Light therapy is a treatment for certain types of depression and other conditions. It requires the user to spend time near a light therapy box that gives off bright artificial light like natural outdoor light. This isn’t your typical house lamp.
It’s also known as phototherapy or bright light therapy (BLT).
Depression and light therapy
Light therapy is best known as a treatment for seasonal affective disorder (SAD), also known as major depressive disorder (MDD) with seasonal pattern.
It’s also used for treating types of depression that aren’t tied to the seasons, and other mental health conditions such as bipolar disorder.
SAD
SAD is a type of major depressive disorder. It’s typically triggered by seasonal changes, commonly during fall and winter when there are fewer hours of sunlight in the day.
Some people find the use of a light therapy box provides relief. Others find light therapy more effective when combined with additional treatments, such as psychotherapy or antidepressant medications.
Bipolar disorder
People with bipolar disorder may experience depressive episodes. According to 2018 research, light therapy can be a safe and effective add-on treatment for bipolar disorder depression.
The Mayo Clinic warns that, for some people with bipolar disorder, light therapy may trigger manic and mixed states. If you have bipolar disorder, be sure to talk with your doctor before trying light therapy.
How does light therapy work?
Lack of exposure to sunlight is thought to be linked to mood changes and seasonal depression. Light therapy is meant to compensate for that lack with a light therapy box. Light therapy boxes emit a bright light that mimics sunlight.
According to research, light therapy may help by either correcting your circadian rhythm or increasing serotonin.
A study in 2015 also suggested that light therapy may affect brain chemicals, such as serotonin, linked to sleep and mood.
For SAD, treatments usually take place from early fall to early spring. A typical session lasts 15 to 30 minutes, but length varies based on:
- How long you’ve been having the treatments
- The strength of the light therapy box
- How well you handle the treatment
It’s recommended to use the light therapy box within an hour of waking up in the morning.
Other conditions light therapy is used for
Bright light therapy can be used for conditions other than depression, including:
- Sleep disorders, such as insomnia
- Jet lag
- Dementia