Our brains and bodies are intricately linked to natural cycles of sunlight and darkness, known as circadian rhythms. Emerging research suggests that disruptions in these rhythms can significantly impact symptoms of ADHD, mood regulation, and cognitive functioning.

Circadian rhythms govern our internal biological clocks, regulating sleep-wake cycles, hormone production, mood, and cognitive processes. Sunlight exposure plays a pivotal role in synchronising these rhythms by regulating melatonin and serotonin production—two key hormones involved in mood and cognition (Roenneberg & Merrow, 2016).

Recent studies have identified a strong link between ADHD symptoms and circadian rhythm disturbances. Children and adults with ADHD frequently exhibit delayed sleep onset, fragmented sleep, and difficulties waking, suggesting dysregulated internal clocks (Coogan & McGowan, 2017). Such disruptions can exacerbate symptoms of inattention, hyperactivity, impulsivity, and emotional instability, further impairing cognitive performance and daily functioning.

Regular sunlight exposure, particularly in the morning, significantly improves circadian alignment and can mitigate ADHD symptoms. Natural sunlight exposure boosts alertness and concentration by stimulating cortisol production, while evening darkness enhances melatonin production, facilitating restful sleep (Wirz-Justice & Bromundt, 2020).

A study found that increased daylight exposure improved cognitive performance and reduced hyperactivity symptoms in children with ADHD, highlighting the importance of sunlight for optimal brain function (Figueiro & Rea, 2010).

Additionally, exposure to sunset light—characterised by warmer colours and reduced intensity—helps signal to the body that it is time to wind down, thus further promoting natural melatonin production and facilitating better sleep quality. This may also be protective against blue-light exposure from screens and devices in the evening. 

Practical Recommendations for Improving Circadian Health

• Morning sunlight exposure: Spend at least 10-20 minutes outdoors within 30 minutes after waking.

• Evening sunset exposure: Brief exposure to natural sunset light can help signal the body to begin preparing for sleep.

• Evening darkness: Limit bright artificial light exposure in the evening and utilise dim, warm-coloured lighting.

• Consistent sleep schedule: Consistent bedtimes is as or more important than the quantity of sleep. Maintain regular sleep-wake timings to strengthen circadian alignment.

Optimising sunlight exposure and maintaining healthy circadian rhythms are powerful yet simple strategies for improving ADHD symptoms, mood regulation, and cognitive performance. Integrating these practices with neurofeedback provides comprehensive support for neurological health and well-being. 

References

Roenneberg, T., & Merrow, M. (2016). The circadian clock and human health. Current Biology, 26(10), R432-R443.

Coogan, A. N., & McGowan, N. M. (2017). A systematic review of circadian function, chronotype and chronotherapy in attention deficit hyperactivity disorder. ADHD Attention Deficit and Hyperactivity Disorders, 9(3), 129-147.

Wirz-Justice, A., & Bromundt, V. (2020). Light therapy for circadian rhythm disorders. Dialogues in Clinical Neuroscience, 22(2), 149-161.

Figueiro, M. G., & Rea, M. S. (2010). Lack of short-wavelength light during the school day delays dim light melatonin onset (DLMO) in middle school students. Neuro Endocrinology Letters, 31(1), 92-96.