Psychology and health instruments: scoring and validity
Fact sheets for psychology and health questionnaires: what they measure, how to score them, published reliability, cut-offs with their source, license and how to cite them.
One fact sheet per questionnaire with what you need before using it in your thesis, paper or practice: what it measures, how it is scored, the reliability reported by its validation studies, cut-off scores with their source, its license and how to cite it.
PHQ-9: Patient Health Questionnaire, depression module (9 items): Nine items, one for each DSM-IV criterion for a major depressive episode, used both to screen for depression and to grade the severity of symptoms over the last two weeks. Free to use, with a validated Spanish version.
GAD-7: Generalized Anxiety Disorder 7-item scale (7 items): Seven items to identify probable cases of generalized anxiety disorder and grade the severity of anxiety over the last two weeks. A sibling of the PHQ-9, free to use, with a validated Spanish adaptation.
DASS-21: Depression Anxiety Stress Scales, short form (21 items): Three 7-item scales measuring negative emotional states over the past week: depression, anxiety and stress (tension). Public domain, with Spanish translations hosted on the official website and a validation in Spanish university students.
Kessler Psychological Distress Scale (K10) (10 items): Ten questions on how often anxiety and depression symptoms occurred over the past 30 days, designed for population health surveys. Its six-item short form is the K6. Free to use with attribution, with official versions for Spain and for the Americas.
AUDIT: Alcohol Use Disorders Identification Test (10 items): Ten questions from the World Health Organization to detect hazardous and harmful drinking, and possible dependence, in primary care. Validated in six countries, free for non-commercial use, with a validated Spanish version.
CES-D: Center for Epidemiologic Studies Depression Scale (20 items): Twenty items on how often depressive symptoms occurred over the past week, designed for epidemiological studies in the general population rather than for diagnosis. Freely available, with a Spanish adaptation validated against clinical interview.
PANAS: Positive and Negative Affect Schedule (20 items): Twenty mood words that measure two relatively independent dimensions of affect, positive and negative, with a brief questionnaire that is easy to repeat. The time instruction decides whether you capture state or trait affect. With a Spanish validation.
Rosenberg Self-Esteem Scale (RSES) (10 items): Ten items for a single global score of self-esteem, in international use for more than five decades. Now in the public domain, with a Spanish validation in university students.
Commercially licensed instruments
GHQ-28: Goldberg’s General Health Questionnaire, scaled version (28 items): Screens for non-psychotic psychological distress in four areas —somatic symptoms, anxiety and insomnia, social dysfunction and severe depression— by comparing recent state with usual functioning. Commercially licensed, with a Spanish validation that set its own cut-offs.
What this is
Whenever you pick a questionnaire for a thesis or a paper you need answers to the same questions: what it really measures, how many subscales it has, what reliability its validation studies report, which cut-off to use and on what evidence, and how to get it legitimately. Those answers are scattered across papers and manuals; here they are gathered in one fact sheet per instrument, with every psychometric figure cited to its original publication in APA 7 format and every DOI checked against Crossref.
No fact sheet reproduces the wording of any item: each instrument is described in our own words and linked to its legitimate source (the authors’ website, the organization that publishes it or the open-access paper). When an instrument is commercially licensed, the fact sheet says so and links to the publisher.
There are three kinds of fact sheets. Scales validated by the author of this site, with their reference, DOI and a block to cite them in APA 7 and BibTeX. The free-to-use instruments most often used in health research, with their license checked at the official source. And commercially licensed instruments, with where to buy them.
This is an academic reference for information purposes: using an instrument in your research may require citing its authors or asking them for permission.