Reliability and validity study of the Turkish version of the remission from depression questionnaire

Objective: In current psychiatric practice, the principal goal in the treatment of patients with Major Depressive Disorder (MDD) is to achieve remission. Symptom-based definitions of remission do not adequately reflect the treatment expectations of depressed patients. The “Remission from Depression Questionnaire (RDQ)” evaluates not only symptoms of depression but also patients’ other psychiatric symptoms, positive mental health, ability to function in various contexts, sense of well-being, life satisfaction and ability to cope. The first aim of this study is to assess the reliability and validity of the RDQ’s Turkish language version. Secondly, it purposes to compare the scale with the Hamilton Depression Rating Scale (HDRS) and the Beck Depression Inventory (BDI) in psychometric terms.

Method: 106 outpatients who met MDD diagnosis criteria according to Diasnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) were included in the study. After the translation and back-translation processes, the RDQ, HDRS, BDI, Beck Anxiety Inventory and World Health Organization Quality of Life survey (short version) were administered.

Results: All item-scale correlations were found to be statistically significant, and the median value for correlations was .534. The RDQ Turkish version demostrated excellent internal consistency with Cronbach’s alpha coefficient of .945. The test-retest reliability value for the overall RDQ was .908. The correlations between the RDQ subscales and psychosocial functioning, quality of life areas, anxiety severity and depression severity were evaluated and convergent validity analysis was performed, revealing significant relationships between the RDQ total and subscale scores and the other applied scales. For a discriminant validity assessment, the RDQ scores and subscales of two groups made up of the patients who were in remission and those who were not in remission were compared with the HDRS score (with a cutoff point of 7 points) or BDI (with a cutoff point of 17 points) score. We conducted a ROC curve analysis to determine the most appropriate cutoff score for the RDQ. When the cutoff value 7 of HDRS were used, sensitivity was found to be 86.7% for a cutoff value of 43 for the RDQ, and specificity was 73.5%. When the cutoff value 17 of BDI were used, the sensitivity was 85.5% and the specificity was 75% for a cutoff value of 43 for the RDQ.

Conclusion: Our findings show that the Turkish version of RDQ is a reliable and valid scale.