Normative Values and Psychometric Properties of the Penn State Worry Questionnaire in Substance Use Disorder Treatment Population

This study evaluated the Penn State Worry Questionnaire (PSWQ) as a tool for measuring worry and anxiety levels among individuals entering treatment for substance use disorders (SUDs). The sample included 75,047 individuals admitted to SUD treatment centers, with assessments conducted weekly. Individuals entering SUD treatment exhibited higher baseline levels of worry; however, worry levels declined over the course of treatment. The PSWQ demonstrated good internal consistency, high test-retest reliability, and good discriminant validity when correlated with measures of depression and stress. The factor structure analysis confirmed that the PSWQ measures the same underlying construct of worry in the SUD treatment population, with a single-factor model showing satisfactory fit. This extends the reach of the PSWQ to the SUD treatment population by reaffirming its reliability, validity, and factor structure, with the expectation of higher levels of worry compared to a non-SUD population at the beginning of treatment, which decline over time.