ABSTRACT

Background

Approximately 11–33% of Australian adults experience Insomnia Disorder, which is associated with higher rates of psychiatric comorbidities, and lower quality of life. Non-pharmacological interventions are the front-line treatments for insomnia. Despite the known impact of light on the sleep/wake cycle via the circadian system, it is not yet known whether seasonal variations in environmental light levels (i.e., daylength) influence treatment outcome. We aimed to determine whether seasonal differences in daylength influenced baseline symptoms of Insomnia Disorder or treatment outcome.

Participants

One hundred treatment-seeking individuals with Insomnia Disorder (age: 49.3 ± 14.4y, range: 18–82 years; 58 F) enrolled in a Randomized Control Trial in Australia over a 29-month period.

Methods

Clients completed a seven-session behavioral intervention for insomnia over a maximum of 12 weeks. Individuals completed questionnaires assessing insomnia symptoms, diurnal preference, depression and anxiety symptoms, and daily sleep diaries. Objective rest/activity patterns were monitored using wrist actigraphy for the duration of the treatment period.

Results

Baseline daylength, sunset and sunrise times, and change in daylength over treatment, were not related to baseline insomnia severity or mental health symptoms. However, longer daylength at baseline predicted greater improvements in insomnia symptoms and anxiety, but not depression, symptoms. These improvements were also associated with later sunset and/or earlier sunrise at baseline.

Conclusions

Our results show, greater treatment-related improvements in subjective sleep and mental health symptoms during spring and summer months. This suggests that daylength could have a role to play in the outcomes of a behavioral insomnia treatment. Future research is needed to provide recommendations.

中文翻译：

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在失眠行为干预期间，白天长度会影响睡眠和心理健康症状吗？

摘要

背景

大约 11-33% 的澳大利亚成年人患有失眠症，这与较高的精神疾病发生率和较低的生活质量有关。非药物干预是失眠的一线治疗方法。尽管已知光照通过昼夜节律系统对睡眠/觉醒周期产生影响，但尚不清楚环境光照水平（即日长）的季节性变化是否会影响治疗结果。我们旨在确定昼长的季节性差异是否会影响失眠症的基线症状或治疗结果。

参与者

一百名寻求治疗的失眠症患者（年龄：49.3 ± 14.4 岁，范围：18-82 岁；58 F）在澳大利亚参加了一项为期 29 个月的随机对照试验。

方法

客户在最长 12 周内完成了为期七次的失眠行为干预。个人完成了评估失眠症状、昼夜偏好、抑郁和焦虑症状以及每日睡眠日记的问卷调查。在治疗期间使用腕部活动图监测客观的休息/活动模式。

结果

基线日长、日落和日出时间以及治疗后的日长变化与基线失眠严重程度或心理健康症状无关。然而，基线时较长的日长预示着失眠症状和焦虑症状的改善更大，但抑郁症状没有改善。这些改进还与基线时的较晚日落和/或较早日出有关。

结论

我们的研究结果表明，在春季和夏季的几个月中，主观睡眠和心理健康症状与治疗相关的改善更大。这表明白天长度可能在行为失眠治疗的结果中发挥作用。未来的研究需要提供建议。