Light Therapy uses exposure to bright light that can restore the balance between melatonin and serotonin through optic nerve stimulation, regularizing circadian sleep-wake rhythms, improving mood, appetite, and sleep quality.
What does Light Therapy consist of?
In humans, almost all physiological and behavioral functions have a rhythmic pattern. The length of cycles varies for different functions: from very short (ultradian rhythms), to daily (circadian rhythms), to rhythms with longer cycles (weekly, monthly, seasonal, or even longer).
Mood disorders, and in particular Seasonal Affective Disorder, appear to be related to alterations in circadian rhythms (Monteleone et al, Progress in Neuro-Psychopharmavology & Biological Psychiatry, August 2010).
A meta-analysis of 20 controlled studies shows that bright light treatment is effective in mood disorders, seasonal and non-seasonal in nature, with effects equivalent to those of most antidepressant drugs (Golden et al, The American Journal of Psychiatry, April 2005).
Light, through the optic nerve, can rebalance the balance between melatonin and serotonin, regularizing circadian sleep-wake rhythms, improving mood, appetite and sleep quality.
The eyes are the outermost part of the brain: it is important that they are stimulated by a particular light frequency.
Our body, and in particular the nervous and endocrine systems, receive, through light, valuable stimuli that regulate their proper functioning. Light stimuli reach certain regions such as the hypothalamus, which regulates the production of serotonin and cortisol, and the epiphysis, which regulates the production of melatonin. In this way, the neuro-endocrine system maintains the cyclicity that makes us feel good.
If this cyclicity is lost, disturbances result that can cause suffering and poorer quality of life. These disorders if properly assessed and recognized can be treated and even prevented, simply through light therapy.
Indications for the use of Light Therapy
The following indications for Light Therapy are derived from scientific studies, published in the literature, which have demonstrated its therapeutic efficacy in the following disorders:
Seasonal Affective Disorder (SAD);
Augmentation or acceleration in Pharmacological Therapy of Depression;
Depression during pregnancy;
Bulimia and Night Binge Syndrome;
Sleep and circadian rhythm disorders;
Adult ADHD associated with SAD;
Dementia and altered sleep-wake rhythm;
Obsessive-Compulsive Disorder (OCD);
Non-hemicranial headache and cluster headache;
Chronic Fatigue Syndrome;
Altered sleep-wake rhythm from work with night-day shifts;
Method of administration
It is necessary to sit about 50-70 cm from the light source, with your eyes open. Although there is no risk in looking directly at the light source, this is not essential for the effectiveness of the treatment. During the exposure, normal office work activities, reading or watching TV are possible. Treatment occurs on a daily basis and its duration varies according to the type of disorder and individual response, from 2 days to 2 months, even though on average, 2 to 4 weeks is sufficient. The indicated times of day for treatment, the duration of each individual exposure, the type of lamp, and the intensity of the light emerge from the individual clinical evaluation, which can make use not only of specific diagnostic tests but also of an accurate assessment of sleep quality and sleep-wake rhythm using actigraphy.
Contraindications and side effects
Light Therapy may present some minor contraindications and side effects, albeit to a lesser degree than pharmacological therapy. Therefore, it is worthwhile to evaluate along with the clinician the possible presence of contraindications and the occurrence of undesirable side effects after the first exposures.
Effectiveness of light therapy
The therapeutic effects of Light Therapy are widely documented scientifically by many studies in the world literature and can be surprising. The effects have not only been measured in terms of subjective improvement in mood, but also by measuring biological parameters such as levels of cortisol, melatonin, and certain functions of the serotonergic system.
Like most natural treatments, light therapy also requires commitment and motivation from the person involved. Thus, the patient is advised to adhere to the treatment protocol and exposure times and to modify certain lifestyle behaviors that could affect the results such as improving sleep hygiene, adhering to mealtimes, physical activity, and rest times.
Light Therapy is a treatment that can also be combined with traditional pharmacological therapy or even with alternative therapeutic strategies such as vitamin supplements, melatonin, magnesium, or ademethionine. For each individual case, the best treatment will be evaluated according to the patient's needs and related clinical conditions.