Light plays a role in reducing fear, anxiety and depression
By Liz Lockhart
Researchers from the University of Virginia have discovered that light plays a role in reducing fear and anxiety. The findings may augment the treatment of a variety of mental health disorders including depression, anxiety, panic disorder, phobias and post-traumatic stress disorder.
Using mice the research builds on earlier findings by biologists and psychologists showing that light has an affect on mood and the new study shows that light can modulate fear.
The researchers discovered that as mice are nocturnal animals, light enhances fear or anxiety in mice in much the same way that darkness can intensify fear or anxiety in diurnal humans.
The finding is published in the Journal proceedings of the National Academy of Science.
Brian Wiltgen, one of the researchers, said ‘We looked at the effect of light on learned fear, because light is a pervasive feature of the environment that has profound effect on behaiour and physiology.’
‘Light plays an important role in modulating heart rate, circadian rhythms, sleep/wake cycles, digestion, hormones, mood and other processes o the body. In our study we wanted to see how it affects learned fear.’
Fear is often an instinct and is natural mechanism for survival. Fears or reactions to loud noise, heights and sudden movements are innate. Also, humans and other mammals can earn from their experiences which may include dangerous or bad situations. This ‘learned fear’ can protect us from danger.
When this type of fear becomes abnormally accentuated it can lead to debilitating phobias.
Wiltgen added ‘Studies show that light influences learning, memory and anxiety. We have now shown that light also can modulate conditioned fear responses.’
‘In this work we describe the modulation of learned fear by ambient light,” said Ignacio Provencio, an expert on light and photoreception. ‘The dysregulation of fear is an important component of many disorders, including generalized anxiety disorder, panic disorder, specific phobias and post-traumatic stress disorder.’
‘Understanding how light regulates learned fear may inform therapies aimed at treating some of these fear-based disorders’ Provencio added.
‘The implications of this in humans is this: that being diurnal, the absence of light can be a source of fear,’ Wiltgen said. ‘But increased light can be used to reduce fear and anxiety and to treat depression.’
‘If we can come to understand the cellular mechanisms that affect this, then eventually abnormal anxiety and fear might be treated with improved pharmaceuticals to mimic or augment light therapy.’ Wiltgen concluded.
Source: University of Virginia
