Will light therapy treat depression?

Q: What are your feelings on light therapy for depression? I started taking Zoloft 50 mg when I was around 32 years of age. I’m now 49. My doctor increased the dosage to 75 mg upon having a panic attack in the spring of 2010.

I have no other health problems other than starting perimenopause. I haven’t had a cycle for three months. I read your column daily and would appreciate any input that you have on this matter.

A: Light therapy is a means of treating some forms of depression including seasonal affective disorder (SAD), a condition that occurs at a specific time of the year. This form of therapy is believed to affect brain chemicals linked to a person’s mood. In addition to SAD, light therapy may help with sleep disorders, dementia, jet lag, and types of depression that do not occur during a specific season. A different form of light therapy that emits more ultraviolet light is used for psoriasis and some other skin conditions.

Side effects of light therapy may include headaches, eye strain, nausea and irritability in some individuals. Should side effects occur, they may dissipate on their own shortly after the therapy begins. Unwanted side effects may be controlled by sitting farther away from the light box, changing the time of day the therapy is administered, or reducing the treatment time. Remember that you may have a condition such as lupus that makes your skin sensitive to light, or you may be on a specific medication that will increase your sensitivity to light. Antibiotics, St. John’s wort and anti-inflammatories are known to cause a reaction in some individuals. For example and coming from an area where Lyme disease is common, the antibiotic doxycycline can cause photosensitivity, meaning that an individual on the drug should either stay out of the sun for the duration of the prescription or should wear long-sleeved shirt and pants when out of doors as a means of prevention.

Light therapy may trigger mania in some individuals who suffer from bipolar disorder. Were this to be your diagnosis, you should speak with your primary care physician or mental health provider to determine if light therapy is right for you and if any precautions should be taken. For example, your doctor may recommend exposure for 15 minutes at a time, gradually working up to longer periods. Depending on the intensity of the box, light therapy will range from 30 to 120 minutes daily. Most individuals prefer exposure during morning hours but your schedule may demand later timing. Lastly, the intensity of a light box is recorded in lux, a measure of the amount of light received at a specific distance from a light source. Boxes commonly produce somewhere between 2,500 and 20,000 lux. A 10,000 lux box usually requires 30 minute sessions, while one of lesser intensity such as the 2,500 box may require 120 minute or two hour sessions. The intensity of the box will determine how far you sit from it and the length of time you should use it. There is no need to sit idle while receiving therapy. You can read, sit in front of a computer, watch a television show and do other things while receiving the light therapy. Finally, and in answer to your question, it isn’t likely light therapy will cure your depression because this form of therapy is efficacious for Seasonal Affective Disorder, not depression, a condition that is treatable by a variety of other methods.

Lastly, your Zoloft is an antidepressant in a group of drugs known as SSRIs (selective serotonin reuptake inhibitors). It is also prescribed for panic and anxiety disorders, premenstrual dysphoric disorder, and post traumatic stress. Common side effects can include upset stomach, nausea, abdominal pain, constipation, dry mouth, insomnia and changes in appetite or weight. The initial dose is 50 mg taken orally, up to 200 mg. Your physician is on the money with your Zoloft, so why not ask him or her whether light therapy will work for you? You’ve got nothing to lose and a more pleasant day to gain whether the answer is yes or no.