Phototherapy: what is it, what is it for and how is it used

While it may seem like something very mystical, light can heal, or at least reduce, the symptomatology of certain medical problems and psychological disorders.

Phototherapy is a set of treatments in which light is used to help increase mood in psychiatric patients and also reduce inflammation and other skin problems. Below we will take a closer look at what this technique is, especially in the field of psychiatry.

    What is phototherapy?

    Phototherapy, also called light therapy or light therapy, is a therapeutic tool in which electromagnetic radiation is used, i.e. light, for the treatment of medical diseases and psychopathological disorders. The type of light applied can be visible, infrared or ultraviolet radiation.

    In the field of medicine, phototherapy is mainly used in the treatment of skin diseases, such as vitiligo or psoriasis. In the case of psychology and psychiatry, this has been shown to be useful in the treatment of mood disorders, especially seasonal affective disorder.

      That is to say?

      Basically, phototherapy involves exposing the patient to a device, such as a phototherapy light, or sunbathing, so that the light affects their skin and activates biochemical processes. The light from the phototherapy lamp is very similar to natural light.

      It is believed that phototherapy affects chemicals in the brain associated with mood and sleep. For this reason, it is used in the treatment of seasonal affective disorder, a mood disorder that occurs at a certain time of the year, especially associated with a lack of natural light. For this reason, most people who exhibit it manifest it in the fall or winter.

      What advantages does it have?

      In its use in psychopathology, not constituting a pharmacological treatment, phototherapy is associated with a treatment which involves few side effects. In the event that drugs, especially antidepressants, are already consumed or psychological therapy is used, the use of this technique can help to increase the effectiveness of these treatments, Allowing a lower dose of medication to be consumed.

      It is also used in pregnant or breastfeeding women who cannot take psychotropic drugs because, although not all, there is a risk that they will end up in the baby.

      What diseases and disorders is it used for?

      As we were already discussing, phototherapy it is used in particular for dermatological diseases and mood disordersHowever, there are many other conditions in which the technique has shown great effectiveness.

      Among the mental disorders for which it is used, we can find mood disorders such as:

      • Seasonal affective disorder

      • Depressions not associated with the season

      But in addition, they are used to treat disorders in which the person presents some kind of mismatch in your sleep cycle, Whether for professional reasons, long journeys (jet lag) or difficulty in reconciling sleep.

      • jet lag
      • Sleep disorders
      • Night work schedule
      • dementia

      When it comes to skin diseases, we find psoriasis. In phototherapy applied to this type of problem, ultraviolet light must be filtered as it can damage the eyes and skin.

      Possible side effects

      In the case of phototherapy applied to mood disorders, although it is a safe technique, it carries certain risks, Which are light and short-lived. Among these we can find:

      • Headache
      • dizziness
      • eye strain
      • irritability
      • Nervousness (associated with bipolar disorder)
      • Mania and euphoria
      • hyperactivity

      Side effects can be controlled by reducing the duration of treatment, moving away from the light, taking breaks for long sessions, or changing the time of day it is used. They can also appear immediately after starting treatment, but they may decrease as it progresses.


      Although the use of phototherapy may seem trivial, it should be remembered that it is a medical treatment, and therefore care must be taken when using it, in addition to relying on the criteria professional doctor, psychologist or psychiatrist who recommended it.

      Some of the considerations to consider before starting treatment with the light are the find out if you have a skin condition, which makes it particularly sensitive to light and that it can get worse if this technique is applied, as would be the case with systemic lupus erythematosus. The case of eye disease, which returns to the eyes most vulnerable to minor injuries, deserves special attention.

      If you are taking medication, you should ask the prescribing professional and look at the package leaflet to see if this increases sensitivity to the sun. Some of the drugs that can have this side effect are certain antibiotics, anti-inflammatory drugs, or herbal medicines, as is the case with St. John’s Wort.

      In people with bipolar disorder, it is especially important to watch them apply light therapy, as one of its side effects is triggering mania.

      ultraviolet light

      Phototherapy lamps should be designed to filter ultraviolet light, Which is harmful to the skin and eyes. While in most cases, and especially for use with the skin, they are already designed to filter the skin, they are not always successful at all.

