7 Tools to Identify Depression

In addition, a yes to Question 9, which asks about thoughts of self-harm and/or suicide, is also diagnostic.

The healthcare provider is instructed to follow up the checklist with an interview to verify the answers and to place the answers in context. Studies have demonstrated that a cut-off score of 10 or higher yields a sensitivity of 88% and a specificity of 88% for major depression.²⁸ Of the nine items on the scale, three (energy, eating and sleep) are also present in people who have arthritis, which can make it problematic for use in this population.

A scaled down version of the PHQ-9 is the PHQ-2. This shorter version contains only two questions that are effective for performing a screen without rating the severity of the depression. It’s appropriate for use in a busy practice in which the provider must screen for and collect information about many health-related conditions.²⁹ In the PHQ-2, the two relevent questions ask for the frequency of two symptoms over the past week. They are having a depressed mood and loss of interest in activities. The possible scores run from 0–6. A cut-off score of 3 or greater yielded a sensitivity of 83% and a specificity of 92%. Further, as the scores increase, difficulty performing important life activities, such as going to work and healthcare use, increase.29 This two-question tool is as effective as longer screens and does not contain any questions that overlap with the symptoms of arthritis.

The PRIME-MD is another frequently used, validated tool to measure depression. It consists of 27 questions (see Table 3). However, it has been reported that a “yes” answer to one of two critical questions had 86% sensitivity and 75% specificity, compared with a subsequent telephone interview diagnosis of MDD.³⁰

Whooley et al carried out a study of 536 patients attending a VA hospital to determine the efficacy of using these two questions with a simultaneous interview to determine the sensitivity and specificity of the tool. Another goal of this study was to determine the validity of these two critical questions compared with six previously validated screens.

The two questions were selected because they asked for the essential features of MDD (depressed mood and loss of interest in activities), which occurred over a period of at least two weeks. The two questions selected from the PRIME-MD questionnaire are: 1) “During the past two weeks, have you often been bothered by feeling down, depressed or hopeless?” and 2) “During the past two weeks, have you often been bothered by having little interest or pleasure in doing things?”³⁰