Bright light therapy

What is bright light therapy for bipolar disorder?

Bright light therapy, also called phototherapy, involves the use of a bright artificial light to improve depressive mood. It has long been used in psychiatric practice, usually for the treatment of seasonal affective disorder. The mechanism by which bright light therapy regulates mood is unclear. It has been suggested to have modulating effects on serotonin and melatonin and on the synchronisation of circadian rhythms, which is why it is often accompanied by sleep deprivation. This topic assesses the use of bright light therapy for depressive symptoms of bipolar disorder.

What is the evidence for bright light therapy?

Moderate to high quality evidence finds a medium-sized improvement in depression symptoms with bright light therapy compared to placebo. There was no increased risk of shifting to a manic state with bright light therapy.

Moderate quality evidence finds greater improvements in depression symptoms in studies using <10 hours compared to >10 hours of bright light therapy, in studies using morning plus night exposure compared to morning exposure only, and in studies with adjunctive sleep deprivation and/or lithium. There were no differences in studies with or without other psychotropic medications, in studies using colour temperature < vs. >4500k, in studies using light intensity < vs. >5000lux, or in studies using white or green light thera

November 2021

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Last updated at: 1:59 pm, 15th February 2022
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Green - Topic summary is available.
Orange - Topic summary is being compiled.
Red - Topic summary has no current systematic review available.