[Construction of a depression scale with the Rasch model]

Area of Science:

• Psychometrics
• Clinical Psychology
• Adolescent Mental Health

Background:

• Traditional depression measures in Spanish youth may lack technical quality.
• There is a need for reliable and valid assessment tools for depression in this demographic.
• Psychometric evaluation is crucial for ensuring measurement accuracy.

Purpose of the Study:

• To examine the psychometric properties of a depression questionnaire for Spanish youth.
• To improve the technical quality of existing depression measures.
• To develop a reliable and valid scale for assessing clinical depression.

Main Methods:

• Utilized the Rasch model for data analysis.
• Administered a self-report questionnaire to 310 participants aged 18-24.
• Iteratively refined the scale by removing misfitting and sex-biased items.

Main Results:

• The Rasch model analysis indicated high average item reliability (.97) and person reliability (.88).
• After refinement, the scale demonstrated good model fit.
• The final scale objectively measures clinical depression and identified expected sex-related differences.

Conclusions:

• The revised depression questionnaire exhibits strong psychometric properties for Spanish youth.
• The scale provides a reliable and valid method for assessing clinical depression.
• The findings support the use of this enhanced measure in research and clinical practice.