RAISR4D Suicide

The influence of light on suicidality: A narrative review

23/05/2026

AI Summary

Light modulates brain circuits governing sleep and mood, suggesting a mechanistic link between light exposure and suicidality.
Epidemiological evidence ties suicide rates to season, time of day and sunlight exposure, and supports light-based treatment and prevention strategies.
A serotonin-centred neurochemical model is proposed, implying that understanding light-serotonin interactions could improve risk identification and novel prevention measures.

Chronobiol Int. 2026 May 22:1-9. doi: 10.1080/07420528.2026.2678278. Online ahead of print.

ABSTRACT

Suicide is a complex and deeply troubling phenomenon that occurs across all cultures and societies, representing a significant international public health challenge. Recent research has revealed a wide spectrum of ways light influences our brain circuits, with effects ranging from sleep-wake rhythm to mood regulation. Furthermore, a growing body of evidence highlights that light exposure is vital for both our physical and psychological well-being. In this paper, we hypothesize that light has an influence on suicidality. We examine evidence from several key areas: (1) currently available light-based treatments and suicide prevention measures; (2) the relationship between suicide rates and seasons; (3) the relationship between suicide rates and the time of day; and (4) the relationship between suicide rates and sunlight exposure. Based on the findings from studies exploring these topics, we propose a neurochemical model involving serotonin as a possible mediator of the relationship between light and suicide. A deeper understanding of the link between light and suicide could lead to a better identification of individuals at risk and potentially to the development of new, light-related suicide prevention measures.

PMID:42175620 | DOI:10.1080/07420528.2026.2678278

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