Development and validation of the Penn State Worry Questionnaire

Area of Science:

• Psychological assessment
• Clinical psychology
• Psychometrics

Background:

• Chronic worry is a core feature of generalized anxiety disorder (GAD).
• A validated instrument is needed to measure the trait of worry.
• Existing measures may not adequately capture the independent construct of worry.

Purpose of the Study:

• To develop and validate the Penn State Worry Questionnaire (PSWQ).
• To assess the psychometric properties of the PSWQ.
• To evaluate the PSWQ's ability to discriminate between diagnostic groups and measure treatment outcomes.

Main Methods:

• Factor analysis of a large item pool to develop the 16-item PSWQ.
• Internal consistency and test-retest reliability analyses.
• Correlational analyses with related and unrelated psychological measures.
• Group comparisons based on DSM-III-R criteria for GAD and PTSD.
• Treatment outcome study comparing cognitive therapy with nondirective therapy.

Main Results:

• The 16-item PSWQ demonstrated high internal consistency and good test-retest reliability.
• The PSWQ correlated predictably with worry-related measures and not with remote constructs.
• Responses were not influenced by social desirability.
• The PSWQ significantly discriminated between college samples meeting GAD criteria and those with PTSD.
• In GAD patients, the PSWQ was independent of other anxiety/depression measures and showed greater reduction with cognitive therapy.

Conclusions:

• The PSWQ is a psychometrically sound instrument for measuring the trait of worry.
• The PSWQ can differentiate between GAD and PTSD, and assess treatment efficacy.
• The PSWQ measures a construct independent of general anxiety and depression in clinical populations.