Description of the Questionnaire

The QD2 questionnaire is a self-report tool used to assess depressive symptoms in adults. It includes 13 questions that cover key aspects of depressive symptomatology, such as emotional state, psychomotor activity, sleep, self-esteem, and somatic symptoms. The participant is asked to respond based on how they have felt over the past 7 days.

Data Analysis and Usage

Each item is rated using a 4-point Likert scale: 0 for “Never or not at all,” 1 for “A little,” 2 for “Moderately,” and 3 for “Very much or constantly.” The total score ranges from 0 to 39, with higher scores indicating greater presence of depressive symptoms. Results are categorized as follows: 0–9 indicates no or minimal symptomatology, 10–19 mild symptoms, 20–29 moderate symptoms, and 30–39 severe depressive symptomatology. The data can be used for research purposes, population studies, or as a preliminary mental health screening tool, but it does not substitute for a clinical diagnosis by a mental health professional.

Purpose

The purpose of the QD2 is to provide a quick and reliable assessment of depressive symptoms through self-reporting, to serve as a screening tool for possible depression, and to monitor emotional state over time in longitudinal assessments.

Scoring and Calibration

The QD2 has been standardized in adult populations and has shown high internal reliability with Cronbach’s alpha values above 0.80. It has demonstrated positive correlations with other instruments such as the BDI and CES-D, confirming its convergent validity. The Greek adaptation follows the method of translation and back-translation from the original French version and has been applied in various Greek studies.

References

Pichot, P., & Boyer, P. (1986). “Questionnaire de Dépression QD2”, Editions Pierre Fabre. Pavlidou, E., & Chatziantoniou, M. (2009). Validation of the Greek version of the QD2 in a student population. Psychology, 16(1), 45–58. Radloff, L. S. (1977). The CES-D Scale: A self-report depression scale for research in the general population. Applied Psychological Measurement, 1(3), 385–401. Beck, A. T., Steer, R. A., & Brown, G. K. (1996). Manual for the Beck Depression Inventory-II. San Antonio, TX: Psychological Corporation.