The Strengths and Difficulties Questionnaire (SDQ) is a self-report inventory behavioral screening questionnaire for children and adolescents ages 2 through 17 years old, developed by United Kingdom child psychiatrist Robert N. Goodman. The SDQ has been translated into more than 80 languages, including Spanish, Chinese, Russian, and Portuguese. Overall, the SDQ has been proven to have satisfactory construct and concurrent validity.There are three versions of the SDQ: a short form, a longer form with impact supplement, and a follow-up form designed for use after a behavioral intervention. The questionnaire takes 3–10 minutes to complete.