During trial-based cognitive therapy (TBCT), and after having familiarized the patient with the cognitive distortions by means of the distortions list, part of the session and sometimes a whole session is devoted to teaching the patient how she can assess and keep track of her cognitive distortions during the therapy course by means of the cognitive distortions questionnaire (CD-Quest). The CD-Quest is itself a distinctive feature of TBCT. The transcript discussed in this chapter provides an idea of how the therapist may introduce the CD-Quest to the patient named Julia. The chapter discusses cognitive distortions such as dichotomous thinking, fortune telling also called catastrophizing, discounting or disqualifying the positive, emotional reasoning, labeling, magnification/minimization, selective abstraction also called mental filter and tunnel vision, mind reading. These cognitive distortions are analysed with its definition, score, frequency intensity and how often it occurs.