The relationship between severity of depressive symptoms, metacognitions and obsessive beliefs in patients with major depressive disorder

The aim of this thesis was to investigate the relationship between major depressive disorder and metacognitions and obsessive beliefs in Turkish sample and to contribute to the metacognitive research with data obtained from Turkey. In addition, other objectives of the study are assigning metacognitions and obsessive belief domains that play a role in depression. To achieve these goals, the study was conducted with 50 patients with major depressive disorder and 45 non-clinical subject. In order to more clearly represent differences between clinical and non-clinical groups, individuals with depression scores higher than 17 included in this study. After general information about the purpose of the study was given to all participants, the participants completed the related measurement tools. In this study, Beck Depression Inventory (BDI) was used to measure the severity of depressive symptoms, Obsessive Beliefs Questionnaire (OBQ-44) was used to determine obsessive beliefs, Metacognition questionnaire (MCQ-30) was used to evaluate metacognitions and Personal Information Form was used which included the personal information of the participants. The results about the thesis were examined under three main headings. In the first part, the scores obtained from the measurement instruments and subscales used in the study were examined according to the characteristics obtained from the personal information form. As a result of the analysis, there was no significant relationship between clinical and non-clinical participants' age at onset and scores obtained from the scales. In addition, it was found that the scores obtained from the scales of clinical and non-clinical participants did not differ according to gender. In the second part, the results related to whether the scores obtained from the scales and subscales used differ for the clinical and non-clinical participants are given as sub-headings. As a result of the analyzes, it was found that the scores obtained from the clinical and non-clinical groups differed for all scales and subscales. In the third and last chapter, the relationship between depression severity, metacognitive factors and obsessive beliefs were examined. All obsessive beliefs and all metacognitive beliefs were found to be related with depression. There was no significant relationship between cognitive insecurity, one of the metacognition factors, and none of the obsessive beliefs. In addition, there was no significant relationship between positive beliefs, one of the metacognitive factors and the importance/control of thoughts, which is one of the obsessive beliefs. The findings are compatible with the related literature findings in the field of clinical psychology and metacognitive model of depression. Keywords: Major depressive disorder, metacognition, obsessive beliefs