The goal of this study was to establish whether the SSST, a Serbian language scrambled sentences instrument, is a reliable measure of depressive cognitive bias, and whether it captures the suppression tendency as participants exert the additional cognitive effort of memorizing a six-digit number while completing the task. The sample consisted of 1071 students, randomly assigned into two groups. They completed the SSST divided into two blocks of 28 sentences, together with additional cognitive task during either the first or second block, and after that a number of instruments to establish validity of the SSST. The test was shown to be a reliable instrument of depressive cognitive bias. As a measure of suppression the SSST performed partly as expected, only when load was applied in the second half of the test, and fatigue and cognitive effort enhanced suppression. The advantages of the test versus self-description measures were discussed. [Projekat Ministarstva nauke Republike Srbije, br. 179006: Hereditary, environmental, and psychological factors of mental health]