How Effective Is Light Therapy for Seasonal Affective Disorder?

Light therapy for seasonal affective disorder symptoms is said to be an effective way to manage this condition. Some studies suggest that light therapy may also be effective for relieving the symptoms of non-seasonal depressive disorders, such as major depression and bipolar disorders. Light therapy for seasonal affective disorder is believed to be safe, with few side effects and little risk. Persons diagnosed with co-morbid bipolar disorder may need to exercise caution when using light therapy for seasonal affective disorder, since the lights used can sometimes trigger periods of mania or hypomania in persons with bipolar disorder. In studies, some patients have experienced a worsening of depression symptoms while using light therapy, so medical supervision is usually recommended.

Seasonal affective disorder (SAD), is a type of depressive disorder that generally causes depressed mood during the winter months. Some patients experience symptoms of depression in the summer, rather than in the winter. Some patients experience depression symptoms during both summer and winter, with a general remittance of symptoms during the spring and fall. Others may experience a recurrence of symptoms during long periods of foul weather, when the sky is overcast, regardless of season.

Doctors do not yet fully understand what causes seasonal affective disorder. Many patients have, however, experienced partial or full relief of SAD symptoms using light therapy. While research into the efficacy of light therapy for seasonal affective disorder is not generally considered complete, studies suggest that light therapy may be as effective as oral antidepressants in relieving depression symptoms. Most physicians believe that light therapy carries far fewer side effects and risks than oral antidepressants.

Light therapy for seasonal affective disorder generally involves the use of a light box. The light boxes typically used for SAD treatment don’t produce UV rays, but instead produce visible spectra of light. These visible spectra aren’t considered harmful to the skin or eyes, though patients with eye or skin conditions may want to speak with a physician about possible complications due to light therapy. Headaches and eyestrain may be the most common side effects of light therapy in healthy patients.

This type of therapy is generally done in the morning. Patients are typically asked to sit in front of and, ideally, slightly below a light box for some period of time in the morning. The period of time necessary for one successful light therapy session may vary from 15 minutes to two hours, depending on the type of light box used and the severity of the patient’s symptoms.

Most patients are asked to sit in front of the light box for 30 minutes each morning until symptoms of depression abate. Maintenance sessions of 15 minutes per morning are usually recommended once relief of symptoms has been achieved. Light therapy generally begins in early autumn, and typically continues throughout the winter until late spring.