Psychometric properties of an instrument for measuring threat/control-override symptoms

Threat/control-override symptoms refer to delusional persecutory thoughts and feelings of losing control over mind and body. The Threat/Control-Override Questionnaire (TCOQ) was developed to assess such symptoms, and the purpose of the present study was to examine the psychometric properties of this measure in nonclinical students (n = 759) and acute and stabilized psychotic patients (n = 111 and 33, respectively). Factor analysis of TCOQ data in students and acute psychotic patients yielded a two-factor solution, with components referring to "threat" and "control-override" symptoms. Internal consistency and test-retest reliability were satisfactory and concurrent and discriminant validity were shown by a meaningful pattern of correlations with other self-report and interview measures. Group comparisons showed that patients displayed significantly higher scores on the TCOQ than did the nonclinical students. Altogether, it can be concluded that the TCOQ is a reliable and valid index for assessing feelings of persecution and losing control.