Early Morning Light Exposure Benefits Seasonal Affective Disorder Patients

WESTPORT, CT (Reuters Health) Jan 24 - Patients with seasonal affective disorder may need to wake up earlier to receive the greatest benefit from bright light therapy, investigators report January issue of the Archives of General Psychiatry.

To better understand the effects of light therapy on seasonal affective disorder, Dr. Michael Terman of the Columbia University College of Physicians & Surgeons in New York City and associates measured plasma melatonin in 42 patients. Measurements were performed in the evening or night while the patients were depressed, and in the morning or the evening after 10 to 14 days of light therapy.

While total overnight melatonin production did not differ according to the timing of light therapy, the time-curve of melatonin production did. The time curve was advanced up to 2.65 hours after morning light exposure, and was delayed up to 2.80 hours after evening light exposure.

According to results verified by the Structured Interview Guide for the Hamilton Depression Rating Scale-Seasonal Affective Disorder Version, improvement in symptoms was positively correlated with the size of phase advance.

According to Dr. Terman's group, the maximum advantage is achieved when light therapy of 10,000 lux for 30 minutes is scheduled approximately 8.5 hours after the baseline melatonin onset. Sleep midpoint, compared with sleep onset and offset, correlated best with melatonin onset, the investigators found. Therefore, they estimate that the optimum timing of light therapy would be 2.5 to 3.5 hours after the sleep midpoint.

The investigators clarify their recommendation, noting that it applies to "stable sleepers with 6 to 9 hours duration, onset between 10:00 PM and 1:00 AM and waking between 5:30 AM and 9:00 AM." In a university statement, Dr. Terman explained that "short sleepers will use the lights around the time of normal waking, while longer sleepers will need to wake up earlier."

Arch Gen Psychiatry 2001;58:69-75.
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... Ok, have I got this straight now??

Depending on when I go to bed, how long it takes me to get to sleep, then how long I sleep FOR, I might need to get up earlier to sit in the glow of my SADlite.

I take my doxepin (for alpha-delta sleep disorder related to fibromyalgia) at least one hour before bedtime to prevent frequent waking during the night. I must avoid taking Ibuprofen within 4 hrs of bedtime, as it has been shown to interfere with sleep. Unfortunately, so does my pain. Okay, I must take my levothyroxin on an empty stomach in the morning, one hr away from any food. According to the lowcarb experts, I'm supposed to eat a protein-containing breakfast within 2 hrs of rising.

I NEED A SECRETARY.

Doreen

[Edited by doreen T on 28-01-01 at 17:29]