Development and psychometric properties of the Emotional State Questionnaire, a self-report questionnaire for depression and anxiety

Anxiety and depression are dimensions of emotional state that can be validly assessed with self-report measures. This article introduces a new self-report questionnaire for depression and anxiety (Emotional State Questionnaire (EST-Q)) and presents data on its reliability and validity. The items of the EST-Q were derived from diagnostic criteria of DSM-IV and ICD-10. Thirty-three items were rated on a five-point frequency scale. The questionnaire was administered to 194 inpatients with depressive and anxiety disorders and to a population sample of 479 subjects. According to the results of factor analysis, five subscales were formed: Depression, Anxiety, Agoraphobia-Panic, Fatigue, and Insomnia. EST-Q and subscales showed acceptable internal consistency (alpha = 0.69-0.88). Significant differences in subscales between patients and population and across diagnostic groups confirmed the discriminant validity of the instrument. Depression, Anxiety, and Agoraphobia-Panic subscales distinguished corresponding diagnostic groups. Fatigue and Insomnia appeared to assess nonspecific psychopathology dimensions characteristic of several psychiatric disorders.