Reliability, validity, and factorial structure of the Turkish version of the Luebeck questionnaire for recording preoperational thinking (Turkish LQPT)

OBJECTIVE: The objective of the current study is to establish the psychometric properties and factorial validity of the Turkish version of the Luebeck Questionnaire for Recording Preoperational Thinking (LQPT) in a Turkish sample. METHODS: The study was conducted in Istanbul Metropolitan area and comprised of healthy controls (n = 33) and patients with psychiatric diagnoses (n = 60). Socio-demographic data of the participants were collected and the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I), the Dysfunctional Attitude Scale (DAS-A), and the LQPT were administered. RESULTS: The mean age of the study participants was 30.51 +/- 8.75; 64.5% (n = 60) of the participants were female; 35.5% (n = 33) were male. The LQPT scores were non-normally distributed. The Cronbach's alpha for the LQPT scale was found 0.887 and the split-half reliability coefficient was 0.902. The inter-item correlation was ranging from 0.189 to 0.705. A negative and statistically significant correlation was found between the Turkish LQPT and the DAS-A and its subscales. The principal-components analysis with Promax rotated solution yielded two factors which accounted for 46.43% of the total variance. CONCLUSIONS: Our results suggested that Turkish LQPT was a valid and reliable instrument with a robust factorial structure for tapping the cognitive components associated with the development of depression in clinical psychiatric populations in Turkey.