2.1.2. Study 2
insomnia, Insomnia
EVENTS
Participants completed the POMS 2 and the Euthymia Scale on the third pre-examination day and completed the Insomnia Severity Index (ISI), which is a self-rating questionnaire to assess the subjective severity of insomnia, on the first day of the test food period as baseline evaluations. Participants answered the POMS 2, Euthymia Scale, and ISI once a week during the 4-week test food period. Within 3 days after the final day of the fourth week, participants visited the study facility for a health check and saliva sample collection. Life events were recorded throughout the entire study period.The study period was set to 4 weeks, because 4 weeks of repeated intake was hypothesized to be long enough to overcome the placebo effect and detect the intervention effect, as a clinical trial that investigated the effect of GABA on the subjective mood state showed the declined placebo effect on the fourth week in the 12 weeks of the trial period and showed significant intervention effect on the fourth week [