Sham-Controlled Bright Light Study Shows Efficacy in Alleviating Anxiety Symptoms

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The bright light headset maker Valkee today announced the results of a new groundbreaking bright light study, showing statistically significant positive results in acutely alleviating anxiety symptoms.

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The invention of bright light headsets marks a leap forward in bright light research, as it is now finally possible to organize a sham-controlled double blind research setting.

The world’s first randomized, fully sham-controlled double blind trial of bright light treatment administered via ear canals brings sought-after new data to support the bright light studies carried out internationally since the 1980s.

Presented at the International Forum on Mood and Anxiety Disorders in Monte Carlo, the landmark results show a statistically significant acute reduction of anxiety symptoms in the bright light exposure group. In contrast, the symptoms in the control group receiving sham treatment did not show significant change. The double-blind trial was carried out under laboratory conditions using covered versions of Valkee bright light headsets, ensuring that neither participants nor research personnel were aware of which group a particular participant belonged to.

While the general perception of bright light treatment has been focused on Seasonal Affective Disorder (SAD), researchers have long been interested in wider scale benefits. Typical SAD symptoms such as tiredness and reduced cognitive performance are very similar to both general anxiety and to other specific anxiety-related disorders. The similarity is reflected in the US Diagnostic and Statistical Manual of Mental Disorders, which classifies SAD as a specific type of depression instead of an independent disorder.

About the Study

The new research results confirm earlier findings about the benefits of bright light in treating anxiety with a called-for randomized and controlled trial. A previous key milestone in this area was an open trial with a large sample of 79 participants reported by Youngstedt et al. in 2007. The study showed significant anxiety relieving effects following acute bright light exposure in adults with low anxiety levels.

The new double-blind study included 28 participants with moderate anxiety symptoms, randomly assigned into two groups. Half of the participants received a 12-minute daily dose of transcranial bright light using blinded Valkee bright light headsets, while the other half received the same duration of blinded sham exposure. The study was conducted during the spring and summer months.

“Studying the effects of bright light on anxiety symptoms in more general terms than only related to seasonal affective disorder makes perfect sense,” said Timo Takala, MD, Ph.D. and scientific advisor for Valkee. “Based on the new study, bright light acutely alleviates anxiety symptoms during the light period of the year and not only in relation to the dark period.”

“The invention of bright light headsets marks a leap forward in bright light research, as it is now finally possible to organize a sham-controlled double blind research setting,” said Heidi Jurvelin, Research Manager at Valkee who oversaw collaboration on the study with Oulu University. “With traditional desktop bright light devices, proper sham treatment is understandably impossible. Now we used identically blinded Valkee headsets for both actual and sham treatment, the only difference being inactivated light source for the sham group.”

The anxiety level of participants was first measured using the Beck Anxiety Inventory (BAI) score. The mean score of 19 ± 9 signals moderate anxiety symptoms. During the study, the anxiety symptoms were measured using the Spielberger State-Trait Anxiety Inventory (STAI, form Y1) self-rating questionnaire, 5 minutes before and 10 minutes after each exposure of bright light or sham treatment. The bright light group score decreased by 12.1 ± 7.3 %, while the sham group score decreased non-significantly by 3.7 ± 11.3 %. The difference between the groups is statistically significant.

The newly presented results will next be submitted for a peer-reviewed publication. The results also provide a solid “proof of concept” and warrant further anxiety-focused studies with large number of participants. The long-term scientific research and placebo-controlled studies carried out by the Valkee science team and researches in the University of Oulu in Finland and elsewhere build on an array of bright light studies published since the 1980s. The results have confirmed that bright light projected into the ear canal stimulates brain activity, and proved the efficiency of the ear canal as a channel for transmitting light to photosensitive areas of the human brain.

Valkee Bright Light Headset is the world’s first pocket-sized device that channels bright light via the ear canals into the brain. The device has a CE Class II(a) medical device certification for treating seasonal affective disorder (SAD) and is continuously clinically tested.

About Valkee:

Valkee is a health technology company focused on harnessing the benefits of bright light to the human mind and performance. Based on long-term scientific research and development work together with Finland’s Oulu University, Valkee introduced the world’s first bright light headset in 2010. Clinically tested to significantly relieve seasonal affective disorder symptoms in nine out of ten study participants, the Valkee user base has already grown to tens of thousands of people in 20+ countries. Of all Valkee users, 87% recommend Valkee to others. Additional tests and studies concerning the effects of bright light on cognitive and physical performance and jet lag, among other areas, are ongoing and planned. Founded in 2007, Valkee headquarters are located in Oulu, Finland. For more information, please visit and follow us at and

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Pekka Somerto, CEO
+358 408296343
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Timo Takala, MD, Ph.D., Scientific Advisor
+358 50 312 6902
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since: 04/2010
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