auditory stimulation

A Controlled Comparison of Audio-Visual Entrainment for Treating Seasonal Affective Disorder

Introduction. Seasonal Affective Disorder (SAD) affects up to 6% of the population, primarily in the winter months and at higher latitudes. Methods. Light-box therapy has been the traditional intervention for SAD, where the individual is exposed to a bright light for substantial periods in an effort to replace the lack of sunshine. Audio-visual entrainment (AVE) is a technique using flashing lights through a pair of specially designed glasses and pulses of tones through headphones. The expectation of AVE is to affect brain wave activity through auditory and visual stimulation at specific frequencies. The objective of this study was to determine if AVE is a viable treatment for SAD. The study involved 74 participants in a comparison design with a control group (no flashing lights or pulsed tones) and an AVE group that received a placebo treatment (AVE at 1 Hz flashing lights and pulsed tones) for 2 weeks, followed by an active treatment phase (20 Hz flashing lights and pulsed tones) for another 2 weeks. Results. The results indicated that the placebo phase produced mild reductions in depression and no improvements in anxiety sensitivity, whereas 20 Hz AVE reduced both depression and anxiety symptoms. Conclusion. The 20 Hz AVE treatment condition also produced significant improvements in social life with the family and at work, and increased happiness and energy. The 20 Hz treatment also produced a significant decrease in eating, appetite, and carbohydrate intake.