Research & Practical Evidence

Lighting treats bipolar patients at Valen Hospital in Norway

Written by Ane Eskildsen | May 26, 2023

Groundbreaking research findings have prompted the emergency department to introduce circadian lighting for bipolar patients. The lighting is customized for individual treatment, and initial experiences have been positive.

Since 2015, Tone Elise Gjøtterud Henriksen has been at the forefront of research in dark and light therapy for bipolar disorder. Her groundbreaking findings have been published in reputable journals such as Bipolar Disorders and Journal of Sleep Research, undergoing a rigorous peer-review process.

— According to Tone E. G. Henriksen, a senior physician at the emergency department of Valen Hospital in Norway, research has shown that blocking the blue wavelengths of light in the evening and at night can reduce manic symptoms in bipolar patients and improve their sleep.

The results confirm previous studies on dark therapy, but this is the first randomized, controlled study with blue-blocking. In the study, the blue light is blocked through special glasses provided to the patients. Following the study, the International Society for Bipolar Disorders (ISBD) has developed an international recommendation to incorporate light therapy as part of the treatment for bipolar patients.

Research put into practice

The effectiveness of light therapy for all types of depression is well-established, leading Valen Hospital to collaborate with lighting specialists from Chromaviso and Italian researcher Francesco Benedetti to develop a light therapy room in the psychiatric emergency department for the treatment of depressed patients. The integrated light therapy lamp can be customized for each patient in terms of colour temperature and intensity. It was implemented in March 2019.

— The light therapy room is highly effective and is used daily by the patients. We offer it as an alternative or supplement to medication for all depressed patients. Research has shown that light therapy alone can be just as effective as medication alone. However, when the two are combined, the effects are doubled, as explained by Tone E. G. Henriksen.

Despite the systematic collection of data from the emergency department at Valen Hospital not having commenced yet, Tone E. G. Henriksen has observed positive effects of the light. Additionally, the length of hospital stays has been positively influenced.

— We have observed a decrease in the length of hospital stays for patients using the light therapy room. Typically, these patients are admitted for 1-2 fewer days compared to the average stay of 7-8 days. Furthermore, patients are extremely satisfied with the light therapy and report feeling better overall. They appreciate the fact that their treatment includes more than just medication, she explains.

Furthermore, light therapy also aids patients with disrupted circadian rhythms, such as those who oversleep or stay awake too late.

Circadian lighting tailored to the phases of mania

In October 2019, Tone E. G. Henriksen made the decision to expand the implementation of the positive results by installing circadian lighting in a connected section with common areas, hallways, and patient rooms. This allows patients to be exposed to light/dark therapy around the clock, without the need to constantly put on and take off the blue-blocking glasses at specific times.

Bipolar patients are highly sensitive to light, and the alternation between light and darkness has a synchronizing effect on their circadian rhythm. This can act as a trigger for both manic and depressive episodes, directly impacting their mood and energy levels through the influence of neurotransmitters such as dopamine, serotonin, noradrenaline, and the hormone melatonin.

Therefore, Tone E. G. Henriksen and lighting expert Torben Skov Hansen from Chromaviso developed a circadian rhythm design specifically tailored to this diagnosis, consisting of five circadian rhythm protocols customized for each patient's individual treatment plan.

— We have carefully fine-tuned the dosage and timing of the light to achieve the optimal impact on different phases of the illness. It is a common requirement for all patients to have darkness during the night and appropriate lighting during the day. However, the specific amount of light and darkness needed varies depending on the phase. In the manic phase, patients benefit from fewer hours of bright light and more darkness, whereas patients in the depressive phase require more light for longer durations, explains Tone E. G. Henriksen.

At Valen Hospital, it is the responsibility of the physician or psychologist to prescribe the specific light therapy protocol for each individual patient. This decision is made during the daily treatment meetings, where medication is also prescribed.

— By utilizing multiple light protocols throughout the patient's hospitalization, we are able to stabilize their condition and reduce the severity of their illness, she adds.

Tailored to the patient's diagnoses and stages of illness

Chromaviso's circadian lighting has been clinically documented at Rigshospitalet Copenhagen and further developed for the psychiatric field at Psychiatric Center Copenhagen with the guidance of Professor Klaus Martiny, whom Tone E. G. Henriksen visited during her research trip before making the system selection.

—I had heard about Chromaviso as an excellent alternative to Trondheim's solution. Chromaviso is deeply rooted in science and has the expertise to develop the right light protocol. Their solution is also highly flexible, allowing us to easily adapt to the lighting as we gain new knowledge and encounter new patient groups. This was crucial for us, as purchasing a static system could quickly prove to be less than ideal, she explains.

The standard of the future

Moving forward, Tone E. G. Henriksen anticipates that circadian lighting will become a permanent fixture in the treatment of psychiatry and other specialities.

— We have the potential to significantly shorten the duration of treatment and effectively treat severely manic patients through controlled cycles of light and darkness. The combination of light therapy and medication has shown promising results, with a potential decrease in the need for medication when utilizing light and darkness as instrumental components of treatment. By incorporating light therapy, we can reduce the high doses of medication that patients often receive over extended periods, which is beneficial considering the potential negative side effects on their overall health. Ultimately, our goal is to make light and darkness therapy accessible to all patients, recognizing its significant benefits for their well-being.

Research findings on blocking blue light


  • Blocking the blue wavelengths of light resulted in a rapid and significant reduction in manic symptoms in bipolar patients in the manic phase (Cohen's d 1.86) compared to placebo.
  • The group of manic patients who received blue-blocking treatment experienced improved sleep efficiency, reduced movements during sleep, and fewer nighttime awakenings.
  • According to ISBD recommendations, light therapy is recommended as an adjunct treatment for bipolar depression, while dark therapy (blue-blocking) is recommended for manic episodes.

Published in reputable journals such as the Journal of Sleep Research, American Journal of Psychiatry, and Bipolar Disorders.