The two main external therapeutic methods used to advance the patient s sleep phase are bright light therapy and chronotherapy. When combined, these therapies are known to produce significant results. Back to Top Bright Light Therapy Early morning exposure to bright light tends to advance sleep onset at night and, ostensibly, to lead to an early wake time. Delayed sleep phase syndrome patients are, therefore, consistently exposed to bright light early in the morning. Because it can be difficult to get bright sunlight exposure early in the morning, especially in winter, artificial light is often used.
Patients often receive bright light therapy at home, with the use of a light box.
The patient sits in front of the light at a specified distance for approximately 30 minutes to one hour after waking in the morning. The dosage and timing of the light varies among patients. For instance, light given at 8 a.m. may have no effect on a certain patient, but exposing this patient to light at 7 a.m. may advance sleep onset by one to three hours. Furthermore, one hour of bright light exposure may actually cause insomnia for a patient with DSPS, while only 15 minutes may satisfactorily advance sleep onset. Generally, the earlier in the day that bright light therapy can be administered, the better.