Description
The SDS comprises 20 items; ten are worded positively and ten negatively. For each item, respondents indicate the frequency with which they experience the symptom or feeling, either at the time of testing (7) or in the previous week (4). The 1974 version of the scale, slightly modified from the original (5), is shown in Exhibit 7.1 (4, Table 21.2; 6, Table 3). Note that there is an error in item 13 in the version printed in reference (4); the version shown in Exhibit 7.1 is correct. The scale takes ten to 15 minutes to complete, according to the patient’s age and condition (8, p364).