Strengths & Difficulties Questionnaire.

The SDQ is a brief psychological assessment tool for 2-17 year olds. It exists in several versions to meet the needs of researchers, clinicians, and educators. Each version includes between one and three of the following components:

  1. 25 items on psychological attributes
  2. An impact supplement
  3. Follow-up questions

1) 25 items on psychological attributes. These 25 items are divided between 5 scales:

  • The same 25 items are included in questionnaires for completion by the parents or teachers of 4-16 year olds (Goodman, 1997).
  • A slightly modified informant-rated version for the parents or nursery teachers of 3 and 4 year olds. 22 items are identical, the item on reflectiveness is softened, and 2 items on antisocial behavior are replaced by items on oppositionality.
  • Questionnaires for self-completion by adolescents ask about the same 25 traits, though the wording is slightly different (Goodman et. al., 1998). This self-report version is suitable for young people aged around 11-16, depending on their level of understanding and literacy.

2) An impact supplement

These extended versions of the SDQ ask whether the respondent thinks the young person has a problem, and if so, enquire further about chronicity, distress, social impairment, and burden to others.  This provides useful additional information for clinicians and researchers with an interest in psychiatric caseness and the determinants of service use (Goodman, 1999).

3) Follow-up questions

The follow-up versions of the SDQ include not only the 25 basic items and the impact question, but also two additional follow-up questions for use after an intervention. Has the intervention reduced problems? Has the intervention helped in other ways, e.g. making the problems more bearable? To increase the chance of detecting change, the follow-up versions of the SDQ ask about ‘the last month’, as opposed to ‘the last six months or this school year’, which is the reference period for the standard versions. Follow-up versions also omit the question about the chronicity of problems.

Download Paper-based SDQ

Uses of the SDQ.

The Strengths and Difficulties Questionnaire (SDQ) is an online assessment tool for 2-25 year olds. The SDQ has been used by over 4,000 research studies and administered over 5 million times. It exists in several versions to meet the needs of researchers, clinicians and educators.


SDQplus is a web-based application to facilitate longitudinal mental health assessment of individual young people (and adults). The main features are:

    • Introduction of a persistent individual identification (PlusIID) for the person who is the subject of multiple assessments.
    • Uses the familiar, paper-based SDQscore for longitudinal assessment around the PlusIID.
    • Self-entry of SDQ assessments on PCs, laptops, iPads and mobile phones. Invitations may be sent via email for the person, parents and teachers to complete. Deutsch, English, Español, Français, Hrvatski, Português, Русский and Svenska are supported.
    • Integration of the data from all assessments and diagnoses into a single summary “visualisation”, ordered chronologically.
    • Ability to create groups of PlusIIDs and conduct SDQ assessment within SDQcohort.
    • A full range of APIs to allow organisations to integrate SDQplus into their systems (EHR, CMS, SMS).

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