K10

K10, also written as K-10, most commonly refers to the Kessler Psychological Distress Scale, a brief self-report screening instrument used to quantify non-specific psychological distress in the general population. The scale was developed by Ronald C. Kessler and colleagues in the early 2000s to provide a quick, reliable indicator of probable mental illness in settings where full diagnostic interviews are impractical. It is widely used in clinical practice, primary care, and epidemiological surveys, including national health surveys in several countries.

The K10 consists of 10 questions about anxiety and depressive symptoms experienced in the past four weeks. Each item is rated on a five-point scale from 1 (none of the time) to 5 (all of the time), yielding a total score from 10 to 50. Higher scores indicate greater distress. Cutoffs for bands such as low, moderate, high, and very high distress are used in practice, but the exact thresholds vary by population and purpose, and should be interpreted in context.

In terms of validity, the K10 shows good internal consistency and acceptable test-retest reliability across adult populations, and has been translated into many languages with validated versions. It is designed as a screening tool, not a diagnostic instrument; a high score suggests probable mood or anxiety disorders and should prompt further clinical assessment.

Limitations include cultural and linguistic factors, potential for under- or over-reporting, and its non-specific nature. It is commonly used as a quick gauge of population mental health and to monitor change over time.