Screening is not diagnosis

What the questions measure

They are two short questionnaires used around the world. One asks nine questions about feeling down over the last two weeks, such as little interest in things, sadness, sleep and tiredness. The other asks seven questions about anxiety, such as worry that is hard to control, tension and restlessness. For each question, you say how often it happened.

Your answers become a level: low, mild, moderate or high. These levels come from the studies that created the questionnaires and were tested with thousands of people. The authors recommend a fuller assessment when the level reaches moderate or above.

Why it is not a diagnosis

A diagnosis is a clinical conclusion. It takes into account your history, how long the signs have been there, how much they get in the way of your life, other health conditions that could explain what you feel, and whatever else is going on. A questionnaire sees none of that.

In the original study of the questions about feeling down, a moderate level or above picked out about nine in ten people with major depression confirmed by a professional interview, and left out about nine in ten people without it. A 2019 analysis using data from more than seventeen thousand participants found similar numbers. These are good results for a screening, but they leave room for mistakes in both directions.

Another analysis, from 2020, showed how much room: among more than nine thousand people, about one in four had a moderate level or above, but only about one in eight met the criteria for major depression in a diagnostic interview with a professional. In other words, the answers alone tend to point to more cases than there really are.

What a high level means

A high level is a signal to talk to a professional, not a verdict. The US Preventive Services Task Force, which recommends screening adults for depression, makes clear that any result that stands out needs a further assessment to confirm the diagnosis and understand how severe it is.

The same goes for the last question about feeling down, about thoughts of death or of hurting yourself. Any answer other than "not at all" deserves attention, and the authors’ manual notes that properly assessing risk requires a clinical conversation. That is why the app shows help contacts whenever this happens.

What a low level means

A low level does not guarantee that all is well either. If you feel something has changed, if you are struggling or if people close to you are worried, it is worth seeking help, whatever the result.

What about other questionnaires?

Screening questionnaires exist for other conditions, such as bipolar disorder. Even so, NICE advises against using questionnaires in primary care to identify bipolar disorder in adults: the way forward is to ask about a person’s history of mood and refer them for a specialist assessment when there are signs. In the app we only use validated instruments whose licence and official translation allow it, and always as screening.

Using your answers well

Answer every two weeks, thinking about how things have really been. Look at the trend over time more than at any single result. Take your answers and your check-ins to the conversation with the professional who sees you; they help tell your story.