HELIOS-BD
Lithium's mechanism in bipolar disorder:
Investigating the light hypersensitivity hypothesis
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VISION
Investigating Lithium and Light in Bipolar Disorder
Lithium has been in use for 70 years and is the most effective treatment for bipolar disorder. It has many actions but the precise mechanism of action in bipolar disorder is uncertain. Recent evidence suggests that lithium may work by stabilizing aberrant circadian rhythms of mood, cognition and rest/activity, possibly via an action at the level of the retina.
AIMS
We will test whether people with bipolar disorder are hypersensitive to evening light stimuli and whether Lithium may act to counter this.
CIRCADIAN RHYTHM
Individuals with bipolar disorder who are hypersensitive to the destabilizing effects of excess light in the evening may respond to lithium because it acts on the retina to make light-induced circadian disruption less likely.
This is a plausible and exciting hypothesis that, if true, could herald a new era of chronotherapeutic approaches.
LIGHT SENSITIVITY
Our primary hypothesis is that lithium is effective in bipolar disorder because it reduces hypersensitivity to evening light, making individuals less vulnerable to light-induced circadian disruption. If correct, this discovery will back-translate into more precise sub-phenotyping of early-stage bipolar disorder and new and more targeted chronotherapy approaches.
WORKSTREAM 2
Melatonin Supression and Lithium
Hypothesis: The administration of lithium to people with no history of mental illness reduces the magnitude of non-visual responses to light at night stimuli, assessed by the light-induced suppression of melatonin
Workstream 2 In Numbers
45
PARTICIPANTS
400mg
LITHIUM
600 LUX
MELANOPIC EDI
5
DAYS
WORKSTREAM 3
Bipolar Disorder, Melatonin Supression and Lithium
Hypothesis: People with bipolar disorder (relative to controls) exhibit greater non-visual responses to light at night stimuli (assessed by the light-induced suppression of melatonin) and these responses are attenuated for those on lithium therapy.
WORKSTREAM 4
Retinal Sensitivity in People with Bipolar Disorder