The study had a crossover design implying that every patient underwent two different treatment courses in random sequence: hypnotic or structured educational program (BBT-I) delivered in two sessions.
Each treatment course was separated by 2-weeks washout period that provided the opportunity to evaluate the sustainability of treatment effect.
Before and after each treatment course and after each washout period subjects completed set of questionnaires.
The total duration of the study was 8 weeks in which 6 visits including 1 night polysomnography (PSG), 2 face-to-face structured educational program sessions and 5 diagnostic interviews have been performed.
Participants A sample of 42 adults (14 males, 28 females, mean age 54 years from 29 to 80 years) meeting the criteria for chronic insomnia according ICSD-3 was recruited from outpatient care of Department of sleep medicine of University Hospital №3 of I.M. Sechenov First Moscow State Medical University. All participants were informed about the nature, purpose, risks, and discomforts that could arise from their participation, and about their right to withdraw at any time. Subjects documented their willingness to participate by signing the informed consent form, approved by local Ethic Committee.
Treatment methods. BBT-I program includes two weekly one hour individual sessions; Hypnotic (zopiclone) in a dose of 7,5 mg has to be taken 30 minutes before bedtime for two weeks
Measures Questionnaires. During the first visit patients underwent structured clinical interview and filled in self-report questionnaires: Beck Depression Inventory (BDI), State-trait anxiety inventory (STAI), Toronto Alexithymia Scale - short version (TAS-20) , Big Five Questionnaire (BFQ-2R), Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Dysfunctional beliefs about sleep scale (DBAS), Sleep hygiene index (SHI).
During the next 4 visits participants repeatedly underwent diagnostic tests included BDI, STAI, PSQI, ISI, DBAS, SHI.
Participants kept daily sleep diaries where they recorded bedtime and morning rise time, sleep onset latency (SOL), number of night awakenings and time of wakefulness after sleep onset before waking up (WASO) for the whole study period.
On the last visit participants completed questionnaire for assessment of effectiveness of treatment along with diagnostic routine. Patients were asked to rank the effectiveness of proposed methods of treatment (didactic presentation, stimulus control, sleep restriction, relaxing recording and zopiclone) in ascending order from 1 to 5 points (5 seems most effective).
Polysomnography. Participants underwent in-lab PSG (1 night without adaptation night) prior to the treatment in order to exclude other disorders producing subjective sleep complaints (sleep apnea, periodic limb movements disorder). Standard polysomnography montage including 6 monopolar electroencephalography (EEG) channels; 1 submental electromyogram (EMG) channel; 2 electrooculogram (EOG) channels; 2 EMG channels of the right and left tibialis anterior muscles; 1 electrocardiogram channel; oronasal airflow pressure; thoracic and abdominal efforts; respiratory sound; oxygen saturation; body position with videomonitoring was performed. The objective sleep measures included total sleep time (TST), sleep-onset latency, wake time after sleep onset (WASO), number of awakenings, sleep efficiency (the ratio of TST to time spent in bed multiplied on 100%, SE), percentage of sleep stages. PSG data were analysed according the 2007 American Academy of Sleep Medicine criteria including its revision in 2012.
