?
7. Are you feeling depressed?
8. Do you feel less worthwhile?
9. Do you feel hopeless or helpless?
10. Do you feel more distant from other people?

DMI-18

1. Are you stewing over things?
2. Do you feel more vulnerable than usual?
3. Do you feel more ‘alone’ than usual?
4. Are you more tearful than usual?
5. Do you find you don’t enjoy doing the things you usually enjoy?
6. Do you feel gloomy about things?
7. Have you been feeling bad about yourself?
8. Do you feel more insecure than usual?
9. Are you being self-critical and hard on yourself?
10. Do you feel demoralized (i.e. disheartened)?
11. Are you feeling guilty about things in your life?
12. Do you feel as if you have lost your core and essence?
13. Are you feeling depressed?
14. Do you feel less worthwhile?
15. Do you feel hopeless or helpless?
16. Do you feel more distant from other people?
17. Have you lost interest in your usual activities?
18. Do you find that nothing seems to be able to cheer you up?

Scoring: Not true = 0, Slightly true = 1, Moderately true = 2, Very true = 3