Development and psychometric properties of the Cognitive Distortions Questionnaire for Adolescents (CD-Quest-T)

Abstract Introduction The Cognitive Distortions Questionnaire (CD-Quest) is an instrument that identifies logical errors or cognitive distortions and is used in trial-based cognitive therapy (TBCT). However, it had previously only been available for adults. Objectives To develop and validate a version of the CD-Quest for teens (CD-Quest-T) aged 11 to 17 years and test its psychometric properties. Method A total of 299 schoolchildren participated in the investigation. After content validity was assessed, the language was adapted for the target age group, and the length of the instrument was reduced to eight items (from the initial 15). Five cognitive therapists analyzed the content and structure of the items. Finally, to investigate the construct validity of the CD-Quest-T, the instrument was divided into a full scale and two subscales, which measure the frequency of the distortions and the intensity attributed to them, respectively. Results The overall internal consistency of the scale was α = 0.77, whereas subscale indices were α = 0.75 for the frequency scale and α = 0.73 for the intensity scale. Results from exploratory factor analysis and concurrent validity analysis indicated that the CD-Quest-T items have good psychometric properties and generate scores reliably. Conclusion The psychometric properties of the CD-Quest-T demonstrate its adequacy for measurement of cognitive distortions in adolescents.


Introduction
One of the intervention methods used in cognitivebehavioral therapy (CBT) consists of addressing automatic thoughts (ATs), which are non-deliberate, spontaneous, quick, and pre-conscious cognitions. ATs are closely related to health because they directly affect emotions and behaviors. Psychological disorders follow specific cognitive patterns, maintained by dysfunctional core beliefs (CBs). When activated, these can generate dysfunctional emotions and behaviors, potentially impairing the person's mental health and, consequently, their quality of life. 1,2 According to Beck, 3 events can be perceived distortedly. These perceptions are called cognitive distortions and, in excess, they can lead to emotional difficulties or exacerbate mental disorders, such as depression and anxiety.
The ways that adolescents interpret their life experiences shape their emotional reactions and behaviors. When a person's dysfunctional CBs influence these ideas, logical errors or cognitive distortions can occur intensely and frequently. There is therefore a need for instruments to identify and quantify possible cognitive distortions in this age group. The objective is to find ways to prevent activation of dysfunctional CBs, since they may cause more problematic information processing and, consequently, impair adolescents' healthy functioning (Table 1). 4,5 There are specific instruments for measuring ATs in the current scientific literature. One of these is the Cognitive Distortions Questionnaire (CD-Quest), which is aimed at the general population and is mainly used in trial-based cognitive therapy (TBCT). 6 It is also designed to identify cognitive errors to help patients in their daily task of identifying cognitive distortions and relating them to emotions and behaviors. It provides therapists with a quantitative measure for use in clinical follow-up. 6 The psychometric properties of the CD-Quest have been evaluated in Brazil, 7 the United States, 8,9 Australia, 10 Turkey, 11 and China. 12 Two studies have been conducted in Brazil to assess the psychometric properties of the adult version of the CD-Quest (one published 7 and another still under consideration for publication).  15 Discriminant validity was confirmed against the Levenson Self-Report Psychopathology Scale (LSRP). 16 18 and revised by Messer et al. 19 The CD-Quest-T is an adaptation of the original adult version of the CD-Quest, 6 which identifies both the frequency and intensity with which cognitive distortions occur during the week. It is an initial self-monitoring instrument that helps in the patient's psychoeducation and in understanding the distortions and errors a person may make in response to situations they experience.
Therefore, the objective of this study was to develop the adolescent version of the CD-Quest, adapting it to this age group's language.

Method
This study was conducted in two phases, as described below. The objective of the first phase was to adapt the CD-Quest for adolescents and the objective of the second phase was to analyze the psychometric properties of the CD-Quest-T (Table 2).

Phase 1 -Adaptation of the CD-Quest-T
The data for development of the CD-Quest-T were  (Table 3). After the CD-Quest-T had been designed, it was sent to five people who were not involved in the previous survey, and who agreed to accept the role of experts to assess the quality of item development. They were asked four questions about the items on the instrument:

Instruments
Besides the CD-Quest-T, two other scales were used in this study to provide information on criteria validity: the Children's Depression Inventory (CDI) 21  The SCARED-R is a questionnaire developed by Birmaher et al. 26

Data analysis
The CD-Quest-T's psychometric properties were analyzed using R software. In a first phase, the content validity index (CVI) was estimated for the total score items. The minimum CVI defined as necessary for the items was as recommended by Almanasreh et al. 30

Content validity
The One of the experts who analyzed the adapted version was a psychometrics specialist and four were cognitive-behavioral therapists. All of them agreed that each item presented was related to its corresponding dimension and they did not propose any changes regarding the intended objective of the instrument.
They also considered the language was adequate for the age group addressed in the study. The experts' consensus on their evaluation and descriptive analysis of the questionnaire was that each item would be represented by a CVI exceeding 0.80. The design and content of the items in the CD-Quest-T achieved a CVI of 1.00 between the experts, indicating optimal quality and it was not therefore necessary to remove any of the items or modify the original structure.

Concurrent validity
The concurrent validity of the CD-Quest-T was

Internal consistency analysis
Cronbach's α for internal consistency was calculated separately for the total score and for the frequency and intensity subscales. A Cronbach's α of 0.77 was found for the internal consistency of the entire questionnaire, while Cronbach's alphas of 0.75 and 0.73 were found for the frequency and intensity scales respectively, indicating good and adequate internal consistency in all measurement levels. 30 It should be noted that excluding any one item would not have resulted in variation in the overall Cronbach's α value (Table 4).  Given the hypotheses formulated, conclusion of development of the CD-Quest-T items and evaluation of its psychometric properties yielded satisfactory evidence of the functioning of its items and scores.
The results were similar to those found in the literature regarding the adult version of the CD-Quest as a unidimensional instrument. 7,9,11 However, future studies are needed to evaluate the scores' stability and also the instrument's sensitivity to clinical conditions. More