The 18-item Swedish version of Ryff’s psychological wellbeing scale : psychometric properties based on classical test theory and item response theory
Background: Psychological wellbeing is conceptualized as the full engagement and optimal performance in existential challenges of life. Our understanding of psychological wellbeing is important for us humans to survive, adapt, and thrive during the challenges of the 21st century. Hence, the measurement of psychological wellbeing is one cornerstone for the identification and treatment of both menta
