In nonpsychotic MDD outpatients without overt cognitive impairment, clinician assessment of depression severity using either the QIDS-C16 or HRSD17 may be successfully replaced by either the self-report or IVR version of the QIDS.

The 17-item Hamilton Rating Scale for Depression (HRSD 17 ) and the Montgomery Äsberg Depression Rating Scale (MADRS) are two widely used clinicianrated symptom scales. A 6-item version of the HRSD (HRSD 6 ) was created by Bech to address the psychometric limitations of the HRSD 17 . The psychometric properties of these measures were compared using classical test theory (CTT) and item response theory (IRT) methods. IRT methods were used to equate total scores on any two scales. Data from two distinctly different outpatient studies of nonpsychotic major depression: a 12-month study of highly treatment-resistant patients (n=233) and an 8-week acute phase drug treatment trial (n=985) were used for robustness of results.MADRS and HRSD 6 items generally contributed more to the measurement of depression than HRSD 17 items as shown by higher item-total correlations and higher IRT slope parameters. The MADRS and HRSD 6 were unifactorial while the HRSD 17 contained 2 factors. The MADRS showed about twice the precision in estimating depression as either the HRSD 17 or HRSD 6 for average severity of depression. An HRSD 17 of 7 corresponded to an 8 or 9 on the MADRS and 4 on the HRSD 6 .The MADRS would be superior to the HRSD 17 in the conduct of clinical trials.

The clinical features of postpartum depression and depression occurring outside of the postpartum period have rarely been compared. The 16-item Quick Inventory of Depressive Symptomatology-Self-Report (QIDS-SR 16 ) provides a means to assess core depressive symptoms. Item response theory and classical test theory analyses were conducted to examine differences between postpartum (n 5 95) and nonpostpartum (n 5 50) women using the QIDS-SR 16 . The two groups of females were matched on the basis of age. All met DSM-IV criteria for nonpsychotic major depressive disorder. Low energy level and restlessness/ agitation were major characteristics of depression in both groups. The nonpostpartum group reported more sad mood, more suicidal ideation, and more reduced interest. In contrast, for postpartum depression sad mood was less prominent, while psychomotor symptoms (restlessness/agitation) and impaired concentration/decision-making were most prominent. These symptomatic differences between postpartum and other depressives suggest the need to include agitation/restlessness and impaired concentration/decision-making among screening questions for postpartum depression. Depression and Anxiety

This article addresses the issue of how to detect item preknowledge using item response time data in two computer-based large-scale licensure examinations. Item preknowledge is indicated by an unexpected short response time and a correct response. Two samples were used for detecting item preknowledge for each examination. The first sample was from the early stage of the operational test and was used for item calibration. The second sample was from the late stage of the operational test, which may feature item preknowledge. The purpose of this research was to explore whether there was evidence of item preknowledge and compromised items in the second sample using the parameters estimated from the first sample. The results showed that for one nonadaptive operational examination, two items (of 111) were potentially exposed, and two candidates (of 1,172) showed some indications of preknowledge on multiple items. For another licensure examination that featured computerized adaptive testing, there was no indication of item preknowledge or compromised items. Implications for detected aberrant examinees and compromised items are discussed in the article.

Objectives-Recent work using classical test theory (CTT) and item response theory (IRT) has found that the self-report ) and clinician-rated (QIDS-C 16 ) versions of the 16-item Quick Inventory of Depressive Symptomatology were generally comparable in outpatients with nonpsychotic major depressive disorder (MDD). This report extends this comparison to a less welleducated, more treatment-resistant sample that included more ethnic/racial minorities using IRT and selected classical test analyses. 16 and QIDS-C 16 were obtained in a sample of 441 outpatients with nonpsychotic MDD seen in the public sector in the Texas Medication Algorithm Project (TMAP). The Samejima graded response IRT model was used to compare the QIDS-SR 16 and QIDS-C 16 . 16 and QIDS-C 16 related well to overall depression. The slopes of the item response functions a), which index the strength of relationship between overall depression and each symptom, were extremely similar with the two measures. Likewise, the CTT and IRT indices of symptom frequency (item means and locations of the item response functions, b i ) were also similar with these two measures. For example, sad mood and difficulty with concentration/decision making were highly related to the overall depression severity with both the QIDS-C 16 and QIDS-SR 16 . Likewise, sleeping difficulties were commonly reported, even though they were not as strongly related to overall magnitude of depression. Methods-The QIDS-SR Results-The nine symptom domains in the QIDS-SR Conclusion-In this less educated, socially disadvantaged sample, differences between the QIDS-C 16 and QIDS-SR 16 were minor. The QIDS-SR 16 is a satisfactory substitute for the more timeconsuming QIDS-C 16 in a broad range of adult, nonpsychotic, depressed outpatients. KeywordsQuick Inventory of Depressive Symptomatology; Inventory of Depressive Symptomatology; Item response theory; Samejima graded response model; depressive symptoms OBJECTIVESThe accurate, rapid, and cost-efficient measurement of depressive symptoms serves both clinical and research purposes. Clinicians can gauge the benefit of treatment and make timely adjustments in the treatment plan. Research, on the other hand, can be made less costly if such measures are available. The Quick Inventory of Depressive Symptomatology (QIDS) is a 16-item scale that measures each of the nine symptom domains that define a major depressive , which defines depression as a latent trait, were employed. The particular IRT model we employed was developed by Samejima (1969Samejima ( , 1997 to examine graded responses. The recent study (Rush et al. in press) focused on a subset of patients with nonpsychotic major depressive disorder (MDD) derived from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial (Fava et al. 2003;Rush et al. 2004a). These patients were reasonably well educated as a group and were drawn from both primary and psychiatric care settings. They were selected to not be treatment resistant. Results were generally comparable between...