Pittsburgh Sleep Quality Index (PSQI)

The Pittsburgh Sleep Quality Index is a 19-item self-report questionnaire that scores a person's overall sleep quality over the previous month.

Its questions are grouped into seven components: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication and daytime dysfunction. Each component is scored from zero to three, and the components are summed to a global score from zero to 21, with higher scores meaning worse sleep; a global score above five is the conventional cutoff for poor sleep. The instrument takes about five to ten minutes and has been translated and validated in many languages, which is why it appears so widely in research across medicine, psychiatry and psychology.

The PSQI captures the person's perception, so it does not always agree with actigraphy or polysomnography, and its month-long window makes it less sensitive to short-term change than the Insomnia Severity Index, which covers two weeks. It also does not diagnose a specific sleep disorder; a high score prompts further evaluation. Readers meet the PSQI in cannabinoid sleep studies, where it is one of the most frequently reported outcomes. Those studies have generally been small, short and inconsistent, and no cannabinoid has an approved use for poor sleep quality.