Sleep disorders
1. All circadian sleep-wake rhythm disorders
Meaning: disorders linked to work on an irregular schedule, or jet lag.
In work with irregular breaks, light therapy can be used as soon as night shifts end, during the rest time for recovery, to restore the normal wake-sleep cycle more quickly. It has also been suggested that light therapy be used during such irregular work periods, with different timing for each work regimen.
When preparing for travel across time zones, the principle is to anticipate the situation the traveler will encounter at the end of the trip. Thus, when flying west, the treatment is applied in the evening and when traveling east, it is applied in the early morning.
2. Sleep disorders in the elderly
It has been observed that elderly individuals often go to bed early, advancing the circadian rhythm phase. The result is prolonged nighttime awakenings with associated complaints, and daytime fatigue. In this case, the light therapy should be applied in the evening, to delay spontaneous asleep.
3. Cyclothymic depression with seasonal variations
In these cases, phototherapy should be used in the morning but generally at lower doses (500 lux for 2 hours) than in seasonal affective disorder and all other indications.
