Kessler Psychological Distress Scale (K5)
What it is
The K5 is a brief 5-item self-report measure of non-specific psychological distress. It assesses the frequency of symptoms associated with anxiety and depression, and is primarily used as a population-level screening tool and for routine monitoring of emotional wellbeing. The K5 was derived from the widely used 10-item Kessler Psychological Distress Scale (K10) and retains its core elements in a shorter format.
The K5 is a non-specific measure — it assesses psychological distress in general rather than targeting a particular diagnosis. It is well suited to use in settings where brevity is important, and as an indicator of whether further assessment may be warranted.
How is it used
- Suitable for adults aged 18 and over
- Takes approximately 2–3 minutes to complete
- Asks about the frequency of distress symptoms (e.g. feeling nervous, hopeless, restless, sad, or that everything is an effort) over the past four weeks
- Used as a screening indicator, to monitor changes over time, and to evaluate the impact of treatment
- Can be integrated into routine assessment alongside other measures focused on specific conditions
What do the scores mean?
Each item is rated on a five-point frequency scale from 1 (none of the time) to 5 (all of the time), giving a total score range of 5 to 25. Higher scores indicate greater psychological distress.
- Score of 5–10: Low or no significant distress
- Score of 11 or above: Indicative of clinically significant psychological distress, consistent with symptoms of depression or anxiety that may benefit from further assessment or support (Brinckley et al., 2021)
The K5 demonstrates strong internal consistency (Cronbach's alpha .85–.89) and a unidimensional factor structure, with approximately 70% of variance attributable to a single factor. It has also shown good convergent validity, with higher scores associated with poorer quality of life and greater self-reported mental health difficulties.
Developer
The K5 is derived from the K10, which was developed by Professor Ronald C. Kessler at Harvard University as part of the National Health Interview Survey (Kessler & Mroczek, 1992).
References:
Kessler, R. C., & Mroczek, D. (1992). An update of the development of mental health screening scales for the US National Health Interview Study. Ann Arbor, MI: Survey Research Center of the Institute for Social Research, University of Michigan.
Brinckley, M., Ritte, R., Allender, S., Brown, A., & Canuto, K. (2021). Reliability, validity, and clinical utility of a culturally modified Kessler scale (MK-K5) in the Aboriginal and Torres Strait Islander population. BMC Public Health, 21, 1094.