ADMINISTRATION

The patient is asked to rate the severity and frequency of specific symptoms present over the last 7 days. The clinician versions (IDS-C and QIDS-C) are completed by a clinician or trained rater. It takes approximately 10 to 15 minutes to administer the IDS-C, and 5 to 7 minutes to complete the QIDS-C. With repeated use, clinical experience reveals that these times become shorter.

The clinician proceeds through the items, asking the patient to report on each item of the IDS-C, or QIDS-C. The symptoms are familiar to clinicians, as the individual items are defined by the constructs represented in the DSM-V criteria for MDD. Each item is interval scaled from 0 to 3; 0 indicates absence of the symptom during the last 7 days. The anchors are intended to help raters represent the frequency and intensity associated with each item / symptom. An adjunctive semi-structured interview guide is available in the English and Spanish versions of the IDS-C and QIDS-C. They provide a set of standardized introductory questions and follow-up prompts that are helpful in standardizing test administration. The semi-structured interview format guides less clinically experienced test administrators in test administration, assuring the constructs underlying the items are queried in a consistent manner, thus allowing for a high degree of confidence in the interpretations and subsequent generalizability of the scores obtained.

When administering the self-report version, patients should be instructed to take their time, read each item carefully, read all the possible responses, and choose the item response (0, 1, 2, or 3) that best describes themselves over the last 7 days. The self-report versions (IDS-SR and QIDS-SR) should be completed in one sitting. Care should be taken to note if the patient is able to read the assessment effectively (i.e. uncorrected vision, literacy below 6th grade level). If patients are not able to confidently read the self-report versions, the clinician rated structured interview versions should be substituted, or the self-report can be read to the patient to assist him/her.

SCORING

When complete, the IDS-C and IDS-SR are scored by summing responses to 28 of the 30 items to obtain a total score ranging from 0 to 84. Either appetite increase or decrease, but not both, are used to calculate the total score. Weight increase or decrease, but not both, are used to calculate the total score (Rush et al. 1996).

The QIDS-C and the QIDS-SR total scores range from 0 to 27. The total score is obtained by adding the scores for each of the nine symptom domains of the DSM-IV MDD criteria: depressed mood, loss of interest or pleasure, concentration/decision making, self-outlook, suicidal ideation, energy/fatigability, sleep, weight/appetite change, and psychomotor changes (Rush et al. 2003). Sixteen items are used to rate the nine criterion symptom domains of a major depressive episode: 4 items are used to rate sleep disturbance (early, middle, and late insomnia plus hypersomnia); 2 items are used to rate psychomotor disturbance (agitation and retardation); 4 items are used to rate appetite/weight disturbance (appetite increase or decrease and weight increase or decrease). Only one item is used to rate the remaining 6 domains (depressed mood, decreased interest, decreased energy, worthlessness/guilt, concentration/decision making, and suicidal ideation). Each item is rated 0-3. For symptom domains that require more than one item, the highest score of the item relevant for each domain is taken. For example, if early insomnia is 0, middle insomnia is 1, late insomnia is 3, and hypersomnia is 0, the sleep disturbance domain is rated 3. The total score ranges from 0-27.