Clinical Research Directory

The inclusion criteria were as follows: (i) Chinese Hong Kong residents who were able to read Chinese; (ii) age 35 to 64 years; (iii) peri-menopausal women, defined as menstrual cycle irregularity (a change of 7 days or more in the menstrual cycle) or amenorrhea for no longer than 60 consecutive days, according to the recommendations from the Stages of Reproductive Aging Workshop; and (iv) with a current clinical DSM-5 diagnosis of insomnia disorder according to the Brief Insomnia Questionnaire. The criteria included having difficulties falling asleep, staying asleep, or early morning awakening with clinically significant consequences for daily life for at least 3 months. (v) An Insomnia Severity Index total score of at least 10 indicated that insomnia was present at the clinical level and (vi) Able to understand Chinese and Cantonese or Mandarin; (vii) willing to give informed consent and comply with the trial protocol. For (iv) and (v), both the Brief Insomnia Questionnaire and Insomnia Severity Index were included as inclusion criteria. This is because the two scales have different purposes. Specifically, Brief Insomnia Questionnaire is used to confirm the participants fulfil the diagnostic criteria of DSM-5 insomnia disorder, while the Insomnia Severity Index is used to assess the severity of the insomnia symptoms and related daytime impairments. The exclusion criteria are: (i) pregnancy; (ii) at significant suicide risk according to the rating by the Hamilton Depression Rating Scale item on suicide (score ≥3); (iii) no comorbid sleep disorders primarily requiring other treatments, such as sleep apnea or narcolepsy; (iv) change in the dose of their psychotropic drugs within 12 weeks prior to baseline, which would possibly indicate instability in their psychiatric condition; and (v) taking any antibiotics in 3 months before the baseline or any food containing probiotics, such as yogurt, in 7 days before the baseline.