Verilux Happylight Liberty Full-Size VT20 Light Therapy Lamp ReviewSearching for different light sources is not an easy task. Our Verilux VT20 review will go into the features and benefits of this device. […]- What causes Seasonal Affective Disorder (SAD)One theory is that SAD may be caused by a lack of sunlight. Another theory suggests that SAD may be caused by an imbalance of neurotransmitters in the brain. […]