About this trial
The primary objective of the current study is to examine the acute effect of lithium on the visual and non-visual responses to light in a sample of healthy participants. Our experiments will investigate the effects of lithium on light sensitivity at the level of the retina as well as central visual and non-visual pathways.
Our primary hypothesis is that the administration of lithium to healthy volunteers will reduce the magnitude of a range of non-visual responses to light including melatonin suppression, alertness, performance, mood and electrophysiology in a manner that is dependent of the amount of lithium in the brain. To better understand the postulated effects of lithium on light sensitivity and to examine its relationship at the level of the retina, we will assess the visual and non-visual responses to light, as well as the distribution of lithium in the brain using a non-invasive imaging technique. In addition to that, we also aim to examine the impact of both lithium and light on a molecular level through whole blood transcriptome sequencing.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
Aged between 18 and 40 years old
Fluent in English (both spoken and written)
Sleep duration between 6.5 and 9 hours daily
Have a regular normal sleep schedule with bedtime (weekdays) between 21:30 and 01:00.
Disqualifiers
History of psychiatric or neurological disorders
First-degree family history of psychosis or severe mood disorder
Current or past suicidal ideation or self-harm
Current, chronic infections or diseases.
Trial design
Single group
Treatments tested in this trial
Lithium carbonate (Priadel)
DrugOral lithium carbonate 600 mg daily for 7 days prior to the second laboratory assessment (and for both days while in the laboratory)
Controlled light exposure
Other interventionParticipants undergo 90-minute dim light (\<1 lux) and light exposure (100-850 lux) conditions during laboratory assessments to evaluate visual and non-visual responses to light.
Treatment groups
Trial outcomes
Primary outcomes
Plasma melatonin change in response to light stimulation
Difference in plasma melatonin suppression following light exposure between the no-lithium and lithium conditions.
Brain lithium signal intensity measured by 7Li-MRI
Quantification of brain lithium signal intensity using 7Li magnetic resonance imaging following 9 days of lithium carbonate administration in healthy participants.
Secondary outcomes
Difference in colour vision post-light exposure between lithium and no-lithium conditions
To determine differences in the Cambridge Colour Test (CCT) for changes in colour vision between the lithium and placebo groups post light exposure
Waking EEG Measures
Hourly waking electroencephalography (EEG) data collected when the participant is awake in the lab will be compared between the lithium and no-lithium conditions. EEG data collected pre, post and during the 90-minute light exposure will be compared between the lithium and no-lithium conditions.
Pittsburgh Sleep Quality Index
Difference in Pittsburgh Sleep Quality Index total score between the lithium and no-lithium conditions in healthy participants. The global score on ranges from 0 to 21, where higher scores represent poorer sleep quality.
Munich Chronotype Questionnaire
Difference in Munich Chronotype Questionnaire(MCTQ) measures between the lithium and no-lithium conditions in healthy participants. Total score on the MCTQ ranges from 16 to 86, with 16 to 41 being the eveningness type, 42 to 58 being the intermediate type, and 59 to 86 being the morningness type.
Sponsors and contacts
Click on the lead sponsor to view all of their trials.
Northumbria University
Lead sponsor
Newcastle University
Collaborator
Northumberland, Tyne and Wear NHS Foundation Trust
Collaborator
This trial is not recruiting at the moment. You can still explore other options: