Kohei Nishikawa1,2, Kenichi Kuriyama3,4, Takuya Yoshiike5, Atsushi Yoshimura1, Masako Okawa6, Hiroshi Kadotani7, Naoto Yamada1,8. 1. Department of Psychiatry, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, 520-2192, Japan. 2. Japan CBT Center, CG building F4, 3-12 Chuo-cho, Hikone, Shiga, 522-0063, Japan. 3. Department of Psychiatry, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, 520-2192, Japan. kenichik@ncnp.go.jp. 4. Department of Sleep-Wake Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi, Tokyo, Kodaira, 187-8553, Japan. kenichik@ncnp.go.jp. 5. Department of Sleep-Wake Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi, Tokyo, Kodaira, 187-8553, Japan. 6. Sleep Health Promotion Organization Institute of Neuropsychiatry, 4-45-16 Otsuka Bunkyo-ku, Tokyo, 112-0012, Japan. 7. Department of Sleep and Behavioral Sciences Center, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, 520-2192, Japan. 8. Kamibayashi Memorial Hospital, 89-1 Okuchoorikuchinishi, Ichinomiya, Aichi, 491-0201, Japan.
Abstract
BACKGROUND: Cognitive behavioral therapy for insomnia (CBT-I) is a first-line therapy for insomnia disorders. We assessed changes in discrepancies between subjective and objective sleep measures and correlations between discrepancy changes and clinical insomnia severity for CBT-I in patients with primary insomnia METHODS: Fifty-two outpatients (mean age, 60.3 years; 26 women) with primary insomnia were treated by individual CBT-I (50 min, maximum six sessions, once every 1-2 weeks). One week before and after CBT-I, patients recorded a sleep log and wore an actigraphy device. Subjective and objective time in bed (TIB), total sleep time (TST), sleep-onset latency (SOL), wake time after sleep onset (WASO), and sleep efficiency (SE) were evaluated by averaging 1-week records. Relative values of sleep discrepancy in TIB, TST, SOL, WASO, and SE were calculated for estimating effects of CBT-I. The therapeutic effects were also evaluated using psychological scales before and after CBT-I. RESULTS: Subjective and objective discrepancies in sleep measures decreased by 36, 25, and 37 min in TST, SOL, and WASO, respectively, and 7% in SE (all P < 0.001) after CBT-I. Seven patients transitioned from underestimating SE before CBT-I to overestimating SE after CBT-I. Although CBT-I improved relative values of discrepancy in WASO and SE, alongside ISI, the improvement in insomnia severity only correlated with SOL discrepancy. CONCLUSIONS: CBT-I may reduce the discrepancy between subjective and objective sleep measures in patients with primary insomnia. However, a greater therapeutic effect of CBT-I was observed in reducing the ISI, which was slightly influenced by improvements in sleep discrepancies.
BACKGROUND: Cognitive behavioral therapy for insomnia (CBT-I) is a first-line therapy for insomnia disorders. We assessed changes in discrepancies between subjective and objective sleep measures and correlations between discrepancy changes and clinical insomnia severity for CBT-I in patients with primary insomnia METHODS: Fifty-two outpatients (mean age, 60.3 years; 26 women) with primary insomnia were treated by individual CBT-I (50 min, maximum six sessions, once every 1-2 weeks). One week before and after CBT-I, patients recorded a sleep log and wore an actigraphy device. Subjective and objective time in bed (TIB), total sleep time (TST), sleep-onset latency (SOL), wake time after sleep onset (WASO), and sleep efficiency (SE) were evaluated by averaging 1-week records. Relative values of sleep discrepancy in TIB, TST, SOL, WASO, and SE were calculated for estimating effects of CBT-I. The therapeutic effects were also evaluated using psychological scales before and after CBT-I. RESULTS: Subjective and objective discrepancies in sleep measures decreased by 36, 25, and 37 min in TST, SOL, and WASO, respectively, and 7% in SE (all P < 0.001) after CBT-I. Seven patients transitioned from underestimating SE before CBT-I to overestimating SE after CBT-I. Although CBT-I improved relative values of discrepancy in WASO and SE, alongside ISI, the improvement in insomnia severity only correlated with SOL discrepancy. CONCLUSIONS: CBT-I may reduce the discrepancy between subjective and objective sleep measures in patients with primary insomnia. However, a greater therapeutic effect of CBT-I was observed in reducing the ISI, which was slightly influenced by improvements in sleep discrepancies.