PHILADELPHIA (AP) -- A federal task force recommended that all adults be screened for depression during regular visits with their doctors, saying as many as half of all cases are missed and others are mistreated.

An estimated 20 million Americans suffer from depression, and the U.S. Preventive Services Task Force said the nation's primary care doctors could begin to identify as much as 90 percent of cases by asking questions about depression.

The task force, an independent medical panel asked by the federal government to evaluate the latest research in deciding what routine medical screening Americans need, released the findings in Tuesday's edition of the Annals of Internal Medicine.

The task force said it recommends screening adults for depression in clinical settings that allow for effective treatment and follow-up.

They said doctors should start by asking patients two questions: "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?"

A yes answer to either question should be followed with in-depth questionnaires to determine whether the patient is depressed, the panel said.

The panel declined to make a recommendation for or against routine screening of children or adolescents for depression, citing insufficient evidence about the reliability and accuracy of such tests in young people.

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