The K10 questionnaire, explained

What is the K10?

The K10, short for the Kessler Psychological Distress Scale, is a 10-question questionnaire about how you've been feeling over the past 4 weeks. It gives a single measure of psychological distress, based on questions about nervousness, agitation, psychological fatigue and depression ^[7].

It measures "non-specific" distress. That means it doesn't point to one particular condition. It was designed to measure distress across the anxiety and depression spectrum ^[7].

The K10 is widely used in Australia. Beyond Blue describes it as an evidence-based assessment commonly used by Australian GPs and mental health professionals ^[10]. You can take it now with our free online mental health check.

Who developed the K10?

The K10 was developed by Professors Ronald Kessler and Daniel Mroczek for the US National Health Interview Survey ^[7]. They started with around 500 possible questions and used survey data to narrow them down, ending with a 10-question scale (the K10) and a 6-question version within it (the K6) ^[5]. The final scales were built using item response theory, a statistical method for choosing questions that separate people well across the range of distress ^[1].

Australia was involved from the start. The K10 was included in the 1997 Australian National Survey of Mental Health and Well-Being, with more than 10,000 adults taking part, and that survey provided much of the early evidence on what scores mean ^[1][3].

What are the 10 K10 questions?

Each question asks about the past 4 weeks ^[5][11].

This is the wording published by the Australian Bureau of Statistics and the Black Dog Institute ^[5][11].

How do you answer and score the K10?

For each question, you choose one of five answers ^[7][11]:

Add up your 10 scores. The total ranges from 10, if you answered "none of the time" to everything, to 50, if you answered "all of the time" to everything ^[7]. Low scores mean low distress and high scores mean high distress ^[7].

There's one skip rule. If you answer "none of the time" to question 2 (nervous), question 3 isn't asked and automatically scores 1. The same goes for question 5 (restless or fidgety) and question 6 ^[6][11]. If you haven't felt nervous at all, you can't have felt so nervous that nothing could calm you down.

What does my K10 score mean?

There's no single official set of K10 cut-offs. When the ABS reviewed this, it noted the scale's creators hadn't published scoring cut-offs, and that Australian organisations had used several different versions ^[5]. The bands used in ABS national health surveys are ^[7]:

The ABS says a very high level of distress may indicate a need for professional help ^[7]. According to the ABS, these four bands combine research by Andrews and Slade (2001) with another Australian study ^[5].

Another set, used in the 2001 Victorian Population Health Survey and based on how practitioners use the K10 as a screening tool, is framed around how likely someone is to have a mental disorder: 10 to 19 likely to be well, 20 to 24 likely to have a mild disorder, 25 to 29 likely to have a moderate disorder, and 30 to 50 likely to have a severe disorder ^[5]. That's why the same score can be described differently in different places. Neither set is a diagnosis.

What Australian research shows

Andrews and Slade looked at K10 scores from 10,641 adults in the 1997 national survey ^[3]. About 68% scored under 15, and about 3% scored 30 or more ^[3].

The higher the score, the more likely someone was to meet criteria for a current mental disorder. In that survey, this was true of about 5% of people scoring 10 to 14, about 36% of those scoring 20 to 24, about 59% at 25 to 29 and about 76% at 30 to 34 ^[3].

More recently, the ABS 2022 National Health Survey found that 14% of Australian adults had high or very high psychological distress ^[8].

How is the K10 used in Australia?

• National health surveys. The ABS has used the K10 since the 1997 National Survey of Mental Health and Wellbeing, and in National Health Surveys from 2001 ^[7].
• Mental health care plans. When a GP prepares a Mental Health Treatment Plan, Medicare requires an outcome measurement tool unless it's clinically inappropriate, and the K10 is one of the examples given ^[9]. Our mental health care plan guide explains how plans work.
• Tracking change over time. Outcome tools like the K10 are used to monitor how your health changes in response to treatment, so a GP or psychologist may ask you to repeat it ^[9].
• Online self-checks. Beyond Blue runs an online K10 and makes clear it won't diagnose you ^[10].

How accurate is the K10?

For a 10-question screen, the K10 performs well in research, with some important trade-offs.

• Telling people with and without a disorder apart. In the original development work, the K10 and K6 strongly separated people with and without a DSM-IV disorder. The area under the curve (where 1.0 is perfect and 0.5 is chance) was 0.87 to 0.88 for disorders causing some impairment, and 0.95 to 0.96 for more severe ones ^[1].
• In Australia. In the Australian national survey, the K10's area under the curve for detecting mood and anxiety disorders was 0.90, better than the older GHQ-12 questionnaire at 0.80 ^[4].
• Serious mental illness. A US study found an area under the curve of 0.85 for the K10 in screening for serious mental illness ^[2].
• Consistency. A 2024 meta-analysis of 48 studies found high internal consistency for the K10, with an average Cronbach's alpha of 0.90 ^[13].

The trade-off is between catching everyone and avoiding false alarms. In Andrews and Slade's analysis, a cut-off of 16 picked up 86% of people with a current anxiety or mood disorder, but also flagged 22% of people without one ^[3]. A cut-off of 30 flagged almost nobody without a disorder (specificity 0.99), but picked up only 24% of people who had one ^[3].

Newer screeners are also being tested. One Australian study found a 5-question tool, the Distress Questionnaire-5, was more accurate than the K6 for each of the common disorders it examined except major depression, where there was no significant difference ^[14].

What the K10 can't tell you

• It isn't a diagnosis. Psychological distress isn't a diagnosis of mental illness ^[8], and only a health professional can diagnose you ^[10].
• It's a snapshot. It only covers the past 4 weeks ^[7], so your score can change as your circumstances do.
• A low score doesn't rule out a problem. Even at a cut-off of 16, about 1 in 7 people with a current anxiety or mood disorder scored below it ^[3].
• It doesn't cover everything. It doesn't include questions to identify psychosis ^[5], and none of the 10 questions ask about thoughts of suicide or self-harm.
• It's for individuals. Beyond Blue notes the K10 isn't recommended for group screening and isn't appropriate in a classroom setting ^[10].

If you're worried about how you've been feeling, your feelings matter whatever your score is.

Where can I get a K10 PDF?

If you'd like a printable K10 questionnaire or K10 assessment PDF, the Black Dog Institute publishes a free version with the questions and scoring notes. It can be downloaded and shared for non-commercial use, as long as the content isn't changed ^[11]. The ABS also publishes the full question wording ^[5].

The K10 itself carries a copyright notice in the name of Ronald C. Kessler, and Harvard's National Comorbidity Survey asks that the copyright be acknowledged and the 2003 paper by Kessler and colleagues be cited ^[2][12].

To do it online instead, use our free mental health check, which is based on the K10.

Are there shorter versions of the K10?

• K6. A 6-question version made up of questions from within the K10 ^[1]. It's used in health surveys in the United States and other countries ^[1].
• K5. A 5-question version that has been studied with Aboriginal and Torres Strait Islander people. In a large NSW study of people aged 45 and over, the K5 and K10 classified distress in Aboriginal participants very similarly ^[15].

When to see a GP about your K10 score

If your score is in the high or very high range, or you've just not felt like yourself for a while, it's worth talking to a GP. A GP can look at the whole picture, work out what's driving how you feel and talk through options with you. That might include support for anxiety or depression.

You can book a video mental health assessment with one of our Australian GPs. It's about an hour, and treatment can start from that appointment if your GP thinks it's right for you. To get started, request an appointment and our team will contact you to book.

If you're in crisis or thinking about suicide, call Lifeline on 13 11 14 or 000 in an emergency. Our urgent help page lists more support services.

This page is general information, not medical advice.