AT THE ISTITUTO DI NEUROSCIENZE DEPRESSION IS TREATED WITH THE LIGHT THERAPY
In humans almost all physiological and behavioural functions occur on a rhythmic basis. There are cycles of varied lengths in biological activities, from very short (ultradian) rhythms to rhythms with a period of approximately one day (circadian) and rhythms with longer cycles, of a week, a month, a season, or even longer.
These rhythms are generated by endogenous biological clocks, i.e. time-keeping structures, rather than being passive reactions to external fluctuations. Mood disorders such as seasonal affective disorder and major depression have been linked to circadian rhythms alterations.
According to verified studies, the exposure to bright light is an efficient treatment against seasonal and non-seasonal mood disorders, with similar effects to most anti-depressive drugs [American Journal of Psychiatry, April 2005].
Through the optic nerve, light re-establishes the correct melatonin-serotonin balance and regulates the circadian sleep-waking cycle, thus improving mood, appetite and the quality of sleep.
The eyes are the brain’s most external part: it is important that they are stimulated with a particular frequency of light.
Through light, our body, and in particular the nervous and endocrine systems, receive precious stimuli that regulate their correct functioning. Light stimuli reach particular regions of the brain, such as the hypothalamus, that regulates the production of serotonin and cortisol, and the pineal gland, which regulates the production of melatonin. In this way the neuroendocrine system operates cyclically thus guaranteeing our well-being.
The interruption of this cycle generates disorders that cause distress and decline in the quality of life. If adequately assessed, similar disorders can be treated, if not avoided at all, thanks to light therapy.
INDICATIONS FOR THE USE OF LIGHT THERAPY
Scientific studies, published in literature, have demonstrated the therapeutic efficacy of light therapy in the following cases:
- Seasonal affective disorder (SAD)
- Non-seasonal depression
- Augmentation or acceleration in pharmacological therapies against depression
- Pregnancy depression
- Night Eating Syndrome
- Sleep and circadian rhythm disorders
- Jet lag
- Alteration in the sleep-waking cycle due to shift work alternating day and night shifts
- Children’s ADHD
- Adult’s ADHD associated to SAD
- Premenstrual syndrome
- Dementia and alteration of the sleep-waking cycle
- Obsessive-compulsive disorders
- Non-migrainous and histaminic headache
- Chronic Fatigue Syndrome
Patients sit down about 50-70 cm from the source of light, with open eyes. Although looking directly the light is not dangerous, this is not essential for the treatment to be effective. During exposure to light patients can dedicate to normal office occupations, read or watch TV. The treatment consists in daily sessions; its duration can vary from 2 days to 2 months and depends on the kind of disorder and on individual response, although the average treatment lasts from 2 to 4 weeks. Specific diagnostic tests and an accurate assessment of the quality of sleep and of the sleep-waking cycle by means of actigraphy help to determine the hour of day suitable for the treatment, the duration of any single session, the kind and the intensity of light.
CONTRA-INDICATIONS AND SIDE-EFFECTS
Despite having less contra-indications than any pharmacological therapy, light therapy presents nevertheless some minor side-effects. We therefore recommend that the emergence of any contra-indications or side-effects be assessed after the first few sessions together with an expert.
Many scientific studies in world literature report light-therapy therapeutic results, which may even be surprising. Not only has light therapy effectiveness been measured in term of subjective mood improvement but also through biological parameters, such as cortisol and melatonin levels and in relation to particular functions of the serotoninergic system.
Like most of natural treatments, light-therapy requires commitment and motivation from the part of the subjects. Patients are therefore advised that they respect the treatment protocol and the exposure times and that they modify some of their habits that could influence the results of the treatment by improving sleep hygiene and respecting meal, physical activity and rest times. Light therapy can be associated to a traditional pharmacological therapy or to alternative treatments with vitamin supplements, melatonin, magnesium or ademethionin. Any single case will be assessed taking into consideration the patient’s needs and clinical conditions.