K10 / K6 Psychological Distress Scale

Introduction

The Kessler Psychological Distress Scale (K10/K6) was developed by Ronald Kessler and colleagues to screen for non-specific psychological distress. The K6 is the short form used in the US National Health Interview Survey and the WHO World Mental Health Survey.

Both versions ask how often you experienced 6 or 10 symptoms during the past 30 days. Higher scores indicate higher distress and a greater likelihood of meeting criteria for a mental health condition.

What do the K10 and K6 measure?

The Kessler scales — K10 with ten items and K6 with six — are the world's most widely used screens for non-specific psychological distress. They ask how often, during the last 30 days, you experienced states like nervousness, hopelessness, restlessness, sadness, and effortful calm. They were built for population health surveys, which is exactly why they are short and neutral: they measure recent distress, not any particular disorder.

How the questionnaire works

You choose how often you felt each way during the past 30 days, from none of the time to all of the time. The K10 asks about ten experiences; the K6 condenses them to the six most informative ones. Answer for the whole 30-day window, not for today. It takes one to two minutes, and nothing is uploaded.

How to read your result

Your total falls into one of four bands, from likely low distress to severe. The bands describe the level of distress you reported for one month — they are not diagnoses, and they do not say why the distress is there. A bad month follows bereavements, exams, illness, and ordinary life; the bands are most useful as a snapshot to compare against other months and as a prompt for what to do next.

What these screens cannot do

The K10 and K6 measure non-specific distress: they cannot tell which condition, if any, underlies it, and they cannot replace clinical assessment. The 30-day window means they deliberately miss longer-past episodes. How people report inner states also varies between cultures. A high band is a reason to talk to a professional — not a label to keep.

References

• Kessler, R.C., Andrews, G., Colpe, L.J., Hiripi, E., Mroczek, D.K., Normand, S.L., et al. (2002). Short screening scales to monitor population prevalences and trends in non-specific psychological distress. Psychological Medicine, 32(6), 959-976. DOI: https://doi.org/10.1017/S0033291702006074
• Kessler, R.C., Barker, P.R., Colpe, L.J., Epstein, J.F., Gfroerer, J.C., Hiripi, E., et al. (2003). Screening for serious mental illness in the general population. Archives of General Psychiatry, 60(2), 184-189. DOI: https://doi.org/10.1001/archpsyc.60.2.184