Sleep and circadian rhythms: expert guidance on insomnia, CBT-I, and menopause with Dr Ali Hare

Science Weekly's sleep episode features Ian Sample interviewing sleep specialist Dr Ali Hare about how light and daily routines shape our circadian rhythms, and when sleep becomes a problem. The conversation covers insomnia and menopause-related sleep disruption, cognitive behavioral therapy for insomnia (CBT-I) as the gold-standard treatment, the role of hormonal therapies for hot flashes, sleep paralysis, and how sleep relates to dementia risk. It also discusses the limits of over-the-counter sleep aids and wearables, and provides actionable tips—regular bedtimes, bright daytime light, mindful caffeine use, and consistent daytime activity—for improving sleep quality. The discussion highlights the glymphatic system and amyloid clearance, offering evidence-based guidance for better rest.

Introduction

Science Weekly welcomes listeners to a focused discussion on sleep health, circadian biology, and practical strategies to improve rest. Host Ian Sample guides a conversation with sleep specialist Dr Ali Hare, drawing on clinical experience at Guy's and Saint Thomas' Hospital and the British Sleep Society to unpack why so many people struggle to sleep and what can be done about it.

“Light is the most significant zeitgeber, the cue that tells us what time of day it is.” - Dr Ali Hare

The science of sleep: circadian rhythms and light

The episode emphasizes the central role of light as a driver of when we fall asleep and wake up, describing chronotypes as partly genetic preferences for early or late schedules. Hare explains that regular bed and wake times help maintain rhythm, while bright light exposure during the day can support a reliable sleep pattern even in the face of individual chronotypes. The discussion also covers the glymphatic system, which clears waste from the brain mainly during sleep, linking sleep duration and quality to long-term brain health and dementia risk.

“Light is the most significant zeitgeber, the cue that tells us what time of day it is.” - Dr Ali Hare

Insomnia and circadian rhythm disorders: insomnia, menopause

The podcast delves into common sleep problems, with insomnia and sleep apnea highlighted as frequent clinic presentations. Special attention is paid to menopause, where night‑time awakenings and hot flashes can disrupt sleep. Hare notes that CBT for insomnia (CBT-I) is highly effective for menopause‑associated insomnia, and hormonal treatments can help hot flashes. The British Menopause Society offers guidance on treating sleep problems during this life transition. The conversation also addresses how to handle awakenings at night, including pragmatic strategies to restore efficiency of sleep and daytime functioning.

“The gold standard treatment for insomnia remains cognitive behavioural therapy for insomnia.” - Dr Ali Hare

Sleep and dementia: connections and cautions about medications

The link between sleep and dementia is discussed, with evidence that reduced sleep opportunity and insomnia correlate with higher dementia risk. The glymphatic clearance of amyloid beta during sleep is proposed as one mechanism behind this association. Hare cautions against relying on sleeping pills as a dementia preventive strategy due to dependency risks and differences between pharmacologic sleep and natural sleep, while noting newer agents with fewer drawbacks. CBT-I remains the recommended first-line intervention for chronic insomnia.

“Reduced sleep opportunity and insomnia are linked to dementia.” - Dr Ali Hare

Technology, wearables, and practical sleep‑hygiene tips

Wearables and sleep trackers are discussed in the context of accuracy and user behavior. While devices have improved, over-interpretation of sleep scores can lead to orthosomnia, a fixation that worsens sleep. Hare encourages using technology to understand trends, not as a sole determinant of sleep quality. Practical tips include maintaining regular light exposure, minimizing caffeine later in the day, and engaging in regular daytime activity to support better sleep at night.

Conclusion and practical takeaways

The episode wraps with clear takeaways: regulate light exposure, keep a regular schedule, pursue CBT-I for chronic insomnia, consider menopause‑related treatments when appropriate, and use sleep tech judiciously. The overarching message is that good sleep is achievable with evidence-based approaches and daily lifestyle adjustments.