Case Study

Your office is reviewing its disease screening policies and procedures, and you wonder if depression screening should be included. You are concerned about the effectiveness of screening, your partners' comfort with depression diagnosis and treatment, and the amount of time screening would take.

Case Study Questions

1. Which one of the following statements best reflects the recommendations of the U.S. Preventive Services Task Force (USPSTF) regarding screening for depression in primary care settings?

• A. Screening for depression is recommended for adolescents and adults.

• B. Screening for depression is recommended for children, adolescents, and adults in clinical practices that have systems in place for diagnosis, treatment, and follow-up.

• C. Screening for depression is recommended for adults in clinical practices that have systems in place for diagnosis, treatment, and follow-up.

• D. There is insufficient evidence to recommend for or against screening for depression in any patient population unless a patient has risk factors.

• E. There is insufficient evidence to recommend for or against screening for depression in any patient population, although clinicians should remain alert to possible signs of depression in their patients.

2. During a staff meeting, the following comments about depression screening are made. Which statements are accurate?

• A. The office should establish an alliance with a psychiatrist before initiating a screening program.

• B. Asking just two questions can be an effective depression screen.

• C. For improved accuracy, all clinicians should be encouraged to select the same screening tool.

• D. An office that decides to initiate screening for depression should be prepared for a commitment beyond the time involved in screening.

3. Your colleagues elect to initiate a screening program for depression. Which one of the following responses is the best choice for a patient who screens positive for depression?

• A. Offer antidepressant medication.

• B. Refer directly to a psychiatrist or other mental health clinician.

• C. Schedule a full diagnostic interview.

• D. Probe for life stressors that may have prompted alterations in mood.

• E. Identify risk factors for depression.

Answers

1. The correct answer is C. The USPSTF recommends screening adults for depression in primary care settings that have systems in place to assure accurate diagnosis, effective treatment, and careful follow-up. The prevalence of major depression has been found to be 5 to 15 percent in primary care settings, and up to 50 percent of depressed patients are not diagnosed. Many risk factors for depression (e.g., female gender, family history of depression, unemployment, chronic disease) are common, but the presence of risk factors alone cannot differentiate depressed and non-depressed patients. Screening also has the potential to identify other disabling depressive illnesses, such as dysthymia (chronic low-grade depression) and minor depression (episodic, less severe illness), which are as common as major depression in primary care settings. Among adults, the optimal interval for screening is unknown. Recurrent screening may be most productive in patients with a history of depression, unexplained somatic symptoms, comorbid psychologic conditions (e.g., panic disorder, generalized anxiety), substance abuse, or chronic pain.

The USPSTF found limited evidence on the accuracy and reliability of screening tests in children and adolescents, and limited evidence on the effectiveness of therapy in children and adolescents identified through routine screening for depression in primary care settings. Screening instruments have been tested in children and adolescents, with sensitivity and specificity similar to those for adults. However, because the underlying prevalence of depression is much lower in children (0.5 to 2.5 percent in children and 0.4 to 6.4 percent in adolescents), the positive predictive value of screening is low. Because of these factors, the USPSTF does not recommend either for or against routine screening of children or adolescents for depression, although clinicians should remain alert for possible signs of depression in younger patients.

2. The correct answers are B and D. Many formal screening tools are available for depression screening in primary care. However, asking two simple questions about mood and anhedonia (i.e., “Over the past two weeks, have you felt down, depressed, or hopeless?” and “Over the past two weeks, have you felt little interest or pleasure in doing things?”) may be as effective. There is little evidence to recommend one screening method over another, so clinicians can choose the method that best fits their personal preference, the patient population, and the practice setting.

The time commitment involved in administering screening is only part of the investment. Clinical practices that screen for depression should have systems in place to ensure that positive screening results are followed by accurate diagnosis, effective treatment, and careful follow-up. Several randomized controlled trials have examined the effectiveness of screening for depression in primary care settings. Three trials that compared the effects of integrated recognition and management programs with “usual care” in community primary care practices showed improved patient outcomes. Integrated programs included feedback, provider and/or patient education, access to case management and/or mental health care, telephone follow-up, and institutional commitment to quality improvement. All three trials required allocation of clinic resources to detection and management programs.

3. The correct answer is C. A positive depression screening test should be followed up with a diagnostic interview (using diagnostic criteria from the Diagnostic and Statistical Manual of Mental Disorders, fourth edition) to determine the presence or absence of specific depressive disorders. Given the high rate of depression in the population, about 24 to 50 percent of patients who screen positive will have major depression. Those who screen “false positive” may have dysthymia or subsyndromal depressive disorders that might benefit from treatment or closer monitoring; others may have comorbid disorders such as anxiety disorder, substance abuse, panic disorder, post-traumatic stress disorder, or grief reactions. False-negative rates of most screening instruments are 10 to 20 percent.