HELIOS BD 2

  • Research type

    Research Study

  • Full title

    Investigating the acute effect of lithium on visual and non-visual responses to light in healthy individuals.

  • IRAS ID

    333056

  • Contact name

    Nayantara Santhi

  • Contact email

    Nayantara.santhi@northumbria.ac.uk

  • Sponsor organisation

    University of Northumbria at Newcastle

  • Duration of Study in the UK

    3 years, 7 months, 30 days

  • Research summary

    This work package forms part of a broader study that aims to examine if people with bipolar disorder (BD) have an increased sensitivity to light and whether lithium might act to reduce this light sensitivity. Lithium has been used in the treatment of bipolar disorder for the past 70 years, but there is limited understanding of why it is more efficacious in treating some patients. People with BD often have disrupted circadian rhythms, which refers to the misalignment of the timing of sleep and wake with the standard 24-hour light-dark cycle. Circadian rhythms are largely influenced by light, and research suggests that people with bipolar disorder may have a heightened sensitivity to light, leading to disrupted circadian rhythms. The primary objective of the current study is to examine the mechanistic action of lithium in healthy participants and to assess if lithium will alter the magnitude of non-visual responses to light in healthy participants. Participation in the study is estimated to last for 26 days and we expect to recruit 45 participants over 4 years. During the first arm of the experiment, participants will not be taking any lithium and will be asked to come in for a 2-night stay at the sleep laboratory (baseline night followed by experimental light exposure night).This segment will be repeated with participants consuming lithium during the second arm of the study. A wider set of factors connected with mood, alertness, and performance will be assessed combined with other physiological measurements. This research will enhance understanding of the mechanistic action of lithium in healthy participants, and further our understanding of the combined effects of light and lithium in a healthy cohort. These findings will provide an understanding on how interventions can be better tailored for bipolar patients in the future.

  • REC name

    East of Scotland Research Ethics Service REC 1

  • REC reference

    25/ES/0069

  • Date of REC Opinion

    30 Sep 2025

  • REC opinion

    Further Information Favourable Opinion