To therapists anyone concerned with it,
A colleague of mine recently had a paper accepted by Journal of Clinical Psychiatry with some interesting information on the PHQ-9. I copied the abstract below, but here are some of the highlights. When comparing the depression severity ranges between the PHQ-9, QIDS, CUDOS, and HAM-D in a sample of 245 outpatients who had been diagnosed with MDD, he found that the majority scored in the moderate range on the CUDOS and HAM-D whereas a majority scored as severe based on the PHQ-9 and QIDS. The PHQ-9 also had significantly more patients scoring in the severely depressed range compared to the QIDS. Among patients rated as mildly depressed on the HAM-D, one quarter scored in the severely depressed range on the QIDS, and one third scored in the severely depressed range on the PHQ-9.
Until I had read my colleague’s paper, I was not aware that the DSM-5 Depressive Disorders Workgroup is recommending using the PHQ-9 as a preferred measure. In light of my colleague’s findings, I wondered if perhaps there might be some unintended consequences to using the PHQ-9 with respect to treatment recommendations. As noted in my colleague’s paper, NICE guidelines recommend psychotherapy as a first-line treatment for mild depression, and pharmacotherapy with psychotherapy is recommended for moderate and severe depression. If a greater proportion of patients would be classified as severely depressed based on the PHQ-9 compared to other measures, I wonder if this could have consequences for psychotherapy being less likely to be recommended as a treatment option? Do others have thoughts on this? Please comment on this on the DSM 5 website. http://www.dsm5.org/Pages/Default.aspx
Zimmerman, M., Martinez, J., Friedman, M., Boerescu, D.A., Attiullah, N., Toba, C. (in press). How Can We Use Depression Severity to Guide Treatment Selection When Measures of Depression Categorize Patients Differently? Journal of Clinical Psychiatry
Objective: Treatment guidelines for depression suggest that severity should be taken into account when initiating treatment. If clinicians are to consider illness severity in selecting among treatment options for depression then it is important to have reliable, valid, and clinically useful methods of distinguishing between levels of depression severity. In the present report from the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project we compared three self-report scales assessing the DSM-IV criteria for major depression in the distribution of patients into severity categories.
Methods: Two hundred forty-five depressed outpatients completed the Clinically Useful Depression Outcome Scale (CUDOS), Quick Inventory of Depressive Symptomatology (QIDS), and Patient Health Questionnaire (PHQ-9). The patients were subdivided into severity categories according to the cutoff scores recommended by each scales’ developers. The patients were also rated on the 17-item Hamilton Depression Rating Scale (HAMD).
Results: The correlations between the HAMD and the 3 self-report scales were nearly identical. Yet, the scales significantly differed in their distribution of patients into severity categories. On the CUDOS and HAMD moderate depression was the most frequent severity category, whereas on the PHQ-9 and QIDS the majority of the patients were classified as severe. Significantly fewer patients were classified severely depressed on the CUDOS compared to the PHQ-9 (p<.001) and QIDS (p<.001).
Discussion: If clinicians are to follow treatment guidelines’ recommendations to base initial treatment selection on the severity of depression, then it is important to have a consistent method of determining depression severity. The marked disparity between standardized scales in the classification of depressed outpatients into severity groups indicates that there is a problem with the use of such instruments to classify depression severity. Caution is warranted in the use of these scales to guide treatment selection until the thresholds to define severity ranges have been empirically established.