Treatment via Light Therapy
Light therapy alternately known as photo therapy is exposure to certain specific wave lengths of light. This is effective in curing sleep disorders, seasonal affective disorder and non seasonal affective disorder.
SAD during winters
SAD symptoms are the maximum during January and February, the peak months of winter and they start fading out by March and April.
Evaluation of SAD takes a minimum of two years. The doctor has to first ascertain that the patient is really suffering from SAD and not any other kind of depression. Once other possibilities are ruled out the best possible cure (preferred by almost 80% of the people) for SAD is light therapy.
Treatment via light therapy
Light box contains a set of fluorescent lights installed in a box with a diffusing screen. The cost of this unit should not be more than $300. It looks like a mini sized x-ray machine. Cost of the equipment is not covered by insurance for the results of its efficacy have not been proved on solid ground. The light box gives out bright light while blocking the ultra violet rays.
The person has to sit in front of these lights with open eyes. Though looking directly into the light is not recommended the person can keep himself occupied by reading a book, having his meals or indulging in any other activity.
Duration for light therapy
Duration for the treatment depends upon each individual case and the doctor’s discretion. The prescribed duration can be anywhere between 15 minutes to 3 hours a day while on an average many cases require a light exposure lasting 30 minutes a day. If the doctor feels that treatment for longer durations are required he would increase the prescribed time gradually and not at one go. Duration of the light therapy also depends on the brightness of the light. Exposure to 10000 lux requires sittings for a lesser duration when compared to lights of 2500 lux.
Working of light therapy
A few probable theories that substantiate the efficacy of light therapy are explained below.
One is that melatonin is responsible for the sleep wake cycle. The production of melatonin is also related to mood and violence. As has been mentioned since melatonin regulates the sleep pattern it is released when the lights are low to induce sleep. Bright light reduces the production of melatonin, there by reducing depression as melatonin and mood disorders are linked.
Sunlight affects the circadian or biological clock that affects the mood and sleep cycles. Lack of sunlight thus brings about disturbance of the mood and sleep cycle thereby leading to depression.
Sunlight increases the production of serotonin that promotes the feel good factor. Absence of sunlight therefore causes depression.
The efficacy of the light treatment is not based on rigorous study. Bright light and dawn simulation work well for relieving SAD while only bright light is used for non seasonal depression. The exact effectiveness of the light therapy in relation to placebo effect will be proved with further study.