      It is for this reason that special care should be taken with this type of device because, as we said, although they may appear very harmless, in the absence of good control there is a risk of problems. on the skin, such as blemishes, melanomas and burns. Appointment with a dermatologist before and during the application of the techniqueEven if you are using it for a mood disorder, it is still recommended.

      When is the best time to start?

      Light therapy prescribed for people with seasonal affective disorder usually begins in early fall, when the skies begin to cloud over many parts of the world and the rains begin. Due to the lack of sunlight, cloudiness appears. that’s why phototherapy is applied to compensate for the lack of light stimulation in the most sensitive people. Usually, the treatment continues until spring, when there is already more outside light and this is enough to maintain a good mood and higher energy levels.

      During light therapy, the person sits or works near a specialized lamp. To be effective, light must enter the eyes indirectly, in addition to affecting the skin. One of the biological bases of depression is related to the lack of light and alterations in sleep cycles, for this reason, entering through the eye, this light helps regulate sleep cycles, as it serves the brain to regulates and, when there is light, know that it is not time to sleep, that it is daylight.

      But beware! do not look at the light directly, As they can damage the eyes. The recommendations of the healthcare professional who recommended it should be followed, in addition to consulting the manufacturer’s instructions.

      It is not a therapy that automatically induces improvement. It takes time and persistence, like any other treatment. Do not expect that with just one session, we will have a significant improvement in our mood.

      One of the recommendations is to have this light on near a place where we often live in the house., Like the office, living room or any other place where we spend a lot of time.

      How should it be applied to make it effective?

      There are three key elements in making sure this therapy is effective.

      1. Intensity

      The intensity of light is recorded in lux (“light” in Latin), which is the measure of the amount of light received. For seasonal affective disorder, her usual recommendation is to use a light intensity of 10,000 lux, Placed at a distance of half a meter from the face.

      2. Duration

      With an intensity of 10,000 lux, phototherapy generally requires 20 to 30 minute sessions. In the case where the light intensity is lower, we put 2500 lux, longer sessions may be necessary.

      3. Time of day

      For most people, light therapy is most effective when done early in the morning, freshly woken up. Although some people find it more helpful to have the sessions at other times of the day. To do this, you need to consult your doctor in order to establish a schedule that best suits your particular case.

      Other types of lamps

      Other similar products are these.

      1. Infrared radiation light

      It is used as heat therapy, using the infrared camera. It is not visible light, it simply gives off heat and is not applied for mood disorders, but for skin problems.

      2. Laser

      It is a special artificial light, which consists in amplifying the light by a process of stimulated emission of radiation. It is considered a technique of phototherapy, although it is not applied in the field of psychological disorders and its application in skin diseases is very specific.

      Light and a chemical compound are needed, which can be liquid, solid or gas. The light stimulates the chemical, increasing its energy. When the energy affects the compound, it is when the laser itself appears, seeing a single color and sometimes with the ability to cut tissue.

      There are two types of lasers for medical use: The soft and the hard.

      The soft, with a radiation of 10 to 20 mW (millivatios), is used to sweep the skin and has analgesic, anti-inflammatory and tissue regeneration effects.

      The hard disk has a radiation greater than 10 W (watts), being its use quite powerful. This can cause cell vaporization, photo coagulation, or even cell explosions. It can be used to cut tissue (laser scalpel), photocoagulate in case of retinal detachment or remove tattoos and blemishes. It can have pathogenic effectsIt is contraindicated in pregnant women and people with cancer.

      About solar beds

      When we talk about phototherapy lamps, we can think of them as looking like sun beds, that is, those that used to darken. Since the benefits of sunlight are already known in popular culture, many people may fall into the mistake of thinking that solar beds are a good alternative to solar lights., In addition to offering us a brunette for the summer. This is not the case.

      They have not been shown to help relieve symptoms of Seasonal Affective Disorder, plus they release ultraviolet light which, as we have seen previously, they can damage the skin and increase the risk of skin cancer.

      Bibliographical references:

      • Golden, RN, Gaynes, BN, Ekstrom, BD (2015). Effectiveness of phototherapy in mood disorders: review and meta-analysis of the evidence. Am J Psychiatry.

